Abstract：
:The circulating serum concentrations of various steroid hormones in mature sockeye salmon were measured at four different developmental stages in their upstream migration to spawn at Adams River in British Columbia, Canada. In females, a high level of estradiol-17 beta was found in fish at the first location, and it persisted until immediately before reaching the spawning grounds, 485 km upstream, where it decreased to a minimal level. Free testosterone was extremely high throughout the migration but decreased significantly after spawning while its glucuronide changed reciprocally. Free and conjugated 17 alpha, 20 beta-dihydroxy-4-pregnen-3-one (17 alpha, 20 beta-P) peaked at the last location before spawning with the glucuronide only 20% of the free steroid in concentration. After spawning, the concentration of free steroid declined but the glucuronide remained constant. 17 alpha-hydroxyprogesterone increased significantly in serum before and after the fish had spawned. During the migration 11-deoxycortisol was present in the serum at all stages but maximal levels were found in postspawned fish. Throughout the migration, the males had high serum levels of 11-ketotestosterone. Lesser amounts of free testosterone were also consistently present but the ratio of free: conjugated decreased from 1.7 at the beginning of the migration to 0.15 on the arrival at the Adams River and 0.10 in postspawned fish. Only low levels of 11 beta-hydroxytestosterone were found except in the postspawned males where the value was equal to one-half that of free testosterone. As in the females, there was a substantial increase in the levels of 17 alpha, 20 beta-P and its glucuronide in the males captured at the spawning grounds. In both sexes gonadotropin levels were low during the migration and high in the postspawned fish.
journal_name
Gen Comp Endocrinoljournal_title
General and comparative endocrinologyauthors
Truscott B,Idler DR,So YP,Walsh JMdoi
10.1016/0016-6480(86)90098-5subject
Has Abstractpub_date
1986-04-01 00:00:00pages
99-110issue
1eissn
0016-6480issn
1095-6840pii
0016-6480(86)90098-5journal_volume
62pub_type
杂志文章abstract：:Pinealectomized and intact chicks raised under cyclic (14L:10D) and noncyclic (OL;24L) conditions of environmental lighting were sampled 60 hr and 6 weeks after pinealectomy to evaluate the effects of pineal ablation on plasma and ocular melatonin concentrations. Little or no immunoreactive melatonin was present in pl...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1016/0016-6480(85)90114-5
更新日期：1985-06-01 00:00:00
abstract：:In altricial songbirds, food restriction in early development has adverse effects on various physiological systems. When conditions improve birds can accelerate growth, but this compensatory strategy is associated with long-term adverse consequences. One system affected by altered growth rates is the hypothalamic-pitu...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1016/j.ygcen.2015.08.001
更新日期：2015-10-01 00:00:00
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journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1006/gcen.1996.0145
更新日期：1996-10-01 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：:Gonadotrophin-releasing hormone (GnRH) is primarily related to reproductive processes in vertebrates. However other physiological roles, including functions in food intake regulation and energy status, have been demonstrated for GnRH in animals. The ten amino acid active peptide is relatively conserved throughout chor...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1016/j.ygcen.2012.12.010
更新日期：2013-04-01 00:00:00
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journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1016/j.ygcen.2014.03.018
更新日期：2014-10-01 00:00:00
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journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1016/0016-6480(90)90115-3
更新日期：1990-08-01 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
pub_type： 杂志文章
doi：10.1006/gcen.1994.1185
更新日期：1994-11-01 00:00:00
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journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1016/0016-6480(86)90059-6
更新日期：1986-06-01 00:00:00
abstract：:Pituitary melanotrope cells of the amphibian Xenopus laevis are neuroendocrine cells regulating the animal's skin color adaptation through secretion of α-melanophore-stimulating hormone (α-MSH). To fulfill this function optimally, the melanotrope cell undergoes plastic changes in structure and secretory activity in re...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1016/j.ygcen.2010.08.010
更新日期：2010-11-01 00:00:00
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journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1016/0016-6480(88)90291-2
更新日期：1988-07-01 00:00:00
