abstract：:In order to investigate the ontogeny of steroid secretions during the juvenile phase, sexual steroids were extracted and assayed after chromatographic separation in the gonads and plasma of male and female salamanders Salamandra salamandra L. at three characteristic postlarval stages. All specimens were collected in t...

journal_title：General and comparative endocrinology

authors： Garnier DH,Joly J

更新日期：1991-01-01 00:00:00

abstract：:The ability of hormones to bind to their functional receptors on turtle (Pseudemys scripta) endocrine target tissues in the cold was tested by treating tissues with secretagogues at low temperatures (5-15 degrees) and then following subsequent target stimulation in the absence of secretagogue at a warm temperature (28...

journal_title：General and comparative endocrinology

authors： Licht P,Pavgi S,Denver RJ

更新日期：1990-12-01 00:00:00

abstract：:Attractiveness in adult females of Calliphora vomitoria is correlated with ovarian development and there is a marked increase during the previtellogenic and vitellogenic periods. The development of attractiveness may result from the combined actions of ecdysteroids and juvenile hormone. A rise in total hydrocarbons pa...

journal_title：General and comparative endocrinology

authors： Trabalon M,Campan M,Porcheron P,Clement JL,Baehr JC,Moriniere M,Joulie C

更新日期：1990-11-01 00:00:00

abstract：:It has been suggested that the functional diversity of growth hormone (GH) is related to its molecular complexity. Here we report a characterization of charge and mass variants of chicken growth hormone (cGH) through a variety of electrophoretic systems [nondenaturing (ND-PAGE), denaturing (SDS-PAGE), under reducing a...

journal_title：General and comparative endocrinology

authors： Arámburo C,Montiel JL,Perera G,Navarrete S,Sánchez R

更新日期：1990-10-01 00:00:00

abstract：:Dopamine receptors in the pituitary of the African catfish, Clarias gariepinus, were characterized using [3H]spiperone as radioligand. Specific binding of [3H]spiperone to pituitary membranes reached equilibrium within 60 min of incubation. The binding of the radioligand was tissue specific since the amount of binding...

journal_title：General and comparative endocrinology

authors： Van Asselt LA,Goos HJ,De Leeuw R,Peter RE,Hol EM,Wassenberg FP,Van Oordt PG

更新日期：1990-10-01 00:00:00

abstract：:An immunohistological analysis of the chromaffin cell system of the American eel revealed the presence of tyrosine hydroxylase (TH) and dopamine-beta-hydroxylase (DBH) in all cells. However, phenylethanolamine-N-methyltransferase (PNMT) was seen only in a fraction of the chromaffin cells. This suggests the presence of...

journal_title：General and comparative endocrinology

authors： Hathaway CB,Epple A

更新日期：1990-09-01 00:00:00

abstract：:Male, dark-eyed juncos, Junco hyemalis, were held in captivity under conditions simulating winter temperature and photoperiod. Birds were administered corticosterone (B), metapyrone (MET), or control (empty) implants in silastic tubing. B implants resulted in higher plasma levels of B, especially on the first day foll...

journal_title：General and comparative endocrinology

authors： Gray JM,Yarian D,Ramenofsky M

更新日期：1990-09-01 00:00:00

abstract：:In rainbow trout, a variable in vivo pituitary sensitivity to GnRH has been previously observed, depending on the stage of oogenesis. The purpose of the present work was to study, in vitro, the role of oestradiol (E2) and 17 alpha-hydroxy,20 beta-dihydroprogesterone (17 alpha 20 beta P), respectively, involved in vite...

journal_title：General and comparative endocrinology

authors： Weil C,Marcuzzi O

更新日期：1990-09-01 00:00:00

abstract：:Effects of growth hormone (GH) on the synthesis of mucopolysaccharide by ceratobranchial cartilages of the Japanese eel, Anguilla japonica, were examined by monitoring the in vitro uptake of [35S]sulfate. The [35S]sulfate uptake decreased rapidly to one-third of the initial level during the first 3 days after hypophys...

journal_title：General and comparative endocrinology

authors： Duan CM,Inui Y

更新日期：1990-08-01 00:00:00

abstract：:The pattern and kinetics of degradation of native salmon gonadotropin-releasing hormone (sGnRH) and mammalian leuteinizing hormone-releasing hormone (LHRH) by pituitary bound enzymes were studied in the gilthead seabream, Sparus aurata. sGnRH and LHRH were incubated for different periods of time with membrane or cytos...

