abstract：:In the summer of 1991 (late May to early September), I measured seasonal levels of plasma androgens in two species of plethodontid salamanders to assess the temporal relationship of elevated plasma androgen levels with spermatogenic events and with sexual behavior. In both species, spermatogenesis occurs in the spring...

journal_title：General and comparative endocrinology

authors： Woodley SK

更新日期：1994-11-01 00:00:00

abstract：:The activity of the enzyme steroid 5 alpha-reductase in Harderian glands of adult syrian hamsters was assessed by measuring the conversion of testosterone (T) to 5 alpha-dihydrotestosterone (DHT). The optimal conditions for this reaction were determined in vitro using whole gland homogenates and [3H]testosterone as su...

journal_title：General and comparative endocrinology

authors： Vilchis F,Enriquez J,Queipo G,Pérez-Palacios G,Chávez B

更新日期：1994-11-01 00:00:00

abstract：:Regression of the müllerian ducts in mammals and birds is caused by the testicular hormone, müllerian inhibiting substance (MIS), which is produced for an extended period of time after testicular differentiation. Because it is present long after the ducts regress, it has been proposed to have additional effects other ...

journal_title：General and comparative endocrinology

authors： Austin HB

更新日期：1994-10-01 00:00:00

abstract：:The objective of this study was to examine if RU486, a corticosteroid antagonist, modified hepatocyte metabolism and blocked the metabolic effects of exogenously administered cortisol in rainbow trout (Oncorhynchus mykiss). The fish were given a single intraperitoneal implant of either coconut oil alone or coconut oil...

journal_title：General and comparative endocrinology

authors： Vijayan MM,Reddy PK,Leatherland JF,Moon TW

更新日期：1994-10-01 00:00:00

abstract：:Plasma prolactin (PRL) and vitellogenin (VTG) concentrations were determined during the annual reproductive cycle of the newt Triturus carnifex Laur. Plasma PRL was measured by a radioimmunoassay using purified newt (Cynops pyrrogaster) PRL as standard and radioligand and its antibodies. Using ELISA, plasma VTG titers...

journal_title：General and comparative endocrinology

authors： Mosconi G,Yamamoto K,Kikuyama S,Carnevali O,Mancuso A,Vellano C

更新日期：1994-09-01 00:00:00

abstract：:A conglomerate of 8-12 neurons in the medulla externa of the crayfish eyestalk was explored in their reaction to a polyclonal antibody against the tyrosinated octapeptide Red Pigment Concentrating Hormone (Tyr-RPCH). These are large neurons with diameters within a range of 33-43 microns and they were all positively st...

journal_title：General and comparative endocrinology

authors： Preciado M,Tsutsumi V,Aréchiga H

更新日期：1994-09-01 00:00:00

abstract：:Vitellogenesis in tuatara (Sphenodon punctatus) on Stephens Island, New Zealand, at the southern (coolest) end of the geographical range of this species involves a prolonged period of about 3 years of the average 4-year reproductive cycle. These studies used a semiquantitative electrophoretic assay for vitellogenin (V...

journal_title：General and comparative endocrinology

authors： Brown MA,Cree A,Daugherty CH,Dawkins BP,Chambers GK

更新日期：1994-08-01 00:00:00

abstract：:Urinary excretion of the thyroid hormones (TH) L-thyroxine (T4), and 3,5,3'-triiodo-L-thyronine (T3) and their derivatives was studied in urinary-catheterized rainbow trout (mean wt. 227 g) fasted for 2 days under a 12-hr L:12-hr D photocycle in running water (12 degrees). Catheterized trout were intracardiac-injected...

journal_title：General and comparative endocrinology

authors： Parry JE,Zhang C,Eales JG

更新日期：1994-08-01 00:00:00

abstract：:The occurrence of myoendocrine-like cells investing the ampullar draining region of Malpighian tubules and neighboring midgut and hindgut regions of the ant Formica polyctena is reported. These striated muscle cells show small electron-dense endocrine-like granules (130 +/- 0.95 nm) in addition to myofilaments and ord...

journal_title：General and comparative endocrinology

authors： Garayoa M,Villaro AC,Sesma P

更新日期：1994-07-01 00:00:00

abstract：:Follicle-stimulating hormone (FSH) stimulates aromatase activity of immature rat Sertoli cells cultured in vitro in the presence of an androgen substrate, a phenomenon that can be used to measure FSH bioactivity. This paper analyzes the effects of sera from various animal species on both aromatase activity and morphol...

