Abstract:
:Many vertebrates have more than one molecular form of gonadotropin-releasing hormone (GnRH) present in brain. In all cases documented to date, GnRH neurons located in the forebrain are critical players in the brain-pituitary-gonadal feedback axis although the details of how steroids regulate GnRH remain elusive. The function of the second form, usually produced in cells in the midbrain, is not known. It has been hypothesized that this GnRH acts as a neurotransmitter. In the musk shrew (Suncus murinus), as in other mammals, the forebrain cells produce mammalian GnRH (mGnRH) and chicken-II GnRH (cGnRH-II) is present in midbrain neurons. Immunocytochemical analyses were performed to examine sex differences and determine whether the presence or absence of the gonads had any affect on cell number and/or fiber area in the major terminal fields of both forms of GnRH. We detected a significant sex difference in the numbers of immunoreactive (ir) neurons containing mGnRH and cGnRH-II. In both GnRH systems, males have significantly more GnRH-ir cells than females. Furthermore, ovariectomy significantly increased the number of mGnRH-ir and cGnRH-II-ir cell bodies in female brains. In females, changes in the size of the immunoreactive fiber area of the medial habenula were identical to those noted for cGnRH-II cells. In males, the major terminal field for the mGnRH fibers was significantly larger in gonad-intact than in castrated males. In sum, ovarian hormones regulate cGnRH-II production and release, as well as some aspects of mGnRH production in neurons. In males, mGnRH fiber area is sensitive to changes in testicular hormones. These data suggest that the phylogenetically conserved cGnRH-II form is regulated by ovarian hormones and, thus, may be involved in the brain-pituitary-gonadal feedback axis.
journal_name
Gen Comp Endocrinoljournal_title
General and comparative endocrinologyauthors
Rissman EF,Li Xdoi
10.1006/gcen.1998.7135subject
Has Abstractpub_date
1998-12-01 00:00:00pages
346-55issue
3eissn
0016-6480issn
1095-6840pii
S0016-6480(98)97135-0journal_volume
112pub_type
杂志文章abstract::Animals in captivity and in the wild face numerous challenges, including the risk of enduring acute or chronic stress. In captivity, facilities attempt to alleviate the risk of chronic stress by providing environmental enrichment, shown to minimize behavioral disorders and stress in several species. One potential form...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2014.11.007
更新日期:2015-01-15 00:00:00
abstract::Using DNA-cellulose affinity chromatography, an estrogen-binding component having the properties of a classical estrogen receptor was characterized from testicular cytosol of the freshwater turtle, Chrysemys picta. This putative cytoplasmic receptor exhibited high affinity (Kd = 7.0 X 10(-10) M), low capacity (1-4 fmo...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/0016-6480(83)90111-9
更新日期:1983-11-01 00:00:00
abstract::The aim of present study was to investigate the role of androgen in sperm storage in the female genital tract of Scotophilus heathi. Spermatozoa were observed in the distal part of oviduct and utero-tubal junction of all the female bats collected between January and early March. Increase in circulating testosterone le...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2009.06.012
更新日期:2010-01-01 00:00:00
abstract::Recently, zebrafish has quickly risen as a model species for functional analysis of the brain-pituitary-gonad axis. However, one of the hurdles for such work in this popular model organism is the small size of its pituitary gland, which makes it difficult to investigate the regulation of pituitary hormone expression a...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2008.11.020
更新日期:2009-01-15 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
pub_type: 杂志文章
doi:10.1016/0016-6480(90)90154-e
更新日期:1990-10-01 00:00:00
abstract::Anthropogenic emissions of carbon dioxide in the atmosphere have generated rapid variations in atmospheric composition which drives major climate changes. Climate change related effects include changes in physico-chemical proprieties of sea and freshwater, such as variations in water temperature, salinity, pH/pCO2 and...
journal_title:General and comparative endocrinology
pub_type: 杂志文章,评审
doi:10.1016/j.ygcen.2020.113439
更新日期:2020-05-15 00:00:00
abstract::Although asymmetric development of the ovary and the oviduct is a unique characteristic in birds, the mechanism of asymmetric development still remains unclear. Recently, degradation of extracellular matrix has been suggested as an important factor related to the regression of the Müllerian duct in mammals. The presen...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2004.08.003
更新日期:2004-11-01 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::Seasonal changes in testicular structure and function in three species of Korean frogs (Rana nigromaculata, R. rugosa, and R. dybowskii) having different breeding seasons and habitats were examined throughout the year. R. nigromaculata live in rice fields and breed in early May. Their gonadosomatic index (GSI) and tes...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1006/gcen.1998.7118
更新日期:1998-09-01 00:00:00
abstract::The purpose of this study was to examine the effect of the daily infusion of corticosterone on reproductive function in the laying hen and to determine the relationship between the cyclic pattern of plasma concentrations of corticosterone on the open-period for the preovulatory release of LH. An exogenous rhythm of pl...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/0016-6480(91)90145-v
更新日期:1991-09-01 00:00:00
abstract::Anuran amphibians do not drink orally but absorb water osmotically through the highly permeable ventral skin. In this cutaneous water absorption, roles of the putative cerebral osmoreceptors and functions of arginine vasotocin (AVT) were examined in the central nervous system of the Japanese treefrog, Hyla japonica. I...
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
abstract::Reproductive maturation and regulation is centrally orchestrated by gonadotropin-releasing hormone (GnRH). GnRH produced in the vertebrate hypothalamus acts on the pituitary to regulate gonadotropins. In nonplacental mammalian species, it has recently been shown that a second GnRH gene is expressed in mesencephalic ce...
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
abstract::Maternally derived yolk steroids have been found to elicit both short-term and long-term effects on offspring phenotype. Paradoxically, their effects can be strikingly specific given the often substantial concentrations present at oviposition, and they do not appear to uniformly affect all steroid-sensitive processes....
