Abstract:
:The skin is the largest organ in the body and is a barrier between the internal and external environment. The present study evaluates how PTU, a goitrogen, that is used to treat hyperthyroidism affects the structure and electrical properties of the frog (Xenopus laevis) skin. The results are considered in the context of the two-membrane model established in the seminal work of Ussing and collegues in the 1940s and 1950s. In vitro experiments with skin from Xenopus adults revealed that PTU can act directly on skin and causes a significant increase (p<0.05, One-way ANOVA) in short circuit current (Isc) via an amiloride-insensitive mechanism. Juvenile Xenopus exposed to waterborne PTU (5 mg/L) had a significantly bigger and more active thyroid gland (p<0.01, Student's t-test) than control Xenopus. The bioelectric properties of skin taken from Xenopus juveniles treated with PTU in vivo had a lower Isc, (3.05±0.4, n=13) and Rt (288.2±39.5) than skin from control Xenopus (Isc, 4.19±1.14, n=14; Rt, 343.3±43.3). A histological assessment of skin from PTU treated Xenopus juveniles revealed the epidermis was significantly thicker (p<0.01, Student's t-test) and had a greater number of modified exocrine glands (p<0.01, Student's t-test) in the dermis compared to control skin. Modifications in skin structure are presumably the basis for its changed bioelectric properties and the study highlights a site of action for environmental chemicals which has been largely neglected.
journal_name
Gen Comp Endocrinoljournal_title
General and comparative endocrinologyauthors
Carvalho ES,Fuentes J,Power DMdoi
10.1016/j.ygcen.2011.09.007subject
Has Abstractpub_date
2011-12-01 00:00:00pages
301-8issue
3eissn
0016-6480issn
1095-6840pii
S0016-6480(11)00363-7journal_volume
174pub_type
杂志文章abstract::To design a homologous bioassay for the molt-inhibiting hormone and the crustacean hyperglycemic hormone of the shrimp Penaeus vannamei, the effect of sinus gland homogenate (SGh), in vitro, on ecdysteroid production by Y-organs (YOs), and the effect of the injection of SGh, in vivo, on the glycemia of shrimps have be...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1006/gcen.1996.0092
更新日期:1996-07-01 00:00:00
abstract::Pineal photoreceptor cells produce the neurohormone melatonin, a major "Zeitgeber" of the organism. This compound is involved in the control of development, growth, sexual maturation, and seasonal reproductive cycles. The present study reports that the photosensitive pineal organ and the retina of the trout express a ...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1006/gcen.1994.1008
更新日期:1994-01-01 00:00:00
abstract::Effects of fasting on the growth hormone (GH)--growth hormone receptor (GHR)-insulin-like growth factor-I (IGF-I) axis were characterized in seawater-acclimated tilapia (Oreochromis mossambicus). Fasting for 4 weeks resulted in significant reductions in body weight and specific growth rate. Plasma GH and pituitary GH ...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2006.04.007
更新日期:2006-09-15 00:00:00
abstract::Gonad-stimulating substance (GSS) in starfish is the only known invertebrate peptide hormone responsible for final gamete maturation, rendering it functionally analogous to gonadotropins in vertebrates. In breeding season (stage V), GSS stimulates oocyte maturation to induce 1-methyladenine (1-MeAde) by ovarian follic...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2014.06.003
更新日期:2014-09-01 00:00:00
abstract::Proper functioning of the endocrine stress axis requires communication between the stress axis and other regulatory mechanisms. We here describe an intimate interplay between the stress axis and recombinant human leptin (rhLeptin) in a teleostean fish, the common carp Cyprinus carpio. Restraint stress (by netting up t...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2012.04.004
更新日期:2012-08-01 00:00:00
abstract::Isospecific injections of intercerebral commissure (COM) extracts of L. stagnalis, L. palustris, and L. ovata (Lymnaeidae) and of extracts of COM/mediodorsal bodies complexes (COM/DB) of Bulinus truncatus (Bulinidae) and Biomphalaria glabrata (Planorbidae) induced oviposition in a high percentage of the experimental s...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/0016-6480(83)90164-8
更新日期:1983-10-01 00:00:00
abstract::The effect of corticosteroid hormones in fish are mediated through intracellular receptors that act as ligand-binding transcription factors. Many studies have been devoted to cortisol binding using radiolabeled ligand in fish and allowed characterization of a single class of high affinity binding sites in various tiss...