journal_title：General and comparative endocrinology

authors： Goren A,Zohar Y,Fridkin M,Elhanati E,Koch Y

更新日期：1990-08-01 00:00:00

abstract：:The possible physiological role of a putative testicular gonadotropin-releasing hormone (GnRH)-like material was studied in the frog, Rana esculenta. We have investigated (a) changes of mitotic index (MI) of primary spermatogonia (SPG) in GnRH agonist (GnRH-Ag)-treated testes in vitro; (b) changes of androgen concentr...

journal_title：General and comparative endocrinology

authors： Di Matteo L,Minucci S,Fasano S,D'Antonio M,Pierantoni R,Chieffi G

更新日期：1990-07-01 00:00:00

abstract：:Neurohypophysial hormones in mammals are synthesized by the ovary and may influence reproductive function. Although arginine vasotocin (AVT) can induce premature oviposition in chickens, the gonadal content of AVT or mesotocin (MT) has not been examined in this species. Ovarian follicles were removed 2 hr before ovipo...

journal_title：General and comparative endocrinology

authors： Saito N,Kinzler S,Koike TI

更新日期：1990-07-01 00:00:00

abstract：:The present work describes the neuroanatomical distribution of the immunoreactive luteinizing hormone-releasing hormone (ir-LHRH) system in the brain of adult male and female, castrated male and developing Rana esculenta. No obvious sex differences in the distribution pattern of ir-LHRH were observed. Immunoreactive n...

journal_title：General and comparative endocrinology

authors： Rastogi RK,Di Meglio M,Iela L

更新日期：1990-06-01 00:00:00

abstract：:A specific polyclonal antiserum directed against the somatostatin-28(1-14) of vertebrates was applied to sections of the planarians Dugesia lugubris and Dendrocoelum lacteum. This made it possible to reveal nerve cells and processes specifically both in cerebral ganglia and in ventral nerve cords. The phylogenetic imp...

journal_title：General and comparative endocrinology

authors： Bautz A,Richoux JP,Schilt J

更新日期：1990-06-01 00:00:00

abstract：:Intraperitoneal injection of rainbow trout (Salmo gairdneri) with 0.4 microgram/g of human growth hormone (hGH) increased plasma levels of 3,5,3'-triiodo-L-thyronine (T3) and Vmax of the hepatic microsomal 5'-monodeiodinase enzyme (5'D) that converts thyroxine (T4) to T3, with no effect on Km or plasma T4 levels. A do...

journal_title：General and comparative endocrinology

authors： MacLatchy DL,Eales JG

更新日期：1990-05-01 00:00:00

abstract：:The activities of oxidative enzymes of hepatic mitochondria of Anabas testudineus increased following exogenous administration of hydrocortisone and corticosterone. The inhibitors of protein synthesis prevented the hormone-mediated increase of hepatic enzymes, suggesting that corticosteroids regulate the oxidative met...

journal_title：General and comparative endocrinology

authors： Ignatius J,Oommen OV

更新日期：1990-05-01 00:00:00

abstract：:The complete amino acid sequences of alpha subunits of chum salmon (Oncorhynchus keta) gonadotropins (GTHs), GTH I and GTH II, were determined. Subunits were separated by reversed-phase high-performance liquid chromatography. Two alpha subunits, I alpha 1 and I alpha 2, were obtained from GTH I, whereas only one alpha...

journal_title：General and comparative endocrinology

authors： Itoh H,Suzuki K,Kawauchi H

更新日期：1990-04-01 00:00:00

abstract：:A rapid and sensitive heterologous enzyme-linked immunosorbent assay (ELISA) was developed to measure rainbow trout maturational gonadotropin. Purified salmon maturational gonadotropin (sGtH II) was used as reference hormone. Optimization of the procedure was performed by using an anti-beta sGtH serum. Two procedures ...

journal_title：General and comparative endocrinology

authors： Salbert G,Bailhache T,Zohar Y,Breton B,Jego P

更新日期：1990-04-01 00:00:00

abstract：:The hypothesis that vasoactive intestinal peptide (VIP) functions as a hypothalamic prolactin (PRL)-releasing peptide in the turkey was tested by determining the effects of hypothalamic VIP immunoneutralization and pituitary VIP receptor blockade on hypothalamic extract (HE)-induced PRL secretion from dispersed anteri...

journal_title：General and comparative endocrinology

authors： el Halawani ME,Silsby JL,Mauro LJ

更新日期：1990-04-01 00:00:00

abstract：:During the previtellogenic development of mosquito fat body cells, the nucleolus, the organelle responsible for producing ribosomes, enlarges threefold, reaching maximal size between 2 and 3 days after eclosion. The granular component of the nucleolus containing ribosomal precursors increases considerably as well. The...

