| effects of intravenous calcitonin on water, electrolyte, and calcium movement across in vivo rabbit jejunum and ileum. | the influence of intravenously administered synthetic salmon calcitonin on water, electrolyte and calcium fluxes in in vivo rabbit jejunum and ileum was examined. rabbits were divided into four groups: those receiving (1) saline intravenously while a glucose-free isotonic saline solution perfused the jejunum and ileum; (2) calcitonin intravenously while the same intestinal perfusate was used as in group 1; (3) intravenous saline while 10 mm glucose-isotonic saline solution perfused jejunum and i ... | 1977 | 13025 |
| pressor action of propranolol; with special reference to relationship between the pressor action and peripheral vascular tone. | we showed in previous studies that pro pranolol produced a pressor action in the rat, and that this action was also observed in the spinal rat infused with adrenaline, noradrenaline and a mixture of isoproterenol and vasopressin, but not with vasopression alone. the action was also observed in the guinea pig infused with adrenergic beta-stimulants. in the present work, conditions in the peripheral vessels in which propranolol observed in the spinal rat infused with a mixture of various doses of ... | 1976 | 13028 |
| immunofluorescence using dichlorotriazinylaminofluorescein (dtaf). i. preparation and fractionation of labelled igg. | dichlorotriazinylaminofluorescein (dtaf), the product of the reaction of aminofluorescein with cyanuric chloride, is an effective reagent for conjugating fluorescein to immunnoglobulins. dtaf has absorption and emission properties nearly identical to fluoresceinisothiocyanate (fitc) and dtaf and fitc-labelled antibodies are similar in terms of preparation and specificity of immlnofluorescence. however, dtaf is superior to fitc with regard to cost, purity and stability. also, dtaf-labelled rabbit ... | 1976 | 13125 |
| brain concentrations of biogenic amines and their metabolites in two types of pyrogen-induced fever in rabbits. | | 1977 | 13153 |
| the effect of c.p.a.p. upon pulmonary reserve and cardiac output under increased abdominal pressure. | the cardiopulmonary effects of cpap under conditions of increased intra-abdominal pressure were studied using the rabbit as an experimental model. central venous pressure and cardiac output were reduced when the intra-abdominal pressure was increased. addition of cpap caused a further reduction in c.v.p. and c.o. despite these reductions cpap significantly improved arterial pao2 without significant effects on ph and paco2. the use of cpap in conditions associated with pulmonary dysfunction secon ... | 1977 | 13172 |
| activation of adenylate cyclase of rat ascites hepatoma by catecholamines and antagonism of beta-adrenergic blocking agents (author's transl). | | 1976 | 13194 |
| in vitro inhibition of rho-aminohippurate transport by halogenated anesthetics. | the effects of four commonly used halogenated anesthetic agents (methoxyflurane, halothane, enflurane and fluroxene) on rho-aminohippurate (pah) uptake by rabbit renal cortical slices were examined. all agents depressed pah uptake in a linear dose-dependent manner after 60 minutes of incubation and the effect was reversible. when the data were normalized for anesthetic potency, all agents exhibited a parallel dose-response curve. since these agents do not share a common metabolite, it is conclud ... | 1977 | 13202 |
| neurotransmission and glial cells: a functional relationship? | the investigations reported here demonstrate high affinity transport systems localized in glial cells which appear to be specific for amino acid neurotransmitter candidates. data on uptake of gamma-aminobutyric acid (gaba), glutamate, glycine, and taurine, show transport systems with kt's in the range of 10(-5) m. in addition, the distribution of the glial transport system for glycine is shown to parallel the presumed distribution of glycine as an inhibitory neurotransmitter. results of these st ... | 1976 | 13228 |
| marked difference in the susceptibility of several species to guanethidine-induced chemical sympathectomy. | | 1977 | 13257 |
| a note on the structure of immunized endplates. | | 1977 | 13400 |
| effect of several physical factors of the environment on indices of water-salt metabolism. | | 1976 | 13536 |
| effect of steroid saponins on blood serum proteins in experimental atherosclerosis in rabbits. | | 1976 | 13564 |
| cytochemical properties of the hematopoietic cells in hyporegenerative anemia under high mountain conditions. | | 1976 | 13572 |
| effect of cholera enterotoxin preparations on cutaneous response in rabbit under varied conditions. | enterotoxic activity of two preparations obtained from vibrio cholerae, b-53-6 inaba and b-53-10 ogawa was tested in ligated ileal loops of rabbit. the biologically active enterotoxic preparations were further used to study the permeability reaction in rabbit skin. cutaneous response tended to be linear only with higher concentrations of the toxin and showed maximum blueing intensity between 16 and 24 hrs of intracutaneous inoculation. exposure of enterotoxin preparations to elevated temperature ... | 1976 | 13591 |
| purification and properties of two protease inhibitors from rat skin inhibiting papain and other sh-proteases. | two papain inhibitors, i1 and i2, from rat skin extract were purified by affinity chromatography on kscn-modified papain-agarose gel and by gel filtration on sephadex g-100. i1 had a molecular weight of 74 000, a pi of 4.6, and it contained 4% of carbohydrates. i1 inhibited papain, ficin, bromelain, rat skin benzoylarginine-2-naphthylamide hydrolase, and to a minor extent, rat skin cathepsin c and bovine trypsin. bovine chymotrypsin or rat skin cathepsin d were not inhibited and benzoylarginine- ... | 1976 | 13595 |
| the role of carotid chemoreceptors in the regulation of arterial oxygen transport under hypoxia with and without hypercapnia. | | 1976 | 13620 |
