| insulin binding sites in gills of the estuarine crab chasmagnathus granulata. | bovine 125i-insulin was injected into the estuarine crab chasmagnathus granulata in order to study its distribution and specific uptake by tissues. the highest radioactivity uptake occurred in both anterior and posterior gills, which reached maximum values at 30-60 min following labeled insulin administration. heart and hepatopancreas concentrated a very low amount of radioactivity (only 9 and 3%, respectively, of that shown by gills). a significant reduction of the uptake was observed in the gi ... | 1997 | 9293637 |
| comparison between crab hepatopancreas and rat liver uroporphyrinogen decarboxylase. | we characterized uroporphyrinogen decarboxylase (urod) (e.c. 4.1.1.37) in hepatopancreas of the crab chasmagnathus granulatus as a first step to establish this enzyme as a possible biomarker for environmental contamination. we performed a comparative study of crab urod with the enzyme urod present in wistar rat liver, which is known as a useful indicator of intoxication by polyhalogenated aromatic hydrocarbons (pahs). the final products were the same in crab and rat urod: the remaining substrate ... | 2002 | 12381387 |
| effects of extracts from the cyanobacterium microcystis aeruginosa on ion regulation and gill na+,k+-atpase and k+-dependent phosphatase activities of the estuarine crab chasmagnathus granulata (decapoda, grapsidae). | recent discoveries indicate that microcystins affect enzymes, such as na(+),k(+)-atpase, involved in ion regulation of aquatic animals, through k(+)-dependent phosphatase inhibition. in vitro studies showed the inhibitory effect of microcystis aeruginosa extracts on na(+),k(+)-atpase and k(+)-dependent phosphatase activities in gills of chasmagnathus granulata (decapoda, grapsidae). extracts of m. aeruginosa were prepared from lyophilized or cultures cells of the cyanobacterium. for lyophilized ... | 2002 | 12601616 |
| effect of microcystin on ion regulation and antioxidant system in gills of the estuarine crab chasmagnathus granulatus (decapoda, grapsidae). | the objective of this work was to evaluate mechanisms of microcystin toxicity on crustacean species. adult male crabs of chasmagnathus granulatus (13.97+/-0.35 g) acclimated to low salinity (2 per thousand ) were injected with saline (control) or microcystis aeruginosa aqueous extract (39.2 microg/l) at 24 h intervals for 48 h. after the exposure period, the anterior and posterior gills were dissected, measuring na(+),k(+)-atpase and glutathione-s-transferase (gst) activity. total oxyradical sca ... | 2003 | 12781842 |
| toxic effects of microcystins in the hepatopancreas of the estuarine crab chasmagnathus granulatus (decapoda, grapsidae). | microcystins are toxins produced by cyanobacteria, being toxic to aquatic fauna. it was evaluated alternative mechanisms of microcystins toxicity, including oxidative stress and histopathology in the hepatopancreas of the estuarine crab chasmagnathus granulatus (decapoda, grapsidae). microcystins was administered to crabs (mic group) over 1 week, whereas the control (ctr group) received the saline from cyanobacteria culture medium. at day 7, catalase activity was higher in the mic than in the ct ... | 2003 | 12965191 |
| antioxidant responses and oxidative stress after microcystin exposure in the hepatopancreas of an estuarine crab species. | antioxidant responses and oxidative stress were evaluated in the hepatopancreas of the estuarine crab chasmagnathus granulatus (decapoda, brachyura) after oral microcystin administration. responses were evaluated through antioxidant enzyme activities (catalase-(cat), superoxide dismutase, glutathione-s-transferase- (gst)). nonproteic sulfhydril (np-sh) groups, oxygen consumption, lipid peroxides (lpo), and oxidized proteins were also measured. microcystin administration increased the oxygen cons ... | 2005 | 15922801 |
| biochemical and physiological responses after exposure to microcystins in the crab chasmagnathus granulatus (decapoda, brachyura). | microcystins are usually the predominant cyanotoxins present in both drinking and recreational waters after cyanobacterial blooms. their classic toxic effect is hepatotoxicity through inhibition of serine/threonine phosphatases. however, recent studies also reported oxidative stress generation and disruption of ion regulation in aquatic organisms after microcystins exposure. in the present study, aqueous extracts of microcystis aeruginosa were administered to the estuarine crab chasmagnathus gra ... | 2006 | 16137763 |