journal_title：General and comparative endocrinology

authors： Simoni M,Schuhmann B,Weinbauer GF

更新日期：1994-07-01 00:00:00

abstract：:Unlike mammals, the goldfish is unique in having dopamine (DA) D1 receptors in the anterior pituitary. In this species, DA stimulates growth hormone (GH) release via D1 receptors coupled to the cAMP-dependent pathway. To further examine the postreceptor mechanisms of this novel pituitary DA D1 system, the role of extr...

journal_title：General and comparative endocrinology

authors： Wong AO,Van Goor F,Chang JP

更新日期：1994-06-01 00:00:00

abstract：:Four monoclonal antibodies (MA-5, MA-10, MA-20, and MA-51) and one polyclonal antibody (ARS-2) against human insulin receptor were used to immunoprecipitate the insulin receptor from several species which had been photolabeled with N epsilon B29-monoazido-benzoyl-[125I]iodoinsulin. All four monoclonal antibodies immun...

journal_title：General and comparative endocrinology

authors： Tong ZQ,Jack E,Moule M,Goldfine ID,Yip CC

更新日期：1994-06-01 00:00:00

abstract：:Using frog ovarian follicles in vitro we assessed the role of the theca/epithelium (THEP) layer and granulosa cells in the production of steroids. The THEP layer and granulosa cell-enclosed oocytes (GCEOs) were separated from ovarian follicles of the frog, Rana nigromaculata, by microdissection. Intact follicles (IFs)...

journal_title：General and comparative endocrinology

authors： Kwon HB,Ahn RS

更新日期：1994-05-01 00:00:00

abstract：:Cytosol and crude nuclear extracts of brains from female Diploptera punctata were found to contain a juvenile hormone-binding protein. The binding kinetics of the cytosol and nuclear juvenile hormone-binding proteins toward racemic [3H]JH III were determined using the dextran-coated charcoal assay. Both proteins show ...

journal_title：General and comparative endocrinology

authors： King LE,Zhang J,Tobe SS

更新日期：1994-04-01 00:00:00

abstract：:Using purified thyroglobulin (TG) of Rana catesbeiana and its antisera, a specific double-antibody radioimmunoassay (RIA) was developed. Serum TG content was measured in tadpoles, froglets, and adult frogs by RIA. Serum TG increased during pre- and prometamorphosis and reached a peak of 476.9 +/- 29.1 ng/ml at the cli...

journal_title：General and comparative endocrinology

authors： Suzuki S,Fujikura K

更新日期：1994-04-01 00:00:00

abstract：:The regulation of rainbow trout prolactin (PRL) cells by hypothalamic and humoral factors has been investigated. PRL cell activity was assessed using acid gel electrophoresis to measure PRL release in vitro and image analysis to measure PRL cell nuclear area, an index of synthetic activity. 17 beta-oestradiol stimulat...

journal_title：General and comparative endocrinology

authors： Williams AJ,Wigham T

更新日期：1994-03-01 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

authors： Barton CL,Shaw C,Halton DW,Thim L

更新日期：1994-02-01 00:00:00

abstract：:The in vitro effects of salmon gonadotropin-releasing hormone (sGnRH), substance P (SP), and their antagonists on prostaglandin F2 alpha (PGF2 alpha), prostaglandin E2 (PGE2), progesterone, androgens, and estradiol-17 beta release by follicles and corpus luteum (CL) of the oviparous lizard, Podarcis sicula sicula, wer...

journal_title：General and comparative endocrinology

authors： Gobbetti A,Zerani M,Di Fiore MM

更新日期：1994-02-01 00:00:00

abstract：:Steelhead and hybrid trout (rainbow trout male, steelhead female) presmolts and smolts, Oncorhynchus mykiss, exposed to 30/1000 seawater (SW) for 24 hr manifested progressively lower plasma sodium values from December to May. The increase in plasma sodium after 24 hr in SW diminished significantly after March, with th...

journal_title：General and comparative endocrinology

authors： McLeese JM,Johnsson J,Huntley FM,Clarke WC,Weisbart M

更新日期：1994-01-01 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

authors： Begay V,Valotaire Y,Ravault JP,Collin JP,Falcon J

更新日期：1994-01-01 00:00:00

abstract：:The role of the pituitary in regulating interrenal activity in coho salmon (Oncorhynchus kisutch) was examined using short- (1 week) or long- (10 week) term hypophysectomized (Hx) animals. In experiments in which Hx animals were injected with ovine growth hormone (oGH), triiodothyronine, or vehicle, plasma cortisol wa...