| immunologic relations between cattle and ticks, specifically between cattle and boophilus microplus. | in the present investigation, it has been demonstrated that cattle become resistant to ticks after several heavy infestations, particularly with b. microplus. during development of the infestations, antibodies against salivary glands of b. microplus were detected using 2 techniques: indirect immunofluorescence and immunoelectrophoresis. there is a positive causal relationship between antibody titer and resistance development. two precipitating systems against b. microplus in infested cattle and ... | 1976 | 13630 |
| influence of host cell type on the density of herpes simplex virus particles. | the densities of purified herpes simplex virus (hsv) particles prepared from infected rabbit lung (zp) and baby hamster kidney (bhk-21) cells were investigated in potassium tartrate (pt) and potassium citrate (pc) density gradients. virions obtained from zp cells exhibited a higher density than those from bhk-21 cells. in pt and pc gradients, the former banded at densities of 1.226 and 1.267, while tha latter at 1.194 and 1.233, respectively. deenveloped viral particles prepared by nonidet p-40 ... | 1976 | 13640 |
| secretory state of gastric mucosa and resistance to injury by exogenous acid. | the capacity of the stomach to resist the effects of highly acid solutions was assessed by comparing the effects of such solutions on spontaneously secreting, stimulated, and inhibited gastric mucosae of rabbits in vivo and frogs in vitro. exposure of unstimulated resting mucosa to hc1, 120 mm, for 60 minutes produced superficial erosions in all rabbits, whereas such lesions were observed in only one of ten animals stimulated with histamine. metiamide obviated the protective effect of histamine ... | 1977 | 13668 |
| the kinetics of the alkaline dissociation of myosin. | | 1977 | 13734 |
| inhibition of prostaglandin biosynthesis by non-narcotic analgesic drugs. | the existence of a relationship between inhibition of prostaglandin biosynthesis and analgesic or anti-inflammatory activity was investigated in the case of the non-narcotic analgesics glafenine, floctafenine and clometacine, in comparison to indomethacin and acetylsalicylic acid. these compounds inhibit prostaglandin biosynthesis from arachidonic acid in a guinea-pig lung homogenate as strongly as indomethacin. on its biosynthesis in rat epididymal tissue stimulated by noradrenaline, glafenine ... | 1976 | 13749 |
| purification and properties of debranching enzyme from dogfish muscle. | glycogen debranching enzyme (4-alpha-glucanotransferase amylo-1,6-glucosidase, ec 2.4.1.25 + 3.2.1.33) was purified 140-fold from dogfish muscle in a rapid, high-yield procedure that takes advantage of a strong binding of the enzyme to glycogen, and its quantitative adsorption to concanavalin a-sepharose only when the polysaccharide is present. the final product was hrophoresis in the presence and absence of dodecyl sulfate. a molecular weight of 162,000 +/- 5000 was determined by sedimentation ... | 1977 | 13809 |
| ph-induced changes in the reactions controlled by the low- and high-affinity ca2+-binding sites in sarcoplasmic reticulum. | the effect of ph on the ca2+-binding sites of high and low affinity, located respectively on the outer and inner surfaces of the sarcoplasmic reticulum membrane, was investigated using intact and leaky sarcoplasmic reticulum vesicles. with the use of intact vesicles, different ph profiles of membrane phosphorylation and rates of nucleoside triphosphate hydrolysis were obtained depending on the assay temperature, on the ca2+ concentration, and on whether atp or itp was used as substrate. the diff ... | 1977 | 13812 |
| the reactivities of tyrosine and tryptophan residues in lipid-bound cytochrome b5. | purified cytochrome b5 from rabbit liver microsomes was bound to liposomes prepared from microsomal lipids. tyrosyl and tryptophyl side chains of the protein were modified by water-soluble reagents and the reactivities of these amino acid residues in the liposome-bound cytochrome b5 were compared to those of the free protein. at ph 13, 80% of the tyrosines in lipid-free cytochrome b5 ionized immediately, whereas in the lipid-bound protein only 65% ionized within the first minute. in contrast, ac ... | 1977 | 13832 |
| inactivation of mitochondrial 2-oxoglutarate dehydrogenase complex as a result of phospholipid degradation induced by freeze-thawing. | the inactivation of 2-oxoglutarate dehydrogenase complex by freeze-thawing was examined along with alterations of membrane phospholipids, in order to elucidate the mechanism of freezing injury in mitochondria. the dehydrogenase complex activity in slowly frozen and thawed mitochondria decreased to 70% as compared to intact mitochondria and further decreased during incubation. this inactivation during incubation was temperature dependent, i.e., at temperatures up to 25 degrees c there was a sligh ... | 1977 | 13867 |
| the selective action of beta-adrenoceptor blocking drugs and the nature of beta1 and beta2 adrenoceptors. | 1 purified membranes retaining a catecholamine responsive adenylate cyclase have prepared from rabbit heart, lung and (pseudo-pregnant) uterus. 2 these preparations have the characteristics of plasma membranes and both heart and lung respond to beta-adrenoceptor agonists in the order: (+/-)-isoprenaline greater than (-)-noradrenaline greater than (-)-adrenaline greater than (+)-isoprenaline greater than salbutamol. the sensitivity of the adenylate cyclase to beta-adrenoceptor stimulation is impr ... | 1977 | 13902 |
| measurement of carbon dioxide in blood. | the remarkable combination of physical and chemical properties displayed by carbon dioxide has enabled the development of a very wide variety of analytical methods for its measurement in blood or blood plasma. both for historical and technical reasons, the gasometric method of van slyke and neill is preeminent, but great skill is needed to realize its full precision and accuracy. the microgasometer of natelson, however, has served the clinical laboratory well as a practicable manual means of mic ... | 1976 | 13963 |