| effect of melatonin in the antioxidant defense system in the locomotor muscles of the estuarine crab neohelice granulata (decapoda, brachyura). | in vertebrates, many studies verified different effects of melatonin in the antioxidant defense system (ads). in crustaceans, few studies have been conducted to verify this possibility. we verified the melatonin effects in the crab neohelice granulata using low (0.002 and 0.02 pmol/crab) and high (2.0 and 20.0 pmol/crab) melatonin dosages in short-term (0.5h) and long-term (9.5h) experiments. we analyzed the antioxidant capacity against peroxyl radicals (acap), reactive oxygen species (ros) conc ... | 2010 | 19818787 |
| in vitro insulin stimulatory effect on glucose uptake and glycogen synthesis in the gills of the estuarine crab chasmagnathus granulata. | the aim of the present study was to examine the effects of insulin on glucose uptake and glycogen synthesis in crab chasmagnathus granulata gills. we observed an increased glucose uptake and incorporation of d-[(14)c]glucose into glycogen when posterior c. granulata gills were incubated in the presence of insulin; however, this was not observed in anterior gills, despite the presence of similar insulin receptors. in posterior gills, basal glucose uptake in the summer was significantly higher tha ... | 2002 | 11884071 |
| angiotensin ii enhances long-term memory in the crab chasmagnathus. | an opaque screen moving overhead provokes an escape response in the crab chasmagnathus granulatus that habituates after a few presentations of the eliciting stimulus. fifteen trials with a 180-s intertrial interval or 30 trials with a 90-s interval (strong training protocol) ensures long-term habituation (lth) of the response for 24 h, whereas 10 trials (weak training protocol) fail to induce it. however, robust lth is obtained when crabs are injected with human angiotensin (all; 50 pmol) immedi ... | 1996 | 8924030 |
| cadmium and zinc in mar chiquita coastal lagoon (argentina): salinity effects on lethal toxicity in juveniles of the burrowing crab chasmagnathus granulatus. | the large argentine marine littoral zone is characterized by great number of wetlands and includes only one coastal lagoon, mar chiquita, which has been declared as a biosphere reserve by the man and biosphere reserve program from unesco. its margins present populations of chasmagnathus granulatus, a semiterrestrial crab distributed along wide salinity gradients that plays an important role as a key species within the corresponding trophic web. dissolved cadmium (cd) and zinc (zn) concentrations ... | 2008 | 18071782 |
| influences of sex, habitat, and seasonality on heavy-metal concentrations in the burrowing crab (neohelice granulata) from a coastal lagoon in argentina. | cadmium, chromium, copper, and manganese concentrations were determined in hepatopancreas of both sexes as well as in eggs at different embryonic development stages of the burrowing crab neohelice granulata (brachyura, varunidae) from mar chiquita coastal lagoon, a biosphere reserve from argentina, during a period of 1 year, to assess the bioaccumulation of metals associated with sex and seasonality. furthermore, metal levels in associated superficial sediment samples were also determined. two d ... | 2010 | 19851703 |
| acute and chronic effects of parathion and 2,4 d on the oxygen consumption of chasmagnathus granulata (decapoda, brachyura). | the effect of two pesticides widely used in argentina on the oxygen consumption of the estuarine crab chasmagnathus granulata was studied. constant pressure respirometers were employed to estimate the rate of oxygen consumption per weight unit of animals treated previously with each pesticide, both acute (96 h) and chronically (15 and 30 days). crabs exposed to parathion -an organophosphorate insecticide that causes the inhibition of acetylcholinesterase- show an increase of oxygen consumption a ... | 2006 | 1797200 |
