| thaulin-1: the first antimicrobial peptide isolated from the skin of a patagonian frog pleurodema thaul (anura: leptodactylidae: leiuperinae) with activity against escherichia coli. | patagonia's biodiversity has been explored from many points of view, however, skin secretions of native amphibians have not been evaluated for antimicrobial peptide research until now. in this sense, pleurodema thaul is the first amphibian specie to be studied from this large region of south america. analysis of cdna-encoding peptide in skin samples allowed identification of four new antimicrobial peptides. the predicted mature peptides were synthesized and all of them showed weak or null antimi ... | 2017 | 28025119 |
| new records of batrachochytrium dendrobatidis in chilean frogs. | we used molecular techniques to examine 11 species of frogs in 6 localities in southern chile to ascertain the incidence of the chytrid fungus batrachochytrium dendrobatidis (bd). we detected the fungus in 2 localities (coñaripe and raúl marín balmaceda) in 3 species: batrachyla leptopus, pleurodema thaul and rhinoderma darwinii. our findings expand the list of bd hosts to include b. leptopus and p. thaul and extend the spatial distribution in chile to include the southernmost bd record at raúl ... | 2011 | 21932539 |
| fenoterol stimulation of sodium transport in the isolated toad skin: a beta adrenergic effect. | 1. this work examines the effects of fenoterol on the isolated skin of the chilean toad pleurodema thaul. 2. a dose-dependent increase in the potential difference and in the short-circuit current of the skin was found. furthermore, sodium potential (ena) and sodium conductance (gna) also rose. 3. the increase in bioelectric parameters was reversibly blocked by propranolol, was not significantly affected by reserpinization and was not calcium-dependent. 4. the skin response was significantly redu ... | 1988 | 2831108 |
| the antiepileptic drug phenytoin affects sodium transport in toad epithelium. | the effects of phenytoin on isolated pleurodema thaul toad skin were investigated. low (micromolar) concentrations of the antiepileptic agent applied to the outside surface of the toad epithelium increased the electrical parameters (short-circuit current and potential difference) by over 40%, reflecting stimulation of na(+) transport, whereas higher (millimolar concentrations, outside and inside surface) decreased both electric parameters, the effect being greater at the inside surface (40% and ... | 2019 | 16314149 |
| temporal selectivity for complex signals by single neurons in the torus semicircularis of pleurodema thaul (amphibia:leptodactylidae). | responses of auditory neurons in the torus semicircularis (ts) of pleurodema thaul, a leptodactylid from chile, to synthetic stimuli having diverse temporal patterns and to digitized advertisement calls of p. thaul and three sympatric species, were recorded to investigate their temporal response selectivities. the advertisement call of this species consists of a long sequence of sound pulses (a pulse-amplitude-modulated, or pam, signal) having a dominant frequency of about 2000 hz. each of the s ... | 1997 | 9106995 |
| the antiepileptic drug carbamazepine affects sodium transport in toad epithelium. | the present work investigates the effects of the antiepileptic drug carbamazepine (cbz) on sodium transport in the isolated skin of the toad pleurodema thaul. a submaximal concentration of the drug (0.2 mm) applied to the outer surface of the epithelium increased the electrical parameters short-circuit current (isc) and potential difference (pd) by over 28%, whereas only a higher concentration (1 mm) induced over a 45% decrease in these parameters when applied to the inner surface. the amiloride ... | 2006 | 16542818 |
| sodium arsenite affects na+ transport in the isolated skin of the toad pleurodema thaul. | arsenic, applied as sodium arsenite (as(iii)) to either inner or outer surfaces of the isolated toad skin, dose-dependently decreased the short-circuit current (isc), potential difference (pd) and sodium conductance (g(na)) in the concentration range 1-1000 microm, with effects often lasting over 3 h. maximal inhibitory effect was over 90% with an ic(50) of about 34 microm. applied during amiloride block, as(iii) did not change this effect. however, an increase in electric parameters was noted d ... | 2013 | 17055342 |
| correspondence between evoked vocal responses and auditory thresholds in pleurodema thaul (amphibia; leptodactylidae). | thresholds for evoked vocal responses and thresholds of multiunit midbrain auditory responses to pure tones and synthetic calls were investigated in males of pleurodema thaul, as behavioral thresholds well above auditory sensitivity have been reported for other anurans. thresholds for evoked vocal responses to synthetic advertisement calls played back at increasing intensity averaged 43 db rms spl (range 31-52 db rms spl), measured at the subjects' position. number of pulses increased with stimu ... | 2008 | 18214495 |