| the perinatal development of epoxide-metabolizing enzyme activities in liver and extrahepatic organs of guinea pig and rabbit. | we have measured the activities of epoxide hydrase in microsomes and glutathione s-epoxidetransferase and glutathione s-aryltransferase in cytosol fractions of liver, lungs, kidneys, and small intestine from fetal and neonatal guinea pigs and rabbits. the rates at which adult values of these enzyme activities are reached in extrahepatic tissues differ from the rates of maturation of the hepatic enzyme activities for both species. in addition, the two pathways of epoxide metabolism studied here d ... | 1977 | 13972 |
| biotransformation of d(-)-ephedrine and l(+)-ephedrine in the rabbit, in vivo and in vitro. | investigations were carried out with radiolabeled d(-)-ephedrine and l(+)-ephedrine to establish whether differences exist in their metabolic fate in the rabbit, in vivo and in vitro. in liver microsomal preparations, a) d(-)-ephedrine was metabolized at a faster rate than l(+)-ephedrine, b) benzoic acid was formed from d(-)ephedrine at a rate about three times greater than from the l(+)-isomer, and c) the relative amounts of norephedrine and 1-phenyl-1,2-propranediol formed from both ephedrine ... | 1977 | 13974 |
| stabilization of human beta-d-n-acetylhexosaminidase a towards proteolytic inactivation by coupling it to poly(n-vinylpyrrolidone). | human hexosaminidase a was covalently bound to soluble poly(n-vinylpyrrolidone), and the effect of this binding on the enzyme inactivation by various procedures was investigated. whereas the polymer-bound hexosaminidase underwent inactivation to the same extent as the free enzyme, when exposed to heat or acidic ph, the conjugation to polymer appeared to protect the enzyme towards proteolysis. thus, the polymer-bound enzyme exhibited considerably higher resistance to treatment of both pronase and ... | 1977 | 14004 |
| synthesis of norepinephrine from 3,4-dihydroxyphenylserine by l-aromatic amino acid decarboxylase of the rat brain and kidneys. | the enzymic decarboxylation of stereoisomers of dops was examined using rat brain and kidney decarboxylase. optimal assay conditions for racemic threo- and racemic erythro-dops decarboxylation were determined by the experiments concerning 1) time course, linear for 20 min, 2) optimal ph, ph 8.2, 3) optimal temperature, 37 degrees c except racemic l-threo-dops decarboxylation by kidney enzyme and 4) protein concentration, 1 to 5 mg in incubation medium. under the optimal assay condition, km of br ... | 1976 | 14060 |
| species distribution and properties of hepatic phenylalanine (histidine):pyruvate aminotransferase. | hepatic phenylalanine(histidine):pyruvate aminotransferase activity is much higher in the mouse and rat than in other animal species (human, guinea-pig, rabbit, pig, dog and chicken). the activity is elevated in the mouse and rat by the injection of glucagon but not in other species (guinea-pig, rabbit and chicken). the enzyme was purified from the mitochondrial fraction of mouse liver to homogeneity as judged by polyacrylamide disc gel electrophoresis in the presence of dodecylsulphate. with hi ... | 1977 | 14070 |
| mechanisms underlying the absorption of water and ions. | | 1977 | 14083 |
| proton inactivation of ca2+ transport by sarcoplasmic reticulum. | the effects of acid on fragmented sarcoplasmic reticulum from rabbit white skeletal muscle have been studied. brief exposure of sarcoplasmic reticulum membranes to ph values in the range 5.5 to 6.0 at 37 degrees caused rapid inactivation of calcium accumulation measured at 25 degrees in the presence of oxalate (calcium uptake) while (ca2+, mg2+)-atpase (ec 3.6.1.3) activity was enhanced by 75%. atpase activity, measured at 37 degrees in the absence of oxalate and in the calcium steady state, was ... | 1977 | 14142 |
| caclium uptake and associated adenosine triphosphatase activity in fragmented sarcoplasmic reticulum. requirement for potassium ions. | the effects of monovalent cations on calcium uptake by fragmented sarcoplasmic reticulum have been clarified. homogenization of muscle tissue in salt-containing solutions leads to contamination of this subcellular fraction with actomyosin and mitochondrial membranes. when, in addition, inorganic cations are contributed by the microsomal suspension and in association with nucleotide triphosphate substrates there is an apparent inhibition of the calcium transport system by potassium and other cati ... | 1977 | 14156 |
| human angiotensinogen. purification partial characterization, and a comparison with animal prohormones. | the renin-angiotensin system appears to play a major role in the regulation of sodium excretion and fluid intake in a wide variety of animal species from mammals to teleosts. in mammals the system has evolved further importance in terms of blood pressure homeostasis. this hormonal system in all species appears to involve a serum protein prohormone, angiotensinogen, a proteolytic enzyme, renin, and angiotensin i, the decapeptide product of the reaction between renin and angiotensinogen. the impor ... | 1977 | 14160 |
| regulation of rat liver acetyl coenzyme a carboxylase. evidence for interconversion between active and inactive forms of enzyme by phosphorylation and dephosphorylation. | | 1977 | 14161 |
| activation of the alternative pathway by pneumococcal cell walls. | the present studies were performed in order to identify the pneumococcal subcellular component responsible for activating the alternative pathway. purified pneumococcal cell walls were able to activate the alternative pathway at a concentration as low as 5 mug/ml and were more active than crude cell walls, which in turn were more active than the whole organism. purified pneumococcal cell membranes also were able to activiate the alternative pathway but had less than 10% of the activity of the pu ... | 1977 | 14211 |
