Abstract：
:Profiles of testosterone, 11-ketotestosterone, androstenedione, and estradiol were determined by RIA, and immunocytochemical techniques were employed to identify gonadotropin (GTH) I and II and gonadotropin releasing hormone (GnRH) in monosex and mixed sex populations of rainbow trout from 1 to 126 days postfertilization (dpf). Steroid levels were relatively high at 1 dpf and declined until 25 dpf. At 30 and 48 dpf (hatching) steroid levels increased slightly before they fell by 78 dpf and remained relatively constant thereafter. Trends toward differences in steroid content between males and females became evident around the time gonadal differentiation was histologically discernible (78 and 90 dpf). GTH I was present in the proximal pars distalis at all dates (48-126 dpf), whereas GTH II was not detectable. GnRH was found at all dates (48-126 dpf) and was distributed in several areas of the brain including the nucleus preopticus periventricularis, nucleus lateralis tuberis, and the pituitary in the region where GTH I was found. No differences were seen between males and females in the timing of appearance, localization, or intensity of staining of these peptide hormones. Given that the brain-pituitary-gonadal axis seems to be intact during the process of sexual differentiation and the fluctuations of steroid levels during this process, sex steroids may play the driving role for sexual differentiation of rainbow trout.
journal_name
Gen Comp Endocrinoljournal_title
General and comparative endocrinologyauthors
Feist G,Schreck CBdoi
10.1006/gcen.1996.0083subject
Has Abstractpub_date
1996-06-01 00:00:00pages
394-409issue
3eissn
0016-6480issn
1095-6840pii
S0016-6480(96)90083-0journal_volume
102pub_type
杂志文章abstract：:Arsenic contaminates water surface and groundwater worldwide. Several studies have suggested that arsenic acts as an endocrine disruptor in mammalian and non-mammalian species, although its chronic effect during development remains largely unknown. To address this question, life cycle exposures to 0, 0.3 and 0.8ppm of...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1016/j.ygcen.2015.09.015
更新日期：2016-08-01 00:00:00
abstract：:Experimental data demonstrated the negative impact of maternal protein malnutrition (MPM) on rat prostate development, but the mechanism behind the impairment of prostate growth has not been well understood. Male Sprague Dawley rats, borned to dams fed a normal protein diet (CTR group, 17% protein diet), were compared...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1016/j.ygcen.2016.12.016
更新日期：2017-05-15 00:00:00
abstract：:Classical biotin deficiency in young chickens is characterized by a reduction in the activity of liver biotin-dependent enzymes which thus impairs gluconeogenesis during periods of food withdrawal. Because the normal bird maintains an elevated fasting blood glucose level, the ability of the classically biotin-deficien...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1016/0016-6480(87)90232-2
更新日期：1987-01-01 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：:Changes in testis size, histological status, and plasma levels of testosterone were monitored for males of three species of Western Australian desert frogs, Cyclorana maini, Cyclorana platycephala, and Neobatrachus sutor during aestivation. The frogs were induced to burrow and form cocoons soon after their capture and...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1016/j.ygcen.2003.12.005
更新日期：2004-03-01 00:00:00
abstract：:Rapid progestin effects on sperm physiology have been described in a variety of vertebrate species. Here, we briefly review the signaling pathways mediating rapid progestin induction of sperm hypermotility and increased fertility in two teleost species, Atlantic croaker and southern flounder. Acute in vitro treatment ...