journal_title:General and comparative endocrinology
pub_type: 杂志文章,评审
doi:10.1016/j.ygcen.2006.01.015
更新日期:2006-05-15 00:00:00
abstract::In the present study we sought to investigate interactions between hypothalamic nitric oxide (NO) and ghrelin signaling on food intake and energy substrate utilization as measured by the respiratory exchange ratio (RER). Guide cannulae were unilaterally implanted in either the arcuate (ArcN) or paraventricular (PVN) n...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2017.05.017
更新日期:2017-09-01 00:00:00
abstract::Prolonged or frequent secretion of adrenal glucocorticoids in response to aversive stimuli can negatively impact reproduction. Because female southern white rhinoceros (Ceratotherium simum simum) reproduce poorly in captivity, we compared fecal corticosterone metabolite concentrations among parous, nulliparous, and ad...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2011.02.010
更新日期:2011-05-01 00:00:00
abstract::Gonadotropin-releasing hormone (GnRH) of vertebrates is now believed to have multiple functions in addition to its role as a hypophysiotropic hormone, as originally defined. Recently, it has been shown that GnRH occurs also in the ascidians, which are considered ancestral chordates. Here the author shows that GnRH ind...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1006/gcen.2001.7728
更新日期:2001-12-01 00:00:00
abstract::Progesterone, 4-androstenedione, testosterone, dihydrotestosterone, 5 alpha-androstane-3 alpha,17 beta-diol (3 alpha-diol), 5 alpha-androstane-3 beta, 17 beta-diol (3 beta-diol), estrone, and estradiol levels were determined by radioimmunoassay in the different lobules of the testis of Salamandra salamandra throughout...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/0016-6480(85)90337-5
更新日期:1985-05-01 00:00:00
abstract::Songbirds possess a specialized network of brain nuclei mediating song learning and production, the song system. In many species, the nuclei in this circuit are larger in volume in males housed on long photoperiods than in males housed on short photoperiods. Exposure to long days initially leads to increases in circul...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1006/gcen.1996.6829
更新日期:1997-02-01 00:00:00
abstract::The hormone leptin has been identified in all vertebrate classes, but its physiological roles in non-mammalian vertebrates are not well defined. To elucidate leptin regulation in energy homeostasis in a teleost fish species, this study compares hypothalamic and pituitary leptin signaling systems in energetically diver...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2016.06.013
更新日期:2016-09-01 00:00:00
abstract::Leptin, a 16-kDa hormone produced by mature adipocytes, has been shown to regulate the hibernation of mammals. In this study, the leptin gene sequences of both hibernating (Rhinolophus ferrumequinum) and non-hibernating (Rousettus leschenaultii) bats were determined, and the leptin proteins from these two different sp...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2010.04.001
更新日期:2010-08-01 00:00:00
abstract::Plasma concentrations of thyroid hormones (TH) were investigated during the extended posthatching developmental period (approximately 11 months) of a semi-altricial bird species, the king penguin (Aptenodytes patagonicus). The first period of growth in summer was marked by a progressive rise in plasma T4 concentration...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2004.02.003
更新日期:2004-05-01 00:00:00
abstract::Wrasse species exhibit a definite daily rhythm in locomotor activity and bury themselves in the sand at the bottom of the ocean at night. It remains unclear how their behavior in locomotor activity is endogenously regulated. The aim of the present study was to clarify the involvement of melatonin and clock genes (Per1...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2012.01.007
更新日期:2012-05-15 00:00:00
abstract::Leach's storm-petrels accumulate large amounts of body mass throughout the nestling period. Approximately 4days before fledging, nestlings weigh 50-100% more than adults. In order to shed this excess mass, nestlings engage in behavioral anorexia, and leave the burrow when they are light enough to fly. During this pref...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2010.07.019
更新日期:2010-10-01 00:00:00
abstract::In this study, parathyroid hormone (PTH) receptor binding was examined in the membrane fraction of the endometrium of the shell gland of laying and nonlaying hens by the use of (125)I-PTH-related peptide (PTHrP) binding assays. Specific (125)I-PTHrP binding was found in the endometrium of the shell gland and increased...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1006/gcen.1999.7395
更新日期:2000-02-01 00:00:00