| use of clindamycin-2-phosphate in ophthalmology (author's transl). | clindamycin-2-phosphate was studied to evaluate its possible use in ophthalmology. 1. sensitivity of organisms isolated from human clinical materials: of 44 staphylococcal strains in vitro studied 13 were highly sensitive to 0.1 mug/ml and 28 were resistant to 100 mug/ml or more of clindamycin-2-phosphate. 2. in experiments with rabbits, clindamycin-2-phosphate showed superior penetration into the ocular tissues after intravenous injection than after intramuscular injection. 3. clindamycin-2-pho ... | 1977 | 14269 |
| ascorbic acid blockade of muscle contractions by neurotransmitters and 2-aminoethanol. | | 1977 | 14285 |
| inhibition of adrenergic beta receptors by n,n'-bis-3-(2'ethoxyphenoxy)-2-hydroxypropyl-ethylenediamine (falirytmin) as compared to propranolol. | | 1976 | 14343 |
| the biosynthesis of dimethyltryptamine in vivo. | the in vivo formation of dimethyltryptamine was studied in rabbits, rats and monkeys. when c14-labelled n-methyltryptamine was administered by intravenous injection to rabbits, c14-dimethyltryptamine was found in lung, the principle site of the methyltransferase that biosynthesizes this psychotogen. unequivocal evidence for c14-dimethyltryptamine formation in rat tissues was not obtained. when rabbits were given non-radioactive n-methyltryptamine intravenously, dimethyltryptamine appeared in car ... | 1977 | 14361 |
| possible cyclic nucleotide regulation of calcium mediating myocardial contraction. | an inhibitor of adenylate and guanylate cyclases was tested on strips of left atria from rabbits. effects of catecholamines (cardiotonic) and of acetylcholine (cardiodepressive) were blocked, and positive force-frequency was converted to negative. ouabain produced only contracture without positive inotropy. the cardiotonic effect of increased calcium remained. data suggest that cyclic nucleotides modulate calcium associated with these stimuli. | 1977 | 14399 |
| pharmacological and biochemical properties of a toxin containing material from the jellyfish, cyanea capillata. | | 1977 | 14424 |
| hypothalamic mechanisms transforming nervous information into humoral information. | | 1976 | 14479 |
| effects of carbachol and calcium on the cyclic guanosine-3',5'-monophosphate (cyclic gmp) metabolism in intestinal smooth muscle. | in a submaximal concentration carbachol contracted the rabbit colon muscle and increased the cyclic gmp level. the cyclic amp level was reduced. in a ca++-depleted muscle carbachol reduced the cyclic gmp level while the effect on the cyclic amp content of the muscle was unchanged. carbachol had no effect on the guanylate cyclase activity of the "plasma membrane fraction" (the 35-45% fraction). in the homogenate and the microsomal fractions ca++ had no effect on the guanylate activity while it st ... | 1977 | 14481 |
| ionizing radiation and the immune response. | | 1976 | 14486 |
| the essential action of propranolol in hypertension. | the unique action of propranolol and other beta blockers in lowering raised arterial pressure is discussed. although the onset of the antihypertensive effect is not immediate, many trials have confirmed the efficacy of these drugs. animal experiments have thrown little light on the mechanism of action of beta blockers in hypertension: this may be because in animals, especially the rat, peripheral beta adrenoceptor vasodilatation is relatively more important than in man. five principal theories h ... | 1976 | 14498 |
| a smooth muscle active factor isolated from renal cortex of the rabbit. | homogenates of rabbit renal cortex contained a water-soluble material with striking activity on smooth muscle derived from the rabbit aorta, rat stomach, and guinea pig ileum--but not rat colon or chick rectum. evidence derived from the spectrum of its pharmacologic activity, the influence of specific competitive antagonists on the smooth muscle responses to the factor, the influence of proteolytic enzymes and its elution position during molecular sieve filtration on sephadex g-10 made it unlike ... | 1977 | 14508 |
| stimulants: interaction with clinically relevant drugs. | | 1976 | 14585 |
| simultaneous determination of skeletal muscle fiber, types i, iia, and iib by histochemistry. | we describe a simplified technique for the histochemical determination of three fiber types from a single section of skeletal muscle. preincubation in a solution of formaldehyde, glycine, and calcium followed by routine myofibrillar adenosine triphosphatase (atpase) incubation clearly differentiates type i, type iia, and iib fibers in human, rat, rabbit, and porcine muscle. in addition, glycine-formaldehyde-calcium preincubation offers better preservation of cytoarchitecture and standardization ... | 1977 | 14607 |
| physiological antagonism between pge2, pga1, pgf1-alpha and nadp, beta-nad on isolated rabbit jejunum. | the antagonistic action between the prostaglandins pge2, pga1 and pgf1-alpha, on the one hand, and nicotinamide-adenine-dinucleotide-phosphate (nadp or tpn) and beta-nicotinamide-adenine-dinucleotide (beta-nad or dpn) on the other, were experimentally studied on rabbit isolated jejunum. our results support our previously expressed hypothesis that in the living organism there exist regulatory systems to control the actions of extremely potent substances such as the pgs. nadp and beta-nad may ther ... | 1976 | 14647 |
| affinity labeling of rabbit muscle pyruvate kinase by 5'-p-fluorosulfonylbenzoyladenosine. | rabbit muscle pyruvate kinase is irreversibly inactivated upon incubation with the adenine nucleotide analogue, 5'-p-fluorosulfonylbenzoyladenosine. a plot of the time dependence of the logarithm of the enzymatic activity at a given time divided by the initial enzymatic activity(loge/eo) reveals a biphasic rate of inactivation, which is consistent with a rapid reaction to form partially active enzyme having 54% of the original activity, followed by a slower reaction to yield totally inert enzyme ... | 1977 | 14678 |