journal_title：General and comparative endocrinology

authors： Young G

更新日期：1993-12-01 00:00:00

abstract：:Plasma and gonadal levels of several gonadal steroids (testosterone, 11-ketotestosterone, androstenedione, 11 beta-hydroxyandrostenedione, 17 beta-estradiol, and estrone) were measured by RIA in the protandrous seabass, Lates calcarifer, throughout an annual reproductive cycle. Twenty to 25 fish were killed every mont...

journal_title：General and comparative endocrinology

authors： Guiguen Y,Jalabert B,Thouard E,Fostier A

更新日期：1993-12-01 00:00:00

abstract：:Using antibodies to the amino-terminal region of human parathyroid hormone-related protein (PTHrP) we have demonstrated PTHrP immunoreactivity in pituitaries and plasma of the sea bream (Sparus aurata). Pituitary cells at two distinct locations contained immunodetectable PTHrP; an anterior group in the rostral pars di...

journal_title：General and comparative endocrinology

authors： Danks JA,Devlin AJ,Ho PM,Diefenbach-Jagger H,Power DM,Canario A,Martin TJ,Ingleton PM

更新日期：1993-11-01 00:00:00

abstract：:The total cortisol content in tilapia was 55 pg immediately following fertilization, then decreased abruptly and maintained a lower level of 10-20 pg until hatching; after hatching the cortisol content increased to 50 pg by the 7th day. Fertilized eggs were incubated in either 32% saltwater or fresh water and sampled ...

journal_title：General and comparative endocrinology

authors： Hwang PP,Wu SM

更新日期：1993-11-01 00:00:00

abstract：:The cell types within the endocrine pancreatic tissue and anterior intestine of larvae and juveniles of representatives of the two southern-hemisphere families (Mordaciidae and Geotriidae) were compared, using immunohistochemistry and antisera against insulin (lamprey, bovine), two somatostatins (SST-14, -34), two PP-...

journal_title：General and comparative endocrinology

authors： Youson JH,Potter IC

更新日期：1993-11-01 00:00:00

abstract：:The presence and distribution of cholecystokinin (CCK)/gastrin-like immunoreactivity (IR) was examined in the goldfish pituitary. Intense CCK/gastrin-like IR was consistently observed within fibers of the proximal pars distalis (PD), with fewer IR fibers localized in the rostral PD. Within the proximal PD CCK/gastrin-...

journal_title：General and comparative endocrinology

authors： Himick BA,Golosinski AA,Jonsson AC,Peter RE

更新日期：1993-10-01 00:00:00

abstract：:The rainbow trout (Oncorhynchus mykiss) ovarian gonadotropin (GTH II) receptor was solubilized by extraction with the nonionic detergent 1% Triton X-100 in the presence of 20% glycerol. The hormone-binding characteristics of the soluble receptors were similar to those of membrane-bound receptors: the Scatchard plot of...

journal_title：General and comparative endocrinology

authors： Quesnel H,Breton B

更新日期：1993-09-01 00:00:00

abstract：:Plasma profiles of several gonadal steroids and cortisol were examined in a field population of the protandrous, sex-changing anemonefish Amphiprion melanopus to elucidate potential roles of these hormones in gonadal sex change. Sex change was experimentally induced in males by removal of their dominant female pair ma...

journal_title：General and comparative endocrinology

authors： Godwin JR,Thomas P

更新日期：1993-08-01 00:00:00

abstract：:Big dynorphin (prodynorphin 209-240), dynorphin A (prodynorphin 209-225), dynorphin B (prodynorphin 228-240), beta-endorphin (beta-lipotrophin 61-90), or Met-enkephalin, each infused into the third ventricle, were tested for their effect on PRL release in the anesthetized turkey hen. Laying hens that received big dyno...

journal_title：General and comparative endocrinology

authors： Youngren OM,Silsby JL,Phillips RE,el Halawani ME

更新日期：1993-08-01 00:00:00

abstract：:This study was designed to examine the relationship among ovulation rate, inhibin alpha-subunit gene expression, and plasma immunoreactive inhibin levels between hens laying at a high ovulation rate and hens laying at a low ovulation rate. A porcine inhibin alpha-subunit cDNA was used to examine the expression of inhi...

journal_title：General and comparative endocrinology

authors： Wang SY,Johnson PA

更新日期：1993-07-01 00:00:00

abstract：:1,25-dihydroxyvitamin D3 (1,25(OH)2D3), the hormonally active metabolite of vitamin D3 interacts with its nuclear/cytosolic receptor to induce biological responses in target tissues. Naked mole rats appear to be naturally deficient in vitamin D. The questions arise whether these animals possess the 1,25(OH)2D3 recepto...

