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 microliters was developed. The steroids were extracted with Sep-Pak C18 cartridges after heat treatment. While estradiol-17 beta was assayed directly after extraction, the other steroids were separated on a mu Bondapak C18 stainless-steel column with acetonitrile:water (53:47, v/v) in 17 min under isocratic conditions, and then quantitated by specific radioimmunoassays. The technique was validated and was shown to be highly accurate, precise, sensitive, and specific for measuring those particular ovarian steroids in goldfish serum. The steroid levels measured in this way were not significantly different from those measured after separation on a Nova-Pak C18 column with methanol:water (56:44, v/v), where all the individual steroids could be completely resolved during a 40-min run. With this technique, the steroid levels in the serum of the goldfish during the secondary yolk stage, the tertiary yolk stage, and at 0 hr after ovulation were determined. While estradiol-17 beta was found to be significantly higher in the tertiary yolk stage, testosterone was significantly higher in the secondary yolk stage than in the other two stages. There was no significant difference in the levels of cortisol, 17 alpha-hydroxyprogesterone,17 alpha,20 beta-dihydroxy-4-pregnen-3-one, and progesterone among the three stages. We conclude that the technique is particularly useful for assaying multiple steroids in very small volumes of biological fluids.
journal_name
Gen Comp Endocrinoljournal_title
General and comparative endocrinologyauthors
Venkatesh B,Tan CH,Lam TJdoi
10.1016/0016-6480(89)90135-4subject
Has Abstractpub_date
1989-12-01 00:00:00pages
398-407issue
3eissn
0016-6480issn
1095-6840pii
0016-6480(89)90135-4journal_volume
76pub_type
杂志文章abstract::The Harderian gland of the lizard Podarcis sicula sicula (Raf) contains connective tissue type mast cells whose numbers vary during the year showing two peaks, one in spring the other in winter. No sex differences are found throughout the year. Thermal and photoperiodic manipulations indicate that only temperature inf...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1006/gcen.1997.6925
更新日期:1997-09-01 00:00:00
abstract::Aromatase is a key regulator of circulating testosterone (T) and 17-β-oestradiol (E2), two steroids which are critical to the development, maintenance and function of reproductive tissues. The role of aromatase in sexual differentiation in oviparous (egg-laying) reptiles is well understood, yet has never been explored...
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journal_title:General and comparative endocrinology
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doi:10.1016/0016-6480(87)90026-8
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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
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journal_title:General and comparative endocrinology
pub_type: 杂志文章
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更新日期:2003-11-01 00:00:00
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journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2016.02.019
更新日期:2016-04-01 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:2016-10-01 00:00:00
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journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/0016-6480(85)90401-0
更新日期:1985-09-01 00:00:00
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journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1006/gcen.1993.1179
更新日期:1993-12-01 00:00:00
abstract::The role of ovarian hormones in the expression of parental behavior and in the regulation of LH secretion was investigated in incubating commercial meat-type hens. After ovariectomy, incubating hens continued to incubate eggs normally and brooded day-old chicks given to replace eggs, in a manner similar to sham-ovarie...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1006/gcen.1996.0013
更新日期:1996-01-01 00:00:00
abstract::Perchlorate, an environmental contaminant, disrupts normal functioning of the thyroid. We previously showed that perchlorate disrupts behavior and gonad development, and induces external morphological changes in a vertebrate model organism, the threespine stickleback. Whether perchlorate alters these phenotypes via a ...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2014.10.015
更新日期:2015-01-01 00:00:00
abstract::The brains of goldfish and other teleosts contain high-affinity binding sites for [3H][3-methyl-His2]thyrotropin-releasing hormone [( 3H]MeTRH) which closely resemble TRH receptors in mammalian brain and pituitary gland in apparent dissociation constant (KD = 3-4 nM), in pharmacology for eight TRH analogs, and in exhi...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/0016-6480(84)90233-8
更新日期:1984-01-01 00:00:00
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journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2008.02.011
更新日期:2008-05-01 00:00:00
abstract::Variation in food intake affects somatic growth by altering the expression of hormones in the somatotropic endocrine axis including insulin-like growth factor-1 (IGF-1). Here, we examined IGF-1 pathway responses to long- and short-term variation in food availability in copper rockfish (Sebastes caurinus), a nearshore ...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2019.04.025
更新日期:2019-09-01 00:00:00
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journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/0016-6480(92)90156-e
更新日期:1992-07-01 00:00:00
abstract::Thyroid hormones (TH) are key regulators of metabolism and development, yet our understanding of the variability in serum TH concentrations in free-ranging marine mammals is limited. Thus, we examined the interrelationships between TH and age, sex, reproductive status, geographic location, and ocean temperatures in wi...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2011.08.021
更新日期:2011-11-01 00:00:00
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journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1006/gcen.1996.0162
更新日期:1996-11-01 00:00:00
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journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1006/gcen.1996.0135
更新日期:1996-10-01 00:00:00
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journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1006/gcen.1995.1015
更新日期:1995-01-01 00:00:00
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journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2015.09.031
更新日期:2015-11-01 00:00:00
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journal_title:General and comparative endocrinology
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doi:10.1016/j.ygcen.2017.01.032
更新日期:2017-06-01 00:00:00
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journal_title:General and comparative endocrinology
pub_type: 杂志文章,评审
doi:10.1016/j.ygcen.2011.08.017
更新日期:2012-01-01 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
pub_type: 杂志文章
doi:10.1006/gcen.1993.1010
更新日期:1993-01-01 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
abstract::The box turtle (Terrapene carolina triunguis) does not appear to have evolved a mechanism for secondary bone formation similar to Aves inasmuch as several parameters of bone calcium metabolism were unaffected by estrogen treatment. This suggests that reproduction does not constitute a substantial stress to the calcium...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/0016-6480(84)90212-0
更新日期:1984-04-01 00:00:00
abstract::Seasonally-breeding amphibians have served as excellent animal models to investigate the biosynthesis and biological actions of neurosteroids. Previous studies have demonstrated that the brain of amphibians possesses key steroidogenic enzymes and produces pregnenolone, a precursor of steroid hormones, and other variou...
journal_title:General and comparative endocrinology
pub_type: 杂志文章,评审
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更新日期:2012-05-01 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::Optimization of food consumption and ultimately growth are major concerns for aquaculture. In fish, food intake is regulated by several hormones produced by both brain and peripheral tissues. Changes in feeding behavior and appetite usually occur through the modulation of the gene expression and/or action of these app...
journal_title:General and comparative endocrinology
pub_type: 杂志文章,评审
doi:10.1016/j.ygcen.2009.09.001
更新日期:2010-07-01 00:00:00
abstract::Natriuretic peptide type C (NPPC) and its receptor, natriuretic peptide receptor 2 (NPR2), have essential roles in maintaining meiotic arrest of oocytes in several mammalian species. However, it is not known if a similar mechanism exists in non-mammalian vertebrates. Using zebrafish as a model, we show that Nppc is ex...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2018.03.024
更新日期:2018-09-01 00:00:00
abstract::To better understand the role(s) of progesterone in fish spermatogenesis, we cloned the nuclear progesterone receptor (Pgr) of Atlantic cod. The open-reading frame of the cod pgr consists of 2076 bp, coding for a 691-amino acids-long protein that shows the highest similarity with other piscine Pgr proteins. Functional...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2012.07.022
更新日期:2012-10-01 00:00:00