| conditions of spontaneous gelatinization of sarcoplasmic proteins. | ca2+ ions at low concentration (10(-4)-10(-5) m) when added to ultracentrifugates of sarcoplasmic proteins with minimal content of sarcoplasmic reticulum fragments completely prevent protein gelatinization or gels, formed in these conditions, quickly dilute. ca2+ ions at the concentration of 10(-3) m prevented in these conditions gelatinization in all the cases studied. strong gels of sarcoplasmic proteins are formed afterwards in weak acid (ph 6.1-6.75), neutral (ph 7.0) and weak alkaline (ph 7 ... | 1976 | 14719 |
| prazosin, a selective antagonist of post-synaptic alpha-adrenoceptors proceedings. | | 1977 | 14760 |
| a comparative study of alkaline phosphatase in calcifying cartilage, odontoblasts and the enamel organ. | the enzyme alkaline phosphatase (ap) (ec 3.1.3.1) in three different calcification areas was studied by means of a spectrophotometric micro method using p-nitrophenylphosphate as a substrate. rat maxillary incisor odontoblasts and enamel organ from the zones of matrix formation and maturation and tissue from rabbit metatarsal cartilage were allowed to react with the substrate in glycine-naoh buffer at room temperature. the reaction was found to be linear for a minimum of 20 min. the ph optima fo ... | 1977 | 14771 |
| influence of the ph on the antigen-antibody coupling in angiotensin i radioimmunoassay. its consequences for the determination of the plasma renin activity. | the antigen-antibody complex formation in the angiotensin i radioimmunoassay appears to be influenced by the ph of the radioimmunoassay incubation mixture. this may lead to erroneous results in the determination of the plasma renin activity, when an aliquot of a plasma sample, buffered at ph 6 for optimum renin activity is brought into a radioimmunoassay mixture of another ph, while the radioimmunoassay standards are not corrected for this ph shift. in our experiments we studied this general ph ... | 1977 | 14799 |
| effect of beta-adrenergic blockers on complement. | the authors, examined the effect of beta-adrenergic blockers propranolol, pindolol, practonol and p11 on complement in the serum of guinea pigs after continuous administration. the follow-up was made dynamicaly: on the 10th, 20th and 30th day. there was a considerable lowering of the complement level on the 20th and 30th day in all animals treated with beta-adrenergic blockers. the experiments in vitro showed that the effect of propranolol and and p11 on the serum of persons, guinea pigs and rab ... | 1976 | 14818 |
| participation of the adrenals in the pathogenesis of metabolic acid-base disorders. | the authors examined in dynamics the changes in the functional state of the adrenals on 240 rabbits, which served as models for acute metabolic deviations in the acid-base balance. the obtained results showed that the acute metabolic acidosis increased moderately the values of acth and 17-hydroxycorticosteroids in blood without changing their concentration on the adrenal tissue. it lowered strongly the content of catecholamines (adrenaline and noradranaline) in the adrenal medular part. the meta ... | 1976 | 14819 |
| carboxyl groups at the two active centers of sucrase-isomaltase from rabbit small intestine. | 1. seveal selective reagents were employed to identify the amino acid residues essential for the catalytic activity of sucrase-isomaltase. 2. modification of histidine, lysine and carboxyl residues resulted in a partial inactivation of the enzyme. substrates or competitive inhibitors provided protection against inactivation only in the reaction of carboxyl groups with carbodiimide (+lycine ethyl ester) or with diazoacetic ethyl ester. this indicated the occurrence of carboxyl groups at the two a ... | 1977 | 14830 |
| pharmacological characterisation of the presynaptic alpha-adrenoceptor in the rat vas deferens. | the interactions between alpha-adrenoceptor agonists and antagonists on the twitch response of the rat isolated vas deferens to low frequency motor nerve stimulatioh have been examined. oxymetazoline, clonidine, naphazoline and bay-1470 caused a concentration-dependent inhibition of the twitch response at concentrations lower than those causing smooth muscle stimulation. the twitch-inhibitory effect of these compounds is thought to result from stimulation of presynaptically located alpha-adrenoc ... | 1977 | 14838 |
| biochemical studies of the external and sphincter muscle of the rabbit. | | 1977 | 14841 |
| new developments in our knowledge of the chemistry of renin. | although the role of renin in hypertension continues to be incompletely defined, recent progress in the chemistry of renin has been considerable. extensive purifications of hog kidney renin and the renin-like mouse submaxillary gland enzyme have been achieved. various inhibitory peptides based on tetradecapeptide renin substrate have been useful in renin kinetic studies and in renin affinity chromatography. classification of renin as an acid protease results from its marked inhibition by pepstat ... | 1977 | 14850 |
| pharmacological analysis of effects of perimetazine on isolated smooth muscle. | effects of perimetazine on the motility of the isolated smooth muscle of guinea pig (ileum, taenia coli, uterus, vas deferens and trachea) and the ileum of rabbit were studied. the results obtained are as follows: perimetazine showed a specific antihistamine, antiadrenaline and antiserotonin action. moreover, antiacetylcholine and anti-bac12 actions were observed with high doses of perimetazine as well as chlorpromazine and such actions were attributed to the nonspecific direct action on the smo ... | 1976 | 14870 |
