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), THEP layer, or GCEOs were cultured for 6 hr in amphibian Ringer's in the presence or absence of various steroid precursors (100 ng/ml) or of frog pituitary homogenate (FPH, 0.05 gland/ml). The amounts of progesterone (P4), 17 alpha-hydroxyprogesterone (17 alpha-OHP4), androstenedione (AD), testosterone (T), and estradiol (E2) secreted into the medium by the different types of follicular components during culture were measured by radioimmunoassay. Addition of pregnenolone resulted in a marked increase in P4 concentrations produced by GCEOs (1858 pg/follicle) and IFs (1549 pg/follicle), but a much smaller increase in P4 occurred in the THEP layer (427 pg/follicle). Likewise, addition of P4 stimulated greater production of 17 alpha-OHP4 by GCEOs (659 pg/follicle) and by IFs (877 pg/follicle) than by the THEP layer (330 pg/follicle). Exogenous 17 alpha-OHP4 markedly increased AD levels secreted by GCEOs (1139 pg/follicle) and by IFs (841 pg/follicle), but not by the THEP layer (< 15 pg/follicle). In contrast, AD addition resulted in the secretion of markedly elevated levels of T by the THEP layer (2326 pg/follicle) and IFs (3652 pg/follicle) as compared to the GCEOs (408 pg/follicle). Addition of T markedly increased E2 concentrations produced by GCEOs (378 pg/follicle) and by IFs (673 pg/follicle), but not by the THEP layer (< 12 pg/follicle).(ABSTRACT TRUNCATED AT 250 WORDS)
journal_name
Gen Comp Endocrinoljournal_title
General and comparative endocrinologyauthors
Kwon HB,Ahn RSdoi
10.1006/gcen.1994.1077subject
Has Abstractpub_date
1994-05-01 00:00:00pages
207-14issue
2eissn
0016-6480issn
1095-6840pii
S0016-6480(84)71077-Xjournal_volume
94pub_type
杂志文章abstract：:There are more CRH-like immunoreactive neurons in the preoptic nucleus and nucleus lateralis tuberis in the brain of feral brown trout, Salmo trutta, living in cadmium- and zinc-contaminated regions of the Eagle River than in fish from an uncontaminated control site. Histological analyses revealed that interrenal cell...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1006/gcen.1997.7000
更新日期：1997-12-01 00:00:00
abstract：:Somatostatin receptors (sst) mediate the numerous physiological actions (e.g., aspects of growth, development, and metabolism) of the somatostatin family of peptides. In this study, we used rainbow trout (Oncorhynchus mykiss) to establish the pattern of sst subtype 1A, 1B, and 2 mRNA expression in selected tissues (op...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1016/j.ygcen.2004.09.008
更新日期：2004-12-01 00:00:00
abstract：:The endocannabinoid system is a major regulator of food intake in many animal species. Studies conducted so far have mostly focused on mammals, and, therefore, in this study, the role of the endocannabinoid system in food intake in the sea bream Sparus aurata was investigated. The effect of different doses of the endo...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1016/j.ygcen.2009.09.017
更新日期：2010-04-01 00:00:00
abstract：:Birds rely solely on utilization of the yolk sac as a means of nutritional support throughout embryogenesis and early post-hatch, before first feeding occurs. Newly hatched broiler (meat-type) chickens are frequently not given immediate access to feed, and this can result in numerous alterations to developmental proce...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1016/j.ygcen.2020.113445
更新日期：2020-06-01 00:00:00
abstract：:Three gonadotropin-releasing hormones (GnRHs) and three cognate receptors have been identified in vertebrates, with distinct distributions and functions. According to their sequences, the receptors can be grouped into distinct classes: types I, II, and III. One branch contains all type-I GnRH receptors (GnRH-R-I) from...