journal_title：General and comparative endocrinology

authors： Raikhel AS,Lea AO

更新日期：1990-03-01 00:00:00

abstract：:In a series of experiments, the effect of cortisol on the ability of rainbow trout (Salmo gairdneri) ovarian follicles to secrete sex steroids in vitro was investigated. The basal rate of secretion of sex steroids (oestradiol and testosterone) was suppressed in a dose-dependent manner by the addition of cortisol to th...

journal_title：General and comparative endocrinology

authors： Carragher JF,Sumpter JP

更新日期：1990-03-01 00:00:00

abstract：:The rostral pars distalis (RPD), containing mainly prolactin (PRL)-secreting cells, of the pituitary from immature and mature tilapia was incubated for 16 hr at 27 degrees in hypoosmotic medium (300 mOsm/kg) in the presence (10(-8) and 10(-11) M) or absence of the human GnRH-associated peptide (GAP) molecule, a potent...

journal_title：General and comparative endocrinology

authors： Planas J,Bern HA,Millar RP

更新日期：1990-03-01 00:00:00

abstract：:The possibility that the tonic secretion of luteinizing hormone (LH) and chicken luteinizing hormone-releasing hormone I (LHRH-I) is regulated by an inhibitory action of endogenous opioid peptides was investigated in cockerels using the opiate receptor antagonist, naloxone. Baseline concentrations of plasma LH in the ...

journal_title：General and comparative endocrinology

authors： Lal P,Sharp PJ,Dunn IC,Talbot RT

更新日期：1990-02-01 00:00:00

abstract：:This study investigated the role of gonadotrophin and steroids in the induction of in vitro oocyte maturation in dab (Limanda limanda) and plaice (Pleuronectes platessa), two marine flatfish (Pleuronectiformes) in which the oocytes mature and ovulate in groups (or batches). Clusters of folliculated oocytes were incuba...

journal_title：General and comparative endocrinology

authors： Canario AV,Scott AP

更新日期：1990-02-01 00:00:00

abstract：:A detailed study was made of sex differentiation in three anteroposteriorly distributed body regions of the long gonadal fold in young Pacific hagfish (Eptatretus stouti) from 12.4 to 45 cm in length. In general, the posterior region, adjacent to the cloaca, remained undifferentiated, and only in specimens more than 2...

journal_title：General and comparative endocrinology

authors： Gorbman A

更新日期：1990-02-01 00:00:00

abstract：:Two types of somatostatin (SST 14)-immunoreactive cells are identified by immunogold staining in the Lowicryl-embedded principal islet of Sparus auratus: D1 cells, having large moderate to low electron dense granules, located between A cells in the islet periphery and D2 cells, containing smaller electron-dense granul...

journal_title：General and comparative endocrinology

authors： Abad ME,Lozano MT,Taverne-Thiele JJ,Rombout JH

更新日期：1990-01-01 00:00:00

abstract：:High-affinity, limited-capacity, 3,5,3'-triiodo-L-thyronine (T3)-binding sites were established by in vitro saturation analysis in cell nuclei of the pituitary gland of arctic charr. The sites were extracted from the purified nuclei using 0.4 M NaCl and incubated with [125I]T3 in the presence of 0.2 M NaCl. T3 saturab...

journal_title：General and comparative endocrinology

authors： Bres O,Eales JG

更新日期：1990-01-01 00:00:00

abstract：:In mammals, a well-documented inverse relationship exists between oral salt intake and plasma renin activity (PRA). We carried out this study to determine if a similar relationship exists in the freshwater turtle Pseudemys scripta. Three groups of turtles (N = 8 for each group) were fed different amounts of salt disso...

journal_title：General and comparative endocrinology

authors： Stephens GA,Hauben D

更新日期：1989-12-01 00:00:00

abstract：:The parathyroid glands of chickens were autotransplanted and the return of parathyroid function following transplantation was determined. Parathyroidectomy (PTX) resulted in a marked hypocalcemia (5.2 +/- 0.2 mg/dl) 4 hr following PTX. Plasma calcium (PCa) had declined to 4.3 +/- 0.2 mg/dl 24 hr after PTX. Parathyroid...

journal_title：General and comparative endocrinology

authors： Cole JA,Forte LR,Thorne PK,Poelling RE,Krause WJ

更新日期：1989-12-01 00:00:00

abstract：:A reliable and rapid technique for the measurement of estradiol-17 beta, testosterone, progesterone, 17 alpha-hydroxyprogesterone, 17 alpha,20 beta-dihydroxy-4-pregnen-3-one, and cortisol by reverse-phase high-performance liquid chromatography and radioimmunoassay in single female goldfish serum samples of 50 microlit...