| studies of hyperimmune restricted and partially restricted anti-pneumococcal polysaccharide antibodies from allotype-defined pedigreed rabbits--v. variable region heavy chain sequence analysis of the cyanogen bromide c1 fragment obtained from an unusual restricted anti-sviii antibody from a homozygous a1 partially inbred rabbit. | | 1977 | 14888 |
| i-protein, a new regulatory protein from vertebrate skeletal muscle. iii. function. | i-protein inhibited themg-activated atpase ec 3.6.1.3 activity of actinomyosin by approximately 50% at low ionic strength. concomitantly, the onset of superprecipitation was retarded. i-protein was found to bind to myosin, but not to f-actin. the inhibitory action of i-protein occurred only in the absence of ca ions in the troponintropomyosin-actin myosin system. addition of ca ions abolished the effect. thus, it is very likely that i-protein prevents unnecessary hydrolysis of atp in the relaxed ... | 1977 | 14932 |
| kinetics of conformational change of troponin-c induced by proton binding or removal in the absence of calcium ions. | the kinetics of the conformational change of troponin-c induced by binding or removal of protons was studied by a stopped-flow ph-jump spectrofluorometric method. in the ph-down experiment (to investigate the kinetics of conformational change from the deprotonated state to the protonated state), a single first-order reaction with a rate constant and amplitude of 1.75-2.4 sec-1 and around 10% respectively, was observed. on the other hand, two first-order reactions with rate constants of 0.84-1.6 ... | 1977 | 14938 |
| self-assembly of myosin in vitro caused by rapid dilution. effects of hydrogen ion, potassium chloride, and protein concentrations. | the in vitro assembly of rabbit skeletal myosin was studied by flow birefringence. filaments were obtained from a solution of myosin in 0.5 m kcl by rapid dilution to lower ionic strength. in most cases, the filament length as determined from extinction angle measurements increased or decreased gradually for about 1 h after dilution, depending on ph, kcl concentration and the previous history. the filament length (l) immediately after dilution also showed a marked dependence on ph, kcl concentra ... | 1977 | 14939 |
| purification of hyaluronidase from human placenta. | hyaluronidase ec 3.2.1.35 was isolated from human placenta and purified by ammonium sulfate fractionation, deae-cellulose column chromatography and gel filtration on sephadex g-150. its isoelectric point was at ph 5.2 and the molecular weight was 7 x 10(4) based on sephadex g-200 gel filtration data. this enzyme was very stable at temperatures below 30 degree, but was almost completely inactivated at 60degree within 30 min. its optimum ph was 3.9, a characteristic property of a lysosomal hyaluro ... | 1977 | 14951 |
| effect of atherosclerosis on lysosomal cholesterol esterase activity in rabbit aorta. | radiolabeled cholesteryl oleate, when incorporated into phospholipid vesicles, was hydrolyzed at acid ph by an enzyme present in rabbit aortic homogenates. in contrast, cholesteryl oleate presented as an acetone dispersion was not effectively hydrolyzed at acid ph under identical conditions. using the vesicle preparation as substrate, a sensitive assay system for the acid hydrolase was developed in which hydrolysis was proportional to protein concentration and incubation time, and was independen ... | 1977 | 15038 |
| the identification and quantitation of the major metabolites of ethylamphetamine, produced by rabbit liver microsomal preparations. | amphetamine (i), 1-phenylpropan-2-ol (iii), phenylacetone (v), n-hydroxyethylamphetamine (vii), and alpha-methyl-n-(1'-phenylprop-2'-yl)nitrone (viii) were obtained as metabolic products from the incubation of ethylamphetamine (ii) with fortified male rabbit liver 9000 g supernatant fractions. these metabolites were identified by comparing their t.l.c., g,l.c. and g.l.c.-m.s. behaviour to that of reference compounds. a method for the quantitative analysis of the metabolites in mixtures using g.l ... | 1977 | 15071 |
| possible subdivisions among alpha-adrenoreceptors in various isolated tissues. | the ratio (expressed in log10 units) of the equieffective concentrations of (+)- and (-)-noradrenaline has been measured in a variety of isolated tissues in the presence of cocaine (1 x 10(-5) m), tropolone (3 x 10(-5) m) and (+/-)-propranolol (5 x 10(-7) to 5 x 10(-5) m). the values obtained fall into 3 distinct and statistically different groups. firstly, a high group comprising (mean +/- s.e.) mouse vasdeferens (2-78 +/- 0-04), rabbit duodenum (2-91 +/- 0-07) and ileum (2-86 +/- 0-05). second ... | 1977 | 15074 |
| hyperpyrexic interaction between debrisoquine and pethidine in rabbits. | pethidine injection into rabbits treated with debrisoquine either acutely or chronically resulted in severe interaction and fatal hyperpyrexia. pretreatment of rabbits with p-chlorophenylalanine, chlorpromazine, or crypoheptadine protected them against the interaction, while alpha-methyl-p-tyrosine was ineffective. in addition the administration of debrisoquine into 5-htp pretreated rabbits produced a severe interaction and hyperpyrexia. the hepatic n-demethylation of pethidine was significantly ... | 1977 | 15077 |
| uptake of uric acid by separated renal tubules of the rabbit. i. characteristics of transport. | a rapid filtration procedure was used to determine rates of uric acid uptake by a preparation of separated renal cortical tubules of the rabbit. the rate of uric acid uptake was temperature dependent and showed saturation kinetics with a k of 3.2 mm. the uptake was 50% lower when measured under nitrogen as compared with uptake under oxygen. the uptake rate increased with increasing sodium concentration and decreased with increasing potassium concentration. uptake was stimulated by citrate, succi ... | 1977 | 15103 |
| effect of ph on the ca2+-dependent atpase of rabbit cardiac and white skeletal myofibrils proceedings. | | 1977 | 15106 |