| the identity of rana lutea molina, 1782 (amphibia, anura). | rana lutea is one of the two anuran species described in 1782 by the chilean born priest and naturalist juan ignacio molina, and its nomenclatural history is confusing. after a detailed revision of the pertinent literature, we demonstrate that bufo thaul schneider, 1799, is a junior objective synonym of rana lutea molina, 1782, but based on the usage of both nomina, we revert the precedence and consider rana lutea molina, 1782 as a nomen oblitum whereas bufo thaul schneider, 1799 is a nomen prot ... | 2013 | 24614468 |
| the effects of pentachlorophenol (pcp) at the toad neuromuscular junction. | 1. effects of pcp at the frog neuromuscular junction were studied in vitro in sciatic nerve sartorius muscle of the toad pleurodema-thaul. 2. within the concentration 0.003-0.1 mm, pcp caused a dose-time-dependent block of evoked transmitter release acompanied by an increase in the rate of spontaneous quantal release. 3. pcp induced an increase in miniature endplate potential (mepp) frequency and it was not antagonized in a ca2(+)-free medium, indicating that it does not depend upon ca2+ influx ... | 1990 | 1980876 |
| [histologic study of the lumbar glands of pleurodema thaul (amphibia, anura, leptodactylidae)]. | frogs of the pleurodema thaul species have a pair of prominent elevated cutaneous glands dorsolaterally, just posterior to the sacrum, which are named lumbar glands. we have studied histologically these glands and found that their chromatophores are disposed mainly immediately under the epidermis structuring a dermal chromatophore unit. similar to the other anuran macroglands, the lumbar glands are constituted basically by granular alveoli filled with secretion. the presence of these granular al ... | 1989 | 2608945 |
| divergence of acoustic signals in a widely distributed frog: relevance of inter-male interactions. | divergence of acoustic signals in a geographic scale results from diverse evolutionary forces acting in parallel and affecting directly inter-male vocal interactions among disjunct populations. pleurodema thaul is a frog having an extensive latitudinal distribution in chile along which males' advertisement calls exhibit an important variation. using the playback paradigm we studied the evoked vocal responses of males of three populations of p. thaul in chile, from northern, central and southern ... | 2014 | 24489957 |
| geographic variation in acoustic communication in anurans and its neuroethological implications. | geographic variation of traits may represent the first step for evolutionary divergence potentially leading to speciation. signals are behavioral traits of particular interest for the study of variation at a geographic scale. the anuran acoustic communication system represents an excellent model for studies of this kind, because their vocalizations play a main role in reproduction and the extant variation in this system may determine the evolution of this group. this review is committed to studi ... | 2015 | 25446892 |
| impact of global warming at the range margins: phenotypic plasticity and behavioral thermoregulation will buffer an endemic amphibian. | when dispersal is not an option to evade warming temperatures, compensation through behavior, plasticity, or evolutionary adaptation is essential to prevent extinction. in this work, we evaluated whether there is physiological plasticity in the thermal performance curve (tpc) of maximum jumping speed in individuals acclimated to current and projected temperatures and whether there is an opportunity for behavioral thermoregulation in the desert landscape where inhabits the northernmost population ... | 2014 | 25512843 |
| lack of phonotactic preferences of female frogs and its consequences for signal evolution. | sexual selection is one of the main evolutionary forces that drive signal evolution. in previous studies, we have found out that males of pleurodema thaul, a frog with an extensive latitudinal distribution in chile, emits advertisement calls that show remarkable variation among populations. in addition, this variation is related to intense inter-male acoustic competition (intra-sexual selection) occurring within each population. however, the extent to which female preferences contribute to the s ... | 2015 | 26051194 |