| effect of morphine and naloxone on a defensive response of the crab chasmagnathus granulatus. | male crabs (chasmagnathus granulatus) exhibited a defensive response (dr) to an electric shock (8 v, 50 hz, 1 sec). the dr so elicited was used as a model for studying the antinociceptive effect of morphine. injections of morphine-hcl (mp) (25, 50, 100 and 150 micrograms/g) were administered and the dr was examined at 2, 7.5, 15, 30, 45 and 75 min post-injection. (a) mp produced a dose-dependent reduction of the crab's sensitivity to the nociceptive stimulus. (b) a 100 micrograms/g dose of mp ca ... | 2011 | 3211972 |
| carriage of clostridium perfringens by benthic crabs in a sewage-polluted estuary. | the estuary of bahía blanca (ebb), argentina, is an important wetland under intense sewage pollution. we investigated the occurrence of clostridium perfringens (cp) in populations of two benthic crabs (neohelice granulata and cyrtograpsus angulatus) and in sediment from the ebb. cp was found in 49.1% of the crabs and all of the isolates were identified as type a. the alpha (cpa) and enterotoxin (cpe) encoding genes were identified. genetic analyses identified 13 novel sequence types, and found n ... | 2015 | 26130524 |
| evidence for the involvement of the crustacean hyperglycemic hormone in the regulation of lipid metabolism. | effects of the crustacean hyperglycemic hormone on total lipids in the hemolymph of chasmagnathus granulata and on free fatty acids, phospholipids, and triglycerides in the hemolymph of carcinus maenas, as well as on their release by orconectes limosus hepatopancreas in vitro, were investigated. eyestalk ablation led to a significant decrease of total lipids in the hemolymph of c. granulata and of free fatty acid levels in c. maenas. crustacean hyperglycemic hormone injections completely reverse ... | 2011 | 9237301 |
| effects of crustacean hyperglycemic hormones from carcinus maenas and orconectes limosus on blood and muscle glucose and glycogen concentration of chasmagnathus granulata. | the effects of purified crustacean hyperglycemic hormones (chh) from carcinus maenas or orconectes limosus, and of eyestalk extract of chasmagnathus granulata on the blood and muscle glucose and glycogen concentration of chasmagnathus granulata were investigated. different groups of animals (at least 7 animals per group) were injected with chh from either c. maenas or o. limosus chh dissolved in saline (16 pmol/animal) or crude eyestalk extract of c. granulata (1 eyestalk equivalent/animal). all ... | 1993 | 8136730 |
| effects of serotonin and fluoxetine on blood glucose regulation in two decapod species. | one of the best known crustacean hormones is the crustacean hyperglycemic hormone (chh). however, the mechanisms involved in hormone release in these animals are poorly understood, and thus constitute the central objective of the present study. different groups of crustaceans belonging to diverse taxa (chasmagnathus granulata, a grapsid crab and orconectes limosus, an astacid) were injected with serotonin, fluoxetine, or a mixture of both, and glycemic values (c. granulata and o. limosus) and ch ... | 2001 | 11151031 |
| dietary copper absorption and excretion in three semi-terrestrial grapsoid crabs with different levels of terrestrial adaptation. | three species of phylogenetically related semi-terrestrial crabs (superfamily grapsoidea--sesarma rectum, goniopsis cruentata and neohelice granulata (formerly: chasmagnathus granulatus) with different degrees of terrestriality were studied to quantify the accumulation of copper (cu) in hemolymph, gills, hepatopancreas and antennal gland, and its excretion through the faeces. these crabs were fed for 15 days practical diets containing 0 (a), 0.5 (b), 1.0 (c), and 1.5% (d) of added cucl2 (corresp ... | 2008 | 18501679 |
| adaptation to hypoosmotic challenge in brachyuran crabs: a microanatomical and electrophysiological characterization of the intestinal epithelia. | besides its role in digestion and nutrient absorption, the crustacean gut participates in osmo/ionic regulation. we investigate microanatomy, ionic permeability and transepithelial electrophysiological parameters in the mid- and hindguts of three hyperosmoregulating crabs that inhabit estuarine waters (chasmagnathus granulata), brackish mangrove swamp (sesarma rectum) or freshwater (dilocarcinus pagei). the abdominal hindguts are cuticle lined, the single-layered epithelia consisting of narrow, ... | 2005 | 16161014 |