journal_title：General and comparative endocrinology
pub_type： 杂志文章,评审
doi：10.1016/j.ygcen.2018.12.002
更新日期：2019-08-01 00:00:00
abstract：:In teleost fish, the predominant brain form of cytochrome P450 aromatase (P450aromB) is a neural marker of estrogen effect, and an entry point for studying the role of hormonal and environmental estrogens on neurodevelopment and neuroplasticity. As part of a project using zebrafish to investigate these issues, we deve...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1016/j.ygcen.2005.12.010
更新日期：2006-06-01 00:00:00
abstract：:We investigated the seasonal and daily variation in plasma glucose levels in response to stress in captive wild starlings. Starlings were captured from the wild during the winter, held on short days (11L:13D, mimicking winter), and then shifted to long days (19L:5D, mimicking summer). Birds were maintained on long day...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1006/gcen.2000.7492
更新日期：2000-07-01 00:00:00
abstract：:In many fishes, dopamine (DA) strongly inhibits luteinizing hormone (LH) release by direct action at the pituitary level. In this study, the effect of DA on LH synthesis was examined by detecting its β-subunit mRNA level in immature grass carp pituitary cells. Results showed that DA inhibited LHβ mRNA expression and i...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1016/j.ygcen.2011.04.024
更新日期：2011-08-01 00:00:00
abstract：:Seasonal patterns of fecal 17beta-OH-androgen, estrogen, and progesterone equivalents of male and female greylag geese (Anser anser) were analyzed in a flock of free-living geese. These were compared among social categories determined by pairbond status and breeding success. The annual cycle was divided into 13 phases...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1006/gcen.1998.7236
更新日期：1999-04-01 00:00:00
abstract：:Fetal development is a critical period of physical development, and factors in the intrauterine environment can cause lasting effects on the growth and development of offspring. There is little research evaluating organizational effects of early androgen exposure of endogenous maternal origins on the prenatal and post...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1016/j.ygcen.2009.10.008
更新日期：2010-04-01 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
pub_type： 杂志文章
doi：10.1006/gcen.1993.1009
更新日期：1993-01-01 00:00:00
abstract：:The effect of aldosterone and corticosterone on T3 binding to the nuclear fraction of the tail fin of bullfrog tadpoles was investigated in vitro. Both corticoids (10(-7) - 10(-5) M) added to the incubation medium increased T3 binding in a dose-dependent manner. The aldosterone-induced increase in T3-binding was block...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1016/0016-6480(83)90122-3
更新日期：1983-11-01 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
pub_type： 杂志文章
doi：10.1006/gcen.1993.1057
更新日期：1993-04-01 00:00:00
abstract：:Traditional views suggest that growth hormone and the growth hormone receptor (GH/GHR complex) exert their functions only on the plasma membrane. This paradigm, however, has been challenged by recent new findings that the GH/GHR complex could translocate into cell nuclei where they could still exhibit important physio...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1016/j.ygcen.2018.05.002
更新日期：2018-09-15 00:00:00
abstract：:The binding of 125I-labeled ovine prolactin (oPRL) to membrane preparations of tissue from freshwater-adapted tilapia (Sarotherodon mossambicus) was examined. Liver, ovary, and testis showed a relatively high specific binding (5-10%). A lower specific binding occurred consistently in intestine and gill tissue, and inc...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1016/0016-6480(84)90056-x
更新日期：1984-10-01 00:00:00
abstract：:In the current study we describe the identification of novel leptin B homologous gene/s in the four salmonid species Atlantic salmon (Salmo salar), rainbow trout (Oncorhynchus mykiss), brown trout (Salmo trutta) and Arctic charr (Salvelinus alpinus). Homology modeling of Salmo salar (Ss) LepB1/B2 suggests that the pro...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1016/j.ygcen.2013.03.022
更新日期：2013-06-15 00:00:00
abstract：:Gonadal sex in the red-eared slider turtle is determined by the incubation temperature that the embryo experiences during the mid-trimester of development. High temperatures result in female-biased sex ratios, and low temperatures produce male-biased sex ratios. The physiological equivalent of temperature appears to b...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1006/gcen.2000.7505
更新日期：2000-08-01 00:00:00