| lack of functional link in the tadpole morphology induced by predators. | most studies of predator-induced plasticity have focused on documenting how prey species respond to predators by modifying phenotypic traits and how traits correlate with fitness. we have previously shown that pleurodema thaul tadpoles exposed to the dragonfly rhionaeschna variegata responded strongly by showing morphological changes, less activity, and better survival than non-exposed tadpoles. here, we tested whether there is a functional link between morphological plasticity and increased sur ... | 2016 | 29491910 |
| effects of cr(3+) ions on electrophysiological parameters of isolated skin of toad pleurodema thaul. | in view of the toxicity of chromium (cr(3+)) ions, it was explored the damaging effects that this ion could induce in cell membranes. the measurement of the effects induced by cr(3+) ions on electrophysiological parameters of short-circuit current and on the potential difference were investigated using the outer side (mucosal) and the inner side (serosal) of toad pleurodema thaul skin. the results showed a decreased on electrophysiological parameters when it were administered concentrations of 3 ... | 2020 | 27429927 |
| intraspecific geographic variation in thermal limits and acclimatory capacity in a wide distributed endemic frog. | intraspecific variation in physiological traits and the standard metabolic rate (smr) is common in widely distributed ectotherms since populations at contrasting latitudes experiences different thermal conditions. the climatic variability hypothesis (cvh) states that populations at higher latitudes presents higher acclimation capacity than those at lower latitudes, given the wider range of climatic variability they experience. the endemic four-eyed frog, pleurodema thaul is widely distributed in ... | 2017 | 29037391 |
| the acoustic adaptation hypothesis in a widely distributed south american frog: southernmost signals propagate better. | animal communication occurs in environments that affect the properties of signals as they propagate from senders to receivers. we studied the geographic variation of the advertisement calls of male pleurodema thaul individuals from eight localities in chile. furthermore, by means of signal propagation experiments, we tested the hypothesis that local calls are better transmitted and less degraded than foreign calls (i.e. acoustic adaptation hypothesis). overall, the advertisement calls varied gre ... | 2018 | 29725055 |
| natural selection on plasticity of thermal traits in a highly seasonal environment. | for ectothermic species with broad geographical distributions, latitudinal/altitudinal variation in environmental temperatures (averages and extremes) is expected to shape the evolution of physiological tolerances and the acclimation capacity (i.e., degree of phenotypic plasticity) of natural populations. this can create geographical gradients of selection in which environments with greater thermal variability (e.g., seasonality) tend to favor individuals that maximize performance across a broad ... | 2018 | 30459844 |
| the identity of the chilean amphibians collected by the united states exploring expedition. | between mid-may and early june of 1839, members of the united states exploring expedition collected diverse anurans in the environs of valparaíso, chile, later described by girard in 1853. of this set of species, metaeus timidus, described there as a new genus and species, attracts attention because is a name that practically disappeared from the herpetological literature. its identification, along with that of the other chilean taxa collected by the usee (cystignathus nebulosus girard, 1853, pl ... | 2019 | 31716446 |
| geography, temperature, and water: interaction effects in a small native amphibian. | amphibian locomotor capacity is strongly linked to temperature and hydration. however, organisms in nature experience covariation of multiple environmental factors, and thus to better understand the effects of thermal and hydric conditions on physiological performance, it is critical not only to experimentally disentangle them but also to incorporate potential interactive effects due to geographic variation. to this end, we selected two populations of the small amphibian pleurodema thaul inhabit ... | 2020 | 32762608 |
| effect of uv-b exposure on eggs and embryos of patagonian anurans and evidence of photoprotection. | in patagonia, enhanced levels of ultraviolet radiation (uvr) are affecting not only the southernmost territories but the northern as well, and there is a growing body of evidence indicating effects on terrestrial and aquatic communities. anurans occur along a wide geographical gradient in patagonia and are common in shallow waters, usually breeding during spring when seasonal uv-b radiation is at its highest level. in this paper we analyse the effective irradiances (i) experienced in nature by e ... | 2006 | 16890978 |