journal_title：General and comparative endocrinology

authors： Venkatesh B,Tan CH,Lam TJ

更新日期：1989-12-01 00:00:00

abstract：:Serum levels of prolactin were determined in nonbreeding male and female canvasbacks (Aythya valisineria) from mid-April to late June to evaluate the temporal changes occurring during spring. During this time interval, serum prolactin levels increased 1.5- to 2-fold in both males and nonlaying females (P less than 0.0...

journal_title：General and comparative endocrinology

authors： Bluhm CK,Phillips RE,Burke WH

更新日期：1989-11-01 00:00:00

abstract：:Homogenates of ovaria as well as testes from the locust Locusta migratoria were analyzed for the presence of pregnenolone, testosterone, and estradiol by gas chromatography followed by mass spectrometry. Selected ion monitoring analyses revealed that the molecular ion and two characteristic fragment ions of pregnenolo...

journal_title：General and comparative endocrinology

authors： Novak FJ,Lambert JG

更新日期：1989-10-01 00:00:00

abstract：:Male bluegill (Lepomis macrochirus) display a complex reproductive behavior involving two alternative life history pathways: delay of sexual maturation to become "parentals" or precocious maturation as "cuckolders." The purpose of our study was to investigate the association of two androgens, 11-ketotestosterone (11KT...

journal_title：General and comparative endocrinology

authors： Kindler PM,Philipp DP,Gross MR,Bahr JM

更新日期：1989-09-01 00:00:00

abstract：:The effect of a gonadotropin-releasing hormone analog (GnRHA, HOE766) was studied in hypophysectomized elasmobranch fish Torpedo marmorata and T. ocellata. In addition, estradiol (E2) effects were studied in intact and hypophysectomized (HPX) animals. Plasma androgen concentrations were measured 2 or 6 hr after GnRHA ...

journal_title：General and comparative endocrinology

authors： Fasano S,Pierantoni R,Minucci S,Di Matteo L,D'Antonio M,Chieffi G

更新日期：1989-09-01 00:00:00

abstract：:Ecdysteroid production by the prothoracic glands of the tobacco hornworm, Manduca sexta was found to be under feedback control by the ecdysteroids in hemolymph using both culture in vivo in diapausing pupae lacking the brain-corpora cardiaca-corpora allata complex and the prothoracic glands and culture in vitro. Proth...

journal_title：General and comparative endocrinology

authors： Sakurai S,Williams CM

更新日期：1989-08-01 00:00:00

abstract：:In the present study, we have localized for the first time beta-endorphin (beta-EP)-like material in the adult and larval urodele and anuran tissues using immunohistochemical techniques. In the adult Notophthalmus viridescens and Ambystoma mexicanum, strong immunoreactivity to beta-EP antisera was observed in the regi...

journal_title：General and comparative endocrinology

authors： Vethamany-Globus S

更新日期：1989-08-01 00:00:00

abstract：:Plasma progesterone concentrations were measured every 2 or 3 days in eastern quoll, Dasyurus viverrinus, during pregnancy (20.5 +/- 0.8 days, n = 6, mean +/- SEM) and the estrous cycle (37.5 +/- 0.7 days, n = 20, mean +/- SEM). The pattern was not apparently different between the two reproductive states. There was a ...

journal_title：General and comparative endocrinology

authors： Hinds LA

更新日期：1989-07-01 00:00:00

abstract：:This study directly tested the hypothesis that 17 alpha,20 beta-dihydroxy-4-pregnen-3-one (17,20 beta-P) is a goldfish preovulatory pheromone (pheromone released at peak levels during oocyte final maturation) which increases blood gonadotropin (GtH) and milt volume in males. During spontaneous ovulation, GtH and 17,20...

journal_title：General and comparative endocrinology

authors： Stacey NE,Sorensen PW,Van der Kraak GJ,Dulka JG

更新日期：1989-07-01 00:00:00

abstract：:Bovine thyroid-stimulating hormone (TSH) was microinjected (0.2 microliter/fish) into prometamorphic flounder larvae and the effects on metamorphosis as well as the tissue thyroxine (T4) and triiodothyronine (T3) levels were studied. After a single injection of TSH (5 mIU/g), the tissue T4 concentration increased mark...

journal_title：General and comparative endocrinology

authors： Inui Y,Tagawa M,Miwa S,Hirano T

更新日期：1989-06-01 00:00:00

abstract：:Gonadotropin (GTH) secretion is known to be under inhibitory dopaminergic control in several species of fish. To investigate whether this is also the case in the Atlantic croaker (Micropogonias undulatus), juvenile and adult croaker were treated with a gonadotropin-releasing hormone analog (des-Gly10D-Ala6Pro9 n ethyl...

journal_title：General and comparative endocrinology

authors： Copeland PA,Thomas P

更新日期：1989-06-01 00:00:00