abstract：:The sex steroids testosterone (T) and estradiol-17beta (E2) play important roles in vertebrate reproduction and development. However, little is known about the relationship between plasma steroid levels (which can influence reproductive function) and yolk steroid levels (which can influence embryonic development) in o...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1016/s0016-6480(03)00240-5
更新日期：2003-11-01 00:00:00
abstract：:The golden rabbitfish Siganus guttatus is a reef fish with a restricted lunar-synchronized spawning rhythmicity and releases gametes simultaneously around the first quarter moon period during the spawning season. In order to understand the molecular aspects of the "circa" rhythms in this species, the full-length melat...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1016/j.ygcen.2006.08.011
更新日期：2007-01-15 00:00:00
abstract：:Serum levels of 17 beta-hydroxy-4-androstene-3,11-dione (11-KT) and testosterone in the protogynous black sea bass, Centropristis striatus fluctuate annually, correlated with the breeding season. Although serum 11-KT levels in both males and females exhibit seasonality, serum estradiol-17 beta concentrations cycle ann...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1016/0016-6480(91)90297-j
更新日期：1991-04-01 00:00:00
abstract：:The existence of direct progestin actions on teleost sperm to stimulate hypermotility is not widely acknowledged because it has only been demonstrated in members of the family Sciaenidae. In the present study, progestin stimulation of sperm hypermotility was investigated in a non-sciaenid, southern flounder, and the p...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1016/j.ygcen.2010.12.005
更新日期：2011-02-01 00:00:00
abstract：:Cardiovascular responses to synthetic eel [Asn1, Val5, Gly9]-ANG-I, ANG-III (2-8), and ANG-I (1-7) were measured in conscious and resting freshwater North American eels. Indwelling Doppler flow probes were placed on the ventral and dorsal aortas, a pressure catheter in the lienomesenteric artery, and a peptide deliver...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1006/gcen.1995.1025
更新日期：1995-02-01 00:00:00
abstract：:Ovarian follicles isolated from rainbow trout during early exogenous vitellogenesis were used to study the in vitro effects of thyroid hormones on salmon gonadotropin (GtH)-induced estradiol-17 beta (E2) secretion. Triiodothyronine (T3) alone did not alter E2 secretion but T3 in the presence of GtH (0.5 micrograms/ml)...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1016/0016-6480(88)90055-x
更新日期：1988-01-01 00:00:00
abstract：:This study investigated the pathways to many monoamines and their metabolites in the central nervous system of the frog Rana nigromaculata and the toad Bufo bufo japonicus during embryonic development and metamorphosis. Metabolites were analyzed by three-dimensional HPLC. The two species provided evidence of similar p...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1006/gcen.1997.6885
更新日期：1997-06-01 00:00:00
abstract：:Vertebrate eggs are surrounded by an extracellular glycoprotein coat termed zona pellucida (ZP). Integrity of ZP is critical for a correct embryo development. Two zona pellucida protein genes (zpb and zpc) from European eel were characterized, specific qPCR assays developed and their expression in immature males and f...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1016/j.ygcen.2012.06.003
更新日期：2012-09-01 00:00:00
abstract：:The endocrine pancreas of the lizard Podarcis hispanica is described using light and electron microscopy. The endocrine pancreas of this reptile is located throughout the spleen side of the organ and consists of islet-like structures, small groups of two to five cells, and single scattered endocrine cells. The endocri...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1016/0016-6480(88)90250-x
更新日期：1988-08-01 00:00:00
abstract：:Endogenous cyclic-AMP concentrations in Malpighian tubules of locusts increase as a result of diuretic hormone stimulation, and the level of increase is shown to be dependent on basal intracellular levels of cyclic-AMP. Furthermore, the increase in endogenous cyclic-AMP is in such excess as to cause excretion of high ...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1016/0016-6480(84)90195-3
更新日期：1984-04-01 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：:In vertebrates, the peptide cholecystokinin (CCK) is one of the most important neuroregulatory digestive hormones. CCK acts via CCK receptors that are classified into two subtypes, CCK-1 receptor (CCK-1R; formally CCK-A) and CCK-2 receptor (formally CCK-B). In particular, the CCK-1R is involved in digestion and is reg...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1016/j.ygcen.2013.02.003
更新日期：2013-06-01 00:00:00