| validation of a cheap and simple nondestructive method for obtaining aflps and dna sequences (mitochondrial and nuclear) in amphibians. | the use of nondestructive methods for obtaining dna from amphibians (e.g. buccal swabs) allows genetic studies to be performed without affecting the survival of the studied individuals. in this study, we compared two methods of nondestructive dna sampling, buccal swabs and interdigital membrane or toe-clipping, in several amphibian species of different size: rhinella spinulosa, r. atacamensis, six species of the genus telmatobius and pleurodema thaul. we evaluated the integrity of the dna extrac ... | 2012 | 22978706 |
| how sensitive are temperate tadpoles to climate change? the use of thermal physiology and niche model tools to assess vulnerability. | ectotherms are vulnerable to climate change, given their dependence on temperature, and amphibians are particularly interesting because of their complex life cycle. tadpoles may regulate their body temperature by using suitable thermal microhabitats. thus, their physiological responses are the result of adjustment to the local thermal limits experienced in their ponds. we studied three anuran tadpole species present in argentina and chile: pleurodema thaul and pleurodema bufoninum that are seaso ... | 2018 | 29496379 |
| extended amplification of acoustic signals by amphibian burrows. | animals relying on acoustic signals for communication must cope with the constraints imposed by the environment for sound propagation. a resource to improve signal broadcast is the use of structures that favor the emission or the reception of sounds. we conducted playback experiments to assess the effect of the burrows occupied by the frogs eupsophus emiliopugini and e. calcaratus on the amplitude of outgoing vocalizations. in addition, we evaluated the influence of these cavities on the recepti ... | 2016 | 27209276 |
| body distribution of hannemania sp. (acari: leeuwenhoekiidae) in rhinella spinulosa, pleurodema bufonina, and pleurodema thaul from chile. | hannemania larvae are parasites of amphibians in north and south america. in chile, only one species of hannemania has been reported from batrachyla taeniata (banded wood frog). the objective of the study was to determine the abundance and body distribution of hannemania among three amphibians from antuco (biobío region, chile): pleurodema thaul (13 adults; chile four-eyed frog), pleurodema bufonina (5 adults; large four-eyed frog), and rhinella spinulosa (15 adults and 16 juveniles; warty toad) ... | 2016 | 27468033 |
| review of the genus <i>hannemania</i> (acari: leeuwenhoekiidae) with description the two new species in amphibians from chile. | the genus hannemania includes 25 species of parasites of amphibians; chile has one species: h. pattoni sambon, 1928. this work reviews the genus hannemania and describes two new species from chile: hannemania ortizi sp. nov., a parasite of pleurodema thaul (lesson) (anura: leptodactylidae) and eupsophus contulmoensis ortiz, ibarra-vidal, formas (anura: alsodidae) and hannemania gonzaleacunae sp. nov., a parasite of e. nahuelbutensis ortiz and ibarra-vidal (anura: alsodidae). the new species diff ... | 2016 | 27988610 |
| effects of cadmium on na+ transport in the isolated skin of the toad pleurodema thaul. | cadmium ions applied to either (outer or inner) surface of the isolated toad skin dose-dependently increased the short-circuit current (scc), the potential difference (v) and the active sodium conductance (g(na)) in the concentration range 0.07-0.50mm. maximal stimulatory effect was over 30% with an ec(50) of about 0.1mm. the effect of the highest concentration used (0.75mm) decreased considerably, and when it was applied to the inner surface (10 experiments), induced between 30% and 40% inhibit ... | 2005 | 16266750 |
| effects of pb2+ ions on na+ transport in the isolated skin of the toad pleurodema thaul. | the effects induced by lead ions on the short-circuit current (scc) and on the potential difference (v) of the toad pleurodema thaul skin were investigated. pb2+ applied to the outer (mucosal) surface increased scc and v and when applied to the inner (serosal) surface decreased both parameters. the stimulatory effect, but not the inhibitory action, was reversible after washout of the metal ion. the amiloride test showed that the increase was due principally to stimulation of the driving potentia ... | 2004 | 15689109 |
| mercuric chloride (hgcl(2)) and methyl mercury (ch(3)hgcl) block sodium transport in the isolated skin of the toad pleurodema thaul. | | 2000 | 11080361 |