abstract::Only recently have the cardiac actions of parathyroid hormone and its N-terminal (1-34) fragment (bPTH(1-34] been examined. Parathyroid hormone was found to exert a positive chronotropic effect on the heart tissue of several mammals and one amphibian in vivo and/or in vitro. The purpose of the present study was to exa...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/0016-6480(84)90037-6
更新日期:1984-11-01 00:00:00
abstract::The possum is a seasonally breeding marsupial which gives birth in Queensland from March through to September. To ascertain whether this seasonality in breeding is manifest in the male reproductive system, body weight and plasma testosterone concentrations were examined in five possums. Plasma testosterone concentrati...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/0016-6480(86)90087-0
更新日期:1986-04-01 00:00:00
abstract::Prolactin-like protein (PRL-L; LOC417800) is a homolog of PRL in non-mammalian vertebrates and can act as a functional ligand of PRL receptor (PRLR). Despite its widespread expression in extrapituitary tissues, mechanisms of regulation of PRL-L in the chicken ovary remain unknown. In this study, we first examined PRL-...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2016.10.013
更新日期:2017-01-01 00:00:00
abstract::Dopamine (DA) has a pivotal role in avian prolactin (PRL) secretion, acting centrally through D(1) DA receptors to stimulate PRL secretion by operating through vasoactive intestinal peptide (VIP). DA also inhibits PRL secretion by activating D(2) DA receptors at the pituitary level. This study was designed to investig...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2008.08.002
更新日期:2008-10-01 00:00:00
abstract::Increasing evidence shows that growth hormone (GH) expression is not limited to the pituitary, as it can be produced in many other tissues. It is known that growth hormone (GH) plays a role in the control of reproductive tract development. Acting as an endocrine, paracrine and/or autocrine regulator, GH influences pro...
journal_title:General and comparative endocrinology
pub_type: 杂志文章,评审
doi:10.1016/j.ygcen.2014.02.021
更新日期:2014-07-01 00:00:00
abstract::The capacity for early life environmental stressors to induce programming effects on the endocrine stress response in fish is largely unknown. In this study we determined the effects of high environmental ammonia (HEA) exposure on the stress response in larval zebrafish, assessed the tolerance of embryonic and larval ...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2017.09.024
更新日期:2017-12-01 00:00:00
abstract::The insulin-like growth factor-1 (IGF-1) plays an important role in the regulation of reproductive function. In the present study, we examined the effects of caloric restriction (CR) on the reproductive lifespan in rats and investigated the potential role of IGF-1. After 10 weeks of treatment, we determined the distri...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2011.09.005
更新日期:2011-11-01 00:00:00
abstract::We have previously shown that the somatic growth of barfin flounder, Verasper moseri, was promoted by green light. The present study was undertaken to elucidate whether growth-promoting effect of green light can be observed in other flatfishes and to understand the roles of endocrine systems in green light-induced gro...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2018.11.005
更新日期:2019-01-15 00:00:00
abstract::Flatfishes with more body height after metamorphosis should be better adapted to a benthic lifestyle. In this study, we quantified the changes in body height during metamorphosis in two flatfish species, Paralichthys olivaceus and Platichthys stellatus. The specific pattern of cell proliferation along the dorsal and v...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2016.06.028
更新日期:2016-09-15 00:00:00
abstract::It is now clearly established that the central and peripheral nervous systems have the ability to synthesize de novo steroids referred to as neurosteroids. The major evidence for biosynthesis of neuroactive steroids by nervous tissues is based on the expression of enzymes implicated in the formation of steroids in neu...
journal_title:General and comparative endocrinology
pub_type: 杂志文章,评审
doi:10.1016/j.ygcen.2015.05.014
更新日期:2016-02-01 00:00:00
abstract::Pancreatic polypeptide (PP) has been isolated from pancreatic extracts of the herring gull (Larus argentatus) using a radioimmunoassay employing an antiserum (PP 221), generated to the conserved C-terminal hexapeptide amide of mammalian PP. Gel permeation and reverse-phase HPLC fractionation of crude pancreatic extrac...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1006/gcen.1994.1029
更新日期:1994-02-01 00:00:00
abstract::We investigated the effect of several potential carbohydrate secretagogues, amino acids, a ketoacid, and potassium chloride on insulin, glucagon, and somatostatin release from the in vitro perfused Brockmann body of channel catfish (Ictalurus punctatus). Mannose (15 mM) stimulated the release of insulin and somatostat...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/0016-6480(87)90120-1
更新日期:1987-03-01 00:00:00