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2009.01.018
更新日期:2009-04-01 00:00:00
abstract::Growth hormone (GH) has many actions in vertebrates, including the regulation of two disparate metabolic processes: growth promotion (anabolic) and the mobilization of stored lipids (catabolic). Our previous studies showed that GH stimulated IGF-1 production in hepatocytes from fed rainbow trout, but in cells from fas...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2017.04.005
更新日期:2017-07-01 00:00:00
abstract::Ghrelin, and nesfatin-1 (encoded by nucleobindin2/nucb2) are two metabolic peptides with multiple biological effects in vertebrates. While sex steroids are known to regulate endogenous ghrelin and NUCB2 in mammals, such actions by steroids in fish remain unknown. This study aimed to determine whether estradiol (E2) an...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2016.01.006
更新日期:2016-03-01 00:00:00
abstract::On the basis of morphological characteristics of granulosa cells surrounding the oocyte, the small follicles (Class 1) in the ovary of the musk shrew were classified into four groups: Type B (flattened cells), Type B/C (mixture of flattened and cuboidal cells), Type C (single layer of cuboidal cells), and Type D (more...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/0016-6480(92)90001-z
更新日期:1992-02-01 00:00:00
abstract::The discovery of novel members of the CRF neuropeptide family, urocortin 1 (Ucn1), urocortin 2 and 3 has provided important insights into stress adaptation pathways, and predicted that stress adaptation involves more systems than the HPA-axis alone. This mini-review aims to summarize our recent data and research by ot...
journal_title:General and comparative endocrinology
pub_type: 杂志文章,评审
doi:10.1016/j.ygcen.2007.04.005
更新日期:2007-08-01 00:00:00
abstract::The present investigation was designed to (1) determine if atrial natriuretic factor gene expression occurs within invertebrates as well as within vertebrates; (2) determine whether the product of this gene expression is the 126-amino-acid atrial natriuretic factor prohormone or some other molecular species; and (3) e...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1006/gcen.1995.1133
更新日期:1995-10-01 00:00:00
abstract::Seabird productivity is shaped by marine resource availability. We examined the link between seabird productivity and an indirect measure of food availability: baseline plasma corticosterone. We predicted low productivity would coincide with elevated baseline corticosterone levels in Black-legged Kittiwakes (Rissa tri...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2006.10.011
更新日期:2007-02-01 00:00:00
abstract::This study aimed at investigating the role of sexual steroids in the regulation of the expression of the single aromatase gene and steroid receptor subtypes in the brain-pituitary-ovarian axis of the Japanese eel. Unlike other teleosts, which possess duplicated genes for aromatase, cyp19a1a and cyp19a1b, expressed in ...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2011.11.005
更新日期:2012-01-01 00:00:00
abstract::Primary cultured gill epithelia from goldfish and rainbow trout were used to investigate a role for cortisol in the regulation of paracellular permeability and tight junction (TJ) protein transcript abundance in representative stenohaline versus euryhaline freshwater (FW) fish gills. Glucocorticoid and mineralocortico...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2011.04.023
更新日期:2011-07-01 00:00:00
abstract::The gonadotropins (GTHs) follicle-stimulating hormone (FSH) and luteinizing hormone (LH) are the key regulators of reproduction. We determined the competence of heterologous recombinant GTHs at eliciting steroid secretion from carp ovaries at different reproductive stages. We collected carp ovaries at: early, mid and ...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2012.04.002
更新日期:2012-08-01 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::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
pub_type: 杂志文章
doi:10.1016/0016-6480(89)90008-7
更新日期:1989-07-01 00:00:00
abstract::Ecdysteroids play an essential role in the regulation of the molting processes of arthropods. Nuclear receptors of the spider Agelena silvatica that showed high homology with other arthropods especially in the functional domains were identified, two isoforms of ecdysone receptor (AsEcRA, AsEcRB), retinoid X receptor (...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2017.01.032
更新日期:2017-06-01 00:00:00
abstract::Fecal steroid analysis is an increasingly common non-invasive technique used in both captive and field studies to measure an animal's approximate hormonal levels and corresponding physiological state. Fecal collection in the field necessitates storage and transportation methods that will prevent the degradation of hor...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2006.06.010
更新日期:2007-01-01 00:00:00
abstract::Two types of cDNAs (GTH-I beta and -II beta) that encode the beta subunit of goldfish gonadotropin were cloned from a goldfish pituitary cDNA library. The nucleotide sequence of GTH-I beta cDNA was 616 bp long, encoding 130 amino acids, and that of GTH-II beta was 552 bp long, encoding 140 amino acids. These two types...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1006/gcen.1996.6839
更新日期:1997-03-01 00:00:00
abstract::Corticosterone, progesterone, estradiol-17 beta, and estrone were quantified in plasma collected weekly (April-September) from renesting and nonlaying female American kestrels (Falco sparverius) paired with males in captivity. Hormone levels and body weights for laying females were maximal during courtship and egg-lay...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/0016-6480(86)90048-1
更新日期:1986-06-01 00:00:00
abstract::This experiment was performed on two groups of male Japanese quail. One had been maintained in our laboratory as a closed colony (S-group), and the other had been obtained from a commercial source (R-group). Different responses of gonadal function were found between two groups following either testosterone treatment o...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/0016-6480(85)90390-9
更新日期:1985-09-01 00:00:00
abstract::Testosterone has been suggested to be involved in the regulation of male territorial behavior. For example, seasonal peaks in testosterone typically coincide with periods of intense competition between males for territories and mating partners. However, some species also express territorial behavior outside a breeding...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2012.11.027
更新日期:2013-04-01 00:00:00