| influence of nitric oxide on transepithelial transport in toad skin: effects of cholinergic agents and morphine. | the effects induced by l-arginine (l-arg) on the short-circuit current and potential difference of pleurodema thaul skin were investigated. l-arg, but not d-arg significantly increased the short-circuit current and potential difference when applied to the serosal surface. the effects of l-arg were antagonized by amiloride, ng-nitro-methyl-l-arginine (l-name) and by methylene blue. carbachol and acetylcholine induced significant increases of both electrical parameters of the toad skin. these effe ... | 1996 | 8982659 |
| allozyme variation in populations of pleurodema thaul (lesson, 1826) (anura; leptodactylidae). | genetic variation of 18 loci detected in 13 chilean and one argentinian population of the toad pleurodema thaul are described. seven loci were polymorphic in at least one of the studied populations. the average heterozygosity values observed for locus went from h = 0.00 for the las cardas population to 0.114 in the lautaro locality, with a global average of 5.2%. the genetic similarity values gave an average of 0.875 (range 0.726-1.00). accordingly, similarity values were possible to distinguish ... | 1995 | 8529025 |
| diazepam induces tolerance in the isolated skin of pleurodema thaul. | the effects of the long-term administration of diazepam on the potential difference and short-circuit current of the isolated skin of the toad pleurodema thaul (p. thaul) were investigated. diazepam applied in a concentration range of 4.6 x 10(-6) to 5.2 x 10(-5) m decreased both electrical parameters. this response was unaffected by flumazenil indicating that the action of diazepam is not induced through benzodiazepine receptors. induction of tolerance to diazepam on its observed effects on pot ... | 1995 | 7589190 |
| inhibition of the sodium transport by pentachlorophenol (pcp) in toad skin (pleurodema thaul). | 1. the effects of pentachlorophenol (pcp) were studied in vitro on an active ionic transporting epithelium. ussing's technique was applied on the isolated pleurodema thaul skin. 2. concentrations of pcp in the range 0.003-0.043 mm caused an irreversible dose-dependent inhibition in both the short-circuit current and the potential difference. 3. parameters of an electrical equivalent circuit were calculated applying the isaacon's amiloride test. 4. it was also shown that pcp produced a significan ... | 1992 | 1354113 |
| stimulatory effect of angiotensin ii on the electric properties of the isolated toad skin. | in 1982 we showed that angiotensin ii (agt ii) stimulates the bioelectric properties of the isolated toad skin and that this effect is blocked by pretreatment of the skin with indomethacine [j. b. concha et al., ircs med. sci. 10, 584 (1982)]. ussing's technique and several inhibitors were used to continue this study on the isolated pleurodema thaul skin. serosal agt ii produced a dose-dependent increase in electrical parameters: a maximal concentration of 6 x 10(-6) m agt ii increased potential ... | 1988 | 2899432 |
| determination of the driving force for the sodium pump (ena) and of active and passive conductances (gna and gsh) in isolated toad skin: influence of antidiuretic hormone. | 1. values of the sodium potential (ena), active conductance (gna) and passive conductance (gsh) were measured in the isolated skin of the toad pleurodema thaul placed in an ussing chamber, and isaacson's test was performed with 2,4,6-trieminopyrimidine (tap) and with amiloride. 2. the numerical estimates obtained in the presence of tap were ena 122.85 +/- 15.17 mv, gna 0.493 +/- 0.09 ms/cm2 and gsh 1.145 +/- 0.23 ms/cm2. 3. after exposure to adh these values were as follows: ena 85.76 +/- 12.17 ... | 1987 | 2444489 |
| electrophysiological effects of methyl 3-o-methyl gallate on single muscle fibres. | the electrophysiological changes induced by methyl 3-o-methyl gallate, a substance extracted from crinodendron hookerianum, have been studied on 32 muscle fibres of pleurodema thaul. four concentrations were used: 1 x 10(-5), 2 x 10(-5), 1 x 10(-4), and 2 x 10(-4) mol/l, the results being a reversible dose-dependent reduction of the overshoot and the amplitude of the action potential, a prolongation of the rise and decay times of the spike, as well as a depolarization of the resting membrane pot ... | 1981 | 7291299 |
| effects of a low concentration of ethanol on the potential difference of mucous-secreting glands of the toad pleurodema thaul. | the effect of noradrenaline on the bioelectric activity of the mucous glands of 9 toads was studied by means of intraglandular recording. noradrenaline induced a transient increase in glandular secretion and a simultaneous two-phase increase in the potential difference of the glands. perfusion with 0.043 mm ethanol-ringer's reversibly reduced this response. ouabain, in concentrations which block na+k+-activated atpase, markedly reduced the slow phase of the response of the 'isolated skin to nora ... | 1981 | 7220597 |