| involvement of cytochrome b5 in the oxidative desaturation of linoleic acid to gamma-linolenic acid in rat liver microsomes. | the effects of antibodies against microsomal electron-transport components on the in vitro activity of delta6-desaturation of linoleic acid to gamma-linolenic acid have been studied in intact microsomal membranes of rat liver. reduced nicotinamide adenine dinucleotide (nadh) or reduced nicotinamide adenine dinucleotide phosphate (nadph) (0.87 mm) served as electron donors, and effectively prompted the delta6-desaturase activities with yields of about 1.1 to 1.3 nmol per mg of protein in 10 min. ... | 1977 | 15177 |
| change in the activity of tyrosine aminotransferase in the tissues of rabbits with various levels of corticosteroids in the body. | experiments were conducted on rabbits. as revealed, hypocoriticism was accompanied by a reduction of the tyrosineaminotranspherase in the liver, muscles and blood plasma; the enzyme activity was unchanged in the brain and the spleen. an increase of the corticosteroid level in the organism after the administration of hydrocortisone to the intact and adrenalectomized animals led to increase of the enzyme activity in the tissues under study; the effect of hydrocortisone action depended on the initi ... | 1977 | 15244 |
| 31p nuclear magnetic resonance studies of glycogen phosphorylase from rabbit skeletal muscle: ionization states of pyridoxal 5'-phosphate. | 31p nuclear magnetic resonance (nmr) at 72.8 mhz has been used to study glycogen phosphorylase from rabbit muscle (1,4-alpha-d-glucan:orthophosphate alpha-glucosyltransferase, ec 2.4.1.1) at concentrations as low as 25 mg/ml, using a wh-180 wide-bore superconducting spectrometer. the use of a thio analogue for 5'-amp and arsenate for inorganic phosphate allowed the observation of three distinct forms of enzyme-bound pyridoxal 5'-phosphate at --0.2 ppm (form i), --2 to --3 ppm (form ii), and --3. ... | 1977 | 15256 |
| recognition of two intracellular cobalamin binding proteins and their identification as methylmalonyl-coa mutase and methionine synthetase. | the granulocyte r-type cobalamin binding protein delivers cobalamin (cbl) exclusively to hepatocytes, and transcobalamin ii delivers cbl to various mammalian cells. both protein-cbl complexes enter cells by pinocytosis, and the protein moieties are rapidly degraded in lysosomes. the liberated cbl is subsequently bound to a high-molecular-weight intracellular cobalamin binding protein (icb). the nature of icb-cbl is unknown but appears important because icb-57cocbl is missing from cultured fibrob ... | 1977 | 15259 |
| physiological and metabolic aspects of freezing erythrocytes, with historical notes. | | 1976 | 15282 |
| beta-adrenergic blocking agents atp and anabolic hormones in the treatment of ischemic heart disease. | | 1977 | 15321 |
| the effects of pco2 and ph on platelet shape change and aggregation for human and rabbit platelet-rich plasma. | | 1977 | 15330 |
| glucose transport across the mucosa of the small intestine. | the rate of glucose absorption in an isolated loop of the small intestine in rats was measured. the maximum rate of absorption was registered with 3 and 5 per cent concentrations, while 1 and 10 per cent solutions are absorbed at a slower rate. the absorption rate of 5 per cent glucose solution did not materially change for one hour after a sugar load. the small intestine mucosa transports glucose from a 5 per cent solution at an equal rate in rats and rabbits, i. e. 139+/-4 and 143+/-6 gamma/cm ... | 1976 | 15346 |
| our views on the function of the hippocampus and connected structures in the process of information storage. | | 1976 | 15358 |
| susceptibility of various cell lines to virulent an attenuated strains of pseudorabies virus at supraoptimal temperature. | replication of virulent and attenuated strains of pseudorabies virus (prv) at supraoptimal temperature was studied in rabbit lung (zp), pig kidney (ps), and bhk-21 cells adapted and non-adapted to 40 degrees c and l, hela and human amniotic (am) cells non-adapted to 40 degrees c. the temperature of 40 degreec did not influence the type cytopathic effect (cpe) in either adapted or non-adapted cells. according to the susceptibility at 40 degrees c the cells could be divided into three groups: cell ... | 1977 | 15434 |
| japanese encephalitis virus multiplication in the regional rabbit ear vein in the early viremic period. | | 1977 | 15444 |
| heterogeneity of the antibody response to pneumoccal capsular polysaccharides types iii and viii (siii and sviii). | | 1977 | 15498 |
| comparative subcutaneous absorption of local anesthetics: lidocaine, procaine and tetracaine. | the ph partition hypothesis was applied to the absorption of ionizable local anesthetic amines through the subcutaneous (s.c.) route. solutions of lidocaine hydrochloride (lhcl), procaine hydrochloride (phcl) and tetracaine hydrochloride (thcl) at various ph were implanted on s.c. animal tissue through a glass absorption cell. the s.c. absorption of these drugs was evaluated from the clearances' slopes evolved by determination of the drugs' concentrations in the cell at definite intervals. the h ... | 1977 | 15527 |
| the use of gadolinium as a probe in the fc region of a homogeneous anti-(type-iii pneumococcal polysaccharide) antibody. | the binding of gadolinium gd(iii) to a homogeneous rabbit anti-(type-iii pneumococcal polysaccharide) igg (immunoglobulin g) and its fab (n-terminal half of heavy and light chain) and fc (c-terminal half of heavy-chain dimer) fragments was demonstrated by measurements of solvent-water proton relaxation rates in the appropriate gd(iii) solutions. at ph 5.5 the binding of gd(iii) to the fc fragment is much tighter (kd approx. 5 micronm) than binding to the fab fragment (kd approx. 250 micronm). th ... | 1977 | 15542 |