abstract：:Rhythmic synthesis of moulting hormones (ecdysteroids) by prothoracic glands (PGs) of the insect Rhodnius prolixus during the last larval instar was studied in vitro following explantations every 4-5 hr for up to 96 hr. Ecdysteroid synthesis was measured by radioimmunoassay as the quantity of ecdysteroid produced duri...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1016/0016-6480(91)90102-c
更新日期：1991-07-01 00:00:00
abstract：:Previous data have shown that regional differences in the presence of anterior pituitary luteinizing hormone (LH) generally correlate with the comparable disparities in distribution of gonadotropes throughout the gland. In female rats, the differences are apparent over the estrous cycle, but are more prominent during ...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1016/j.ygcen.2008.02.015
更新日期：2008-05-01 00:00:00
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journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1016/0016-6480(90)90187-q
更新日期：1990-12-01 00:00:00
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journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1016/j.ygcen.2009.12.009
更新日期：2010-04-01 00:00:00
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journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1006/gcen.1994.1143
更新日期：1994-09-01 00:00:00
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journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1016/j.ygcen.2009.01.022
更新日期：2009-05-01 00:00:00
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journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1016/j.ygcen.2011.09.017
更新日期：2011-12-01 00:00:00
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journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1016/j.ygcen.2008.04.014
更新日期：2008-06-01 00:00:00
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journal_title：General and comparative endocrinology
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更新日期：2018-01-15 00:00:00
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journal_title：General and comparative endocrinology
pub_type： 杂志文章
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更新日期：2011-03-01 00:00:00
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 ...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
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更新日期：2011-12-01 00:00:00
abstract：:Two forms of immunoreactive gonadotropin-releasing hormone (GnRH) were extracted from brain-pituitary tissues of Thai catfish, Clarias macrocephalus and C. batrachus. The peptides were detected using high performance liquid chromatography (HPLC) and radioimmunoassay (RIA). In both the HPLC systems, catfish GnRH-I elut...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1016/0016-6480(92)90031-e
更新日期：1992-08-01 00:00:00
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journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1006/gcen.1999.7363
更新日期：1999-11-01 00:00:00
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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
abstract：:Effects of adrenal corticosteroids on reproductive and endocrine functions of the gonads are well known, but reciprocal effects of gonadal hormones on the hypothalamo-pituitary-adrenal (HPA) axis and on adrenocortical steroidogenesis in particular have received much less attention. We investigated effects of gonadecto...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1016/j.ygcen.2008.07.018
更新日期：2008-09-01 00:00:00
abstract：:Red deer stags have a seasonal pattern of growth, alternating between periods of summer weight gain and winter weight loss that are influenced by photoperiod and by exogenous melatonin. A seasonal pattern of plasma insulin-like growth factor 1, also influenced by photoperiod, underlies the seasonal growth pattern. The...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1016/0016-6480(92)90156-e
更新日期：1992-07-01 00:00:00
abstract：:Melatonin and arylalkylamine N-acetyltransferase (AANAT), the rate-limiting enzyme in melatonin synthesis, have taken on special importance in vertebrate circadian biology. Recent identification of genes encoding two AANAT (AANAT(1) and AANAT(2)) and two subtypes of melatonin receptor (Mel-R; Mel(1a) and Mel(1b)) in s...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1016/j.ygcen.2004.01.004
更新日期：2004-05-01 00:00:00
abstract：:Many marine invertebrate larvae undergo a dramatic morphological and physiological transition from a planktonic larva to a benthic juvenile. The mechanisms of this metamorphosis in bivalves are mainly unknown. The recent identification in bivalves of a thyroid hormone receptor (TR) gene raises the possibility that as ...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1016/j.ygcen.2019.113347
更新日期：2020-02-01 00:00:00