journal_title：General and comparative endocrinology
pub_type： 杂志文章,评审
doi：10.1016/j.ygcen.2005.01.019
更新日期：2005-05-15 00:00:00
abstract：:This study examines the regulation of thyroid activity in adult rough-skinned newts, Taricha granulosa. Aquatic, breeding-condition newts were hypophysectomized and were injected for 23 days with the mammalian adenohypophysial hormones: ACTH, PRL, and GH. During a fourth week of treatment, these newts also received TS...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1016/0016-6480(85)90385-5
更新日期：1985-08-01 00:00:00
abstract：:The crab-eating frog Fejervarya cancrivora inhabits mangrove swamps and marshes in Southeast Asia. In the present study, circulating angiotensin II (Ang II), aldosterone (Aldo), arginine vasotocin (AVT), and corticosterone (Cort) concentrations as well as various blood parameters were studied under osmotically stressf...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1016/j.ygcen.2013.10.013
更新日期：2014-01-01 00:00:00
abstract：:Studies of the ontogeny of IGF-I mRNA during embryonic and larval development of the gilthead sea bream Sparus aurata showed its expression during these early developmental stages. The present study applies in situ hybridization to localize IGF-I and IGF receptor mRNAs in 16-day larvae of S. aurata. Paraffin sections ...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1006/gcen.1997.6935
更新日期：1997-09-01 00:00:00
abstract：:Juvenile hormone (JH) regulation of the synthesis of LHPI, the major secretory protein of the long hyaline tubule in the male accessory reproductive gland (MARG) of Melanoplus sanguinipes, was examined by in vitro radiolabeling and immunoprecipitation. In MARG taken from normal insects JH III immediately stimulates pr...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1006/gcen.1995.1046
更新日期：1995-04-01 00:00:00
abstract：:This set of experiments investigated the role of protein kinase-C (PKC) as a second messenger in vasoactive intestinal peptide (VIP)-stimulated prolactin (PRL) secretion and PRL mRNA abundance. Dispersed anterior pituitary cells (5 x 10(5) or 10(6) cells/tube) were isolated from laying turkeys and incubated in 1.0 ml ...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1006/gcen.1995.1112
更新日期：1995-09-01 00:00:00
abstract：:The factors influencing prolactin (PRL) variation in birds and in wildlife in general have rarely been investigated with respect to the physiological impacts of exposure to environmental contaminants. We investigated the associations between circulating baseline PRL levels and concentrations of eight persistent organo...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1016/j.ygcen.2008.02.013
更新日期：2008-05-01 00:00:00
abstract：:Gonadotropin-releasing hormone (GnRH) and its receptor are essential for reproduction in vertebrates. Although there are three major types of GnRH peptides and two major types of receptors in vertebrates, the pattern of distribution is unusual. Evidence is presented from genome mining that type I GnRHRs are not restri...
journal_title：General and comparative endocrinology
pub_type： 杂志文章,评审
doi：10.1016/j.ygcen.2014.07.025
更新日期：2014-12-01 00:00:00
abstract：:Undifferentiated spermatogonia (Aund) or spermatogonial stem cells (SSCs) are committed to the establishment and maintenance of spermatogenesis and fertility throughout a male's life and are located in a highly specialized microenvironment called niche that regulates their fate. Although several studies have been deve...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1016/j.ygcen.2018.06.019
更新日期：2019-03-01 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
pub_type： 杂志文章
doi：10.1016/0016-6480(89)90034-8
更新日期：1989-10-01 00:00:00
abstract：:Glucocorticoid hormones allow individuals to rapidly adjust their physiology and behavior to meet the challenges of a variable environment. An individual's baseline concentration of glucocorticoids can reflect shifts in life history stage and resource demands while mediating a suite of physiological and behavioral cha...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1016/j.ygcen.2017.07.006
更新日期：2018-01-15 00:00:00
abstract：:In mammals ghrelin has a diverse range of effects including stimulation of gut motility but although present in teleost fish its effects on motility have not been investigated. The present study used bioinformatics to search for fish paralogues of the ghrelin receptor and the closely related motilin receptor, and inve...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1016/j.ygcen.2007.05.016
更新日期：2008-01-01 00:00:00
abstract：:Aromatase is the key enzyme for estrogen biosynthesis and is encoded by Cyp19 gene. Placental cotyledons are the main site of Cyp19 gene expression during pregnancy. The present study was aimed to investigate if DNA methylation and thus epigenetic mechanisms play a potential role in stage-specific regulation of Cyp19 ...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1016/j.ygcen.2010.07.012
更新日期：2010-11-01 00:00:00
abstract：:Because of the high degree of primary sequence conservation in neuropeptides and low molecular weight polypeptide hormones, these polypeptides are not useful for constructing phylogenetic trees based on maximum parsimony analysis. This review focuses on the organization of neuropeptide and polypeptide hormone precurso...