| occurrence of ornithine decarboxylase and polyamines in cartilage. | the activity of ornithine decarboxylase was investigated in cartilage from chick embryos, rabbits, rats and human foetuses. the enzyme activity in these cartilages was of the same order as the detected in other body tissues. ornithine decarboxylase activity in chick-embryo cartilage and liver was the same when compared on the basis of total soluble tissue protein. the cartilage enzyme exhibited a ph optimum of 6.5 and a km for ornithine of 0.16mm. ornithine decarboxylase activity in chick-embryo ... | 1977 | 15559 |
| the roles of cytochrome b5 in a reconstituted n-demethylase system containing cytochrome p-450. | | 1977 | 15564 |
| action of partially cyclic and ring methylated nikethamide analogs. structure-activity relationships of analeptics of the nicethamide type. | investigation concerning the respiratory-analeptical effect of partially cyclic and ring methylated nicethamide analogues are reported. the respiration of the rabbit determined by the mask method, served as pharmacological model. | 1977 | 15569 |
| an investigation of heavy meromyosin-adp binding equilibria by proton release measurements. | the interaction of magnesium-adp with skeletal muscle heavy meromyosin has been studied by measuring the accompanying release of protons. total ph changes of the order of 0.03 were involved, and measurements were performed with a discrimination of some ten-thousandths of a ph unit. at ph 8.0 and 25 degrees c about 0.5 mol of protons per mol of heavy meromyosin is released at saturation. a stoichiometry of binding close to 2 mol of adp per mol of protein was found, with a binding constant, obtain ... | 1977 | 15588 |
| preparation of renal cortex basal-lateral and bursh border membranes. localization of adenylate cyclase and guanylate cyclase activities. | luminal brush border and contraluminal basal-lateral segments of the plasma membrane from the same kidney cortex were prepared. the brush border membrane preparation was enriched in trehalase and gamma-glutamyltranspeptidase, whereas the basal-lateral membrane preparation was enriched in (na+ + k+1)-atpase. however, the specific activity of (na+ + k+)-atpase in brush border membranes also increased relative to that in the crude plasma membrane fraction, suggesting that (na+ + k+)-atpase may be a ... | 1977 | 15597 |
| modulation of protein phosphorylation by a factor purified from adipocytes. | 1. a factor which modulates the activity of cyclic amp-dependent protein kinase copurifies from rat adipocytes with an inhibitor of adenylate cyclase. purification and stability studies suggest that both effects reside in a single factor previously referred to as a feedback regulator. 2. the magnitude and direction of the feedback regulator effect on cyclic amp-dependent protein kinase activity was dependent on the concentration of feedback regulator and the concentration and type of protein sub ... | 1977 | 15626 |
| high and low affinity ca2+ binding to the sarcoplasmic reticulum: use of a high-affinity fluorescent calcium indicator. | the fluorescent calcium indicator, calcein, has been used as a high-affinity indicator of ca2+ in the aqueous phase at physiological ph in the study of high-affinity calcium binding to sarcoplasmic reticulum (sr). the binding constant of the indicator at physiological ph is 10(3)-10(4) m-1 and increases with increasing ph. the binding mechanism of the indicator with ca2+ and mg2+ is described. application of calcein as an aqueous indicator of ca2+ binding to the sr at room temperature has reveal ... | 1977 | 15667 |
| increase in the oxygen available to the cerebral cortex after the administration of carbonic anhydrase inhibitors. | oxygen tension (po2) in cerebral cortex was measured by polarographic method in unanesthetized rabbits. intravenous administration (25 mg/kg) of carbonic anhydrase inhibitors (acetazolamide, methazolamide, dichlorphenamide, sulthiame) induced an early important rise of cortical p o2, which is not dependent on increase of p o2 and p co2 and decrease of ph in arterial blood. high dosage of acetazolamide (250 mg/kg) produced the same effect and did not suppress the increase of cortical p o2 under a ... | 1977 | 15731 |
| valsalva vasoconstrictor reflex in human hypertension in after beta-adrenoreceptor blockade in conscious rabbits. | 1. a valsalva-like manoeuvre was used to elicit graded rises in total peripheral resistance (tpr) in conscious rabbits. the rises were reflex and mediated through sympathetic constrictors. propranolol infused at different rates reaching plasma concentrations up to 240 (sem 33) ng/ml had no effect on this reflex but reduced mean arterial pressure. however, the response was attenuated by clonidine in a dose-dependent manner. 2. valsalva manoeuvres were used to elicit graded sympathetically mediate ... | 1976 | 15755 |
| interactions of divalent cations and nucleotides with solubilized cardiac guanylate cyclase. | some properties of guanylate cyclase, which was solubilized from the rabbit heart washed particles by the treatment with triton x-100, were investigated. the solubilized enzyme activity was stimulated by mg2+ in the presence of low (subsaturating) mn2+ (gtp is greater than mn2+); under these conditions, ga2+ was inhibitory. at subsaturating mngtp and free mn2+, the solubilized enzyme was markedly stimulated by mngdp and mnatp; cagtp on the other hand, was inhibitory. these results are consistent ... | 1977 | 15829 |
| antibodies and autoantibodies of glycogen phosphorylase b: inactivation of pig and rabbit enzymes. | pig skeletal muscle glycogen phosphorylase b was purified using ammonium sulfate fractionation, deae-sephadex a-50 and sephadex g-200 column chromatography. the purified enzyme was used to immunize rabbits in the presence or in the absence of complete freund adjuvant. antibodies against pig phosphorylase in pure form were isolated from rabbit antisera using insoluble immunoadsorbents of pig phosphorylase. autoantibodies against the rabbit enzyme were obtained from the same antisera using insolub ... | 1977 | 15834 |