journal_title：General and comparative endocrinology

authors： Sergeev IN,Buffenstein R,Pettifor JM

更新日期：1993-06-01 00:00:00

abstract：:Uptake of L-thyroxine (T4) by isolated trout hepatocytes was characterized after 1-min incubation of cells in a Hanks' balanced salts medium containing glucose and [125I]T4. Centrifugation through silicone oil and glycine buffer (pH 10.5) was used to separate cells from the medium and minimize extracellular binding of...

journal_title：General and comparative endocrinology

authors： Riley WW Jr,Eales JG

更新日期：1993-04-01 00:00:00

abstract：:Methyl farnesoate (MF) stimulation of ecdysteroid secretion by Y-organs of the crab, Cancer magister, is demonstrated. Isolated Y-organs that were incubated with a mandibular organ (MO) secreted significantly higher levels of ecdysteroids into the medium when compared to those incubated in the absence of a MO. MOs sec...

journal_title：General and comparative endocrinology

authors： Tamone SL,Chang ES

更新日期：1993-03-01 00:00:00

abstract：:Renal actions of arginine vasotocin (AVT) and atrial natriuretic peptide (ANP) in teleosts are poorly defined. Administration of these hormones changes renal function, largely explained by systemic vascular effects. The present experiments examine the potential direct action of these hormones on the teleost nephron. T...

journal_title：General and comparative endocrinology

authors： Perrott MN,Sainsbury RJ,Balment RJ

更新日期：1993-03-01 00:00:00

abstract：:We have examined the effect of ambient water temperature on the ability of juvenile rainbow trout to respond to estradiol (E2) injection with vitellogenin (Vg) synthesis. Vg appeared in serum within 24 hr of E2 injection in fish kept at 15 degrees and rose to 70 mg/ml over a 10-day treatment period during which four i...

journal_title：General and comparative endocrinology

authors： Mackay ME,Lazier CB

更新日期：1993-02-01 00:00:00

abstract：:Naked mole rats seem to be naturally deficient in cholecalciferol yet exhibit net calcium and inorganic phosphorus absorption efficiencies that approach a physiological maximum (i.e., exceed 94%). Oral supplementation with cholecalciferol therefore does not markedly enhance the efficiency of gastrointestinal absorptio...

journal_title：General and comparative endocrinology

authors： Yahav S,Buffenstein R,Pettifor JM

更新日期：1993-01-01 00:00:00

abstract：:The effects of salmon gonadotropin-releasing hormone (sGnRH) and the superactive agonist [D-Arg6, Pro9NEt]-sGnRH (sGnRH-A) on growth hormone (GH) and gonadotropin (GtH) release were examined using a perifusion system for pituitary fragments of the common carp (Cyprinus carpio). Perifusion of 2-min pulses of different ...

journal_title：General and comparative endocrinology

authors： Lin XW,Lin HR,Peter RE

更新日期：1993-01-01 00:00:00

abstract：:Oligonucleotide probes were synthesized for the mRNAs of a pair of tilapia prolactins (tPRL177 and tPRL188) and growth hormone (tGH) based on cDNAs for the hormones of Oreochromis niloticus and amino acid sequences for the hormones of O. mossambicus. The three 45mer probes were labeled with 35S for hybridization studi...

journal_title：General and comparative endocrinology

authors： Nishioka RS,de Jesus EG,Hyodo S

更新日期：1993-01-01 00:00:00

abstract：:The effects of PGE1, PGE2, PGF2 alpha (2 micrograms/ml), and forskolin (10 microM) on follicle contraction of brook trout (salvelinus fontinalis) were studied by measuring the weight loss of punctured follicles during in vitro incubation. PGE1, PGE2, and forskolin significantly inhibited spontaneous contraction of fol...

journal_title：General and comparative endocrinology

authors： Hsu SY,Goetz FW

更新日期：1992-12-01 00:00:00

abstract：:An androgen-binding activity has been identified in nuclear extracts of the testis of the frog, Rana esculenta. A single class of high affinity (Kd = 2.5 +/- 0.6 x 10(-9) M), low-capacity binding sites was found. The binding was specific for androgens; 17 beta-estradiol displaced [3H]testosterone with an ID50 of 0.1 m...

journal_title：General and comparative endocrinology

authors： Paolucci M,D'Antonio M,Pierantoni R

更新日期：1992-12-01 00:00:00