| active nacl absorption across posterior gills of hyperosmoregulating chasmagnathus granulatus. | split lamellae of posterior gills of chasmagnathus granulatus adapted to 2.5 per thousand salinity were mounted in a modified ussing chamber. with nacl-saline on both sides of the preparation a transepithelial voltage (v(te)) of 4.1+/-0.5 mv (outside positive) was measured. after voltage-clamping, the negative short-circuit current (i(sc)) amounted to -142+/-21 micro a cm(-2) at a conductance (g(te)) of 44+/-5 ms cm(-2). substitution of either chloride (by nitrate) or sodium (by choline) on both ... | 2003 | 12582144 |
| natural occurrence of white spot syndrome virus and infectious hypodermal and hematopoietic necrosis virus in neohelice granulata crab. | white spot syndrome virus (wssv) and infectious hypodermal and hematopoietic necrosis virus (ihhnv) are two infectious agents associated to economic losses in shrimp aquaculture. as virus spread occurs through vectors and hosts, this study sought to verify the presence of wssv and ihhnv in neohelice granulata crab from lagoa dos patos estuary in brazil and nearby shrimp farms. dna extractions were performed with phenol/chloroform protocol. molecular diagnosis was carried out by nested pcr for ws ... | 2013 | 23792092 |
| [the role of cytograpsus angulatus (crustacea; brachyura) in the life cycles of microphallus szidati (digenea; microphallidae) and falsifilicollis chasmagnathi (acanthocephala; filicollidae): various aspects of their ecological parasitology]. | based on a study of the larvae from two helminth species parasitizing the crab cyrtograpsus angulatus dana, 1851 (microphallus szidati martorelli, 1986 and falsifilicollis chasmagnathi holcman-spector et al., 1977), from mar chiquita lagoom (argentina) together with the analyses of their life cycles and rates of prevalence, intensity and association coefficient (compared in definitive and intermediate host) the following conclusions have been reached: a) c. angulatus suns to be an excellent inte ... | 2007 | 2487452 |
| the effects of uv radiation on the visual system of the crab neohelice granulata: a protective role of melatonin. | the first and main target-structure of ultraviolet (uv) radiation in animals is the body surface, including the skin and eyes. here, we investigated cell damage in the visual system of the crab neohelice granulata acclimated to constant light and exposed to uva or uvb at 12:00 h for 30 min. the reactive oxygen species (ros) production, antioxidant capacity against peroxyl radicals (acap), lipid peroxidation (lpo) damage, catalase (cat) activity, and the melatonin immunohistochemical reactivity i ... | 2011 | 21854872 |
| effects of zinc on molting and body weight of the estuarine crab neohelice granulata (brachyura: varunidae). | the semiterrestrial burrowing crab neohelice granulata is one of the main inhabitants of the supratidal and intertidal zones of brackish salt marshes, estuaries and coastal lagoons from south america's atlantic littoral. a large population of this species spreads out mar chiquita coastal lagoon (in argentina) and its corresponding wetlands, and is considered as a key species within this system. since high values of dissolved heavy metals (including zn) have been recently reported within mar chiq ... | 2010 | 19903568 |
| crab regulation of cross-ecosystem resource transfer by marine foraging fire ants. | permeability of boundaries in biological systems is regulated by biotic and/or abiotic factors. despite this knowledge, the role of biotic factors in regulating resource transfer across ecosystem boundaries has received little study. additionally, little is known about how cross-ecosystem resource transfer affects source populations. we used experiments, observations and stable isotopes, to evaluate: (1) the proportion of intertidal-foraging black fire ant (solenopsis richteri) diet derived from ... | 2011 | 21394518 |
| epigenetic mechanisms and memory strength: a comparative study. | memory consolidation requires de novo mrna and protein synthesis. transcriptional activation is controlled by transcription factors, their cofactors and repressors. cofactors and repressors regulate gene expression by interacting with basal transcription machinery, remodeling chromatin structure and/or chemically modifying histones. acetylation is the most studied epigenetic mechanism of histones modifications related to gene expression. this process is regulated by histone acetylases (hats) and ... | 2014 | 24978317 |