journal_title：General and comparative endocrinology
pub_type： 杂志文章,评审
doi：10.1006/gcen.1996.0088
更新日期：1996-07-01 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
pub_type： 杂志文章
doi：10.1006/gcen.1993.1019
更新日期：1993-01-01 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
pub_type： 杂志文章
doi：10.1006/gcen.1993.1146
更新日期：1993-10-01 00:00:00
abstract：:Gonadotropin-inhibitory hormone (GnIH) is a hypothalamic neuropeptide that was isolated from the brains of Japanese quail in 2000, which inhibited luteinizing hormone release from the anterior pituitary gland. Here, we summarize the following fifteen years of researches that investigated on the mechanism of GnIH actio...
journal_title：General and comparative endocrinology
pub_type： 杂志文章,评审
doi：10.1016/j.ygcen.2015.09.009
更新日期：2016-02-01 00:00:00
abstract：:GPCRs are the largest family of receptors accounting for about 30% of the current drug targets. However, it is difficult to fully elucidate the mechanisms regulating intracellular GPCR signal regulation. It is thus important to consider and investigate GPCRs with respect to endogenous situations. Our group has been in...
journal_title：General and comparative endocrinology
pub_type： 杂志文章,评审
doi：10.1016/j.ygcen.2020.113474
更新日期：2020-07-01 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：:Effects of epidermal growth factor (EGF) and possible mechanisms of EGF-mediated signal transduction were investigated in isolated cells of the digestive gland of the mussel (Mytilus galloprovincialis Lam. ). EGF induced a cytosolic Ca2+ transient and subsequently stimulated DNA synthesis; both effects were dose-depen...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1006/gcen.1997.6918
更新日期：1997-08-01 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
pub_type： 杂志文章
doi：10.1016/0016-6480(90)90230-j
更新日期：1990-03-01 00:00:00
abstract：:Prolactin (PRL) plays central roles in a wide range of body functions in mammals, and the actions are mediated by the specific cell surface receptor, the prolactin receptor (PRLR). To better understand the role of PRL in the yak (Bos grunniens), in the present study, we first cloned yak PRLR cDNA, and compared its mRN...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1016/j.ygcen.2011.12.004
更新日期：2012-02-01 00:00:00
abstract：:Y-Organs and control tissues from intact (intermolt) and 48-hr de-eyestalked Cancer antennarius donors were cultured for 12 and 24 hr in crustacean saline supplemented 10% with crab serum and containing [14C]cholesterol. Under these conditions, Y-organs took up significantly more [14C]cholesterol than ovary or muscle,...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1016/0016-6480(85)90215-1
更新日期：1985-03-01 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：:The effect of bursa of Fabricius on the endocrine function of the chick testis was studied using an isolated testis cell preparation. Testosterone secretion, both basal and under hCG stimulation, was measured in the incubation medium. The bursal extract inhibited the response of the testis cells to hCG detected as a r...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1016/0016-6480(85)90208-4
更新日期：1985-01-01 00:00:00
abstract：:The concentrations of norepinephrine in hypothalamus and norepinephrine and epinephrine in head kidney were significantly decreased in treated tilapia (Oreochromis aureus) during the time course of cold exposure (12 degrees) as compared to the control (25 degrees). The elevation of norepinephrine and epinephrine in pl...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1006/gcen.2001.7772
更新日期：2002-03-01 00:00:00
