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 in viviparous (live-bearing) reptiles. As a first step towards understanding the functions of aromatase during gestation in viviparous reptiles, we measured aromatase activity in maternal and embryonic tissues at three stages of gestation in the viviparous skink, Niveoscincus metallicus. Maternal ovaries and adrenals maintained high aromatase activity throughout gestation. During the early phases of embryonic development, placental aromatase activity was comparable to that in maternal ovaries, but declined significantly at progressive stages of gestation. Aromatase activity in the developing brains and gonads of embryos was comparable with measurements in oviparous reptiles. Aromatase activity in the developing brains peaked mid development, and declined to low levels in late stage embryos. Aromatase activity in the embryonic gonads was low at embryonic stage 29-34, but increased significantly at mid-development and then remained high in late stage embryos. We conclude that ovarian estrogen synthesis is supplemented by placental aromatase activity and that maternal adrenals provide an auxiliary source of sex steroid. The pattern of change in aromatase activity in embryonic brains and gonads suggests that brain aromatase is important during sexual differentiation, and that embryonic gonads are increasingly steroidogenic as development progresses. Our data indicate vital roles of aromatase in gestation and development in viviparous lizards.
journal_name
Gen Comp Endocrinoljournal_title
General and comparative endocrinologyauthors
Parsley LM,Wapstra E,Jones SMdoi
10.1016/j.ygcen.2014.02.020subject
Has Abstractpub_date
2014-05-01 00:00:00pages
61-6eissn
0016-6480issn
1095-6840pii
S0016-6480(14)00072-0journal_volume
200pub_type
杂志文章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：:The insulin/PI3K/Akt signaling pathway is strongly involved in the differentiation of C2C12 cells, as has been demonstrated by the addition of IGFs and insulin to culture media. In this study, we have characterized the role of insulin in chick myoblast proliferation and differentiation in vitro and in vivo, and have r...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1016/j.ygcen.2011.11.043
更新日期：2012-02-01 00:00:00
abstract：:The effects of serotonin (5-HT) on gonadotropin and growth hormone release from perifused goldfish (Carassius auratus, L.) pituitary glands were studied. Serotonin, at micromolar concentrations, caused a dose-related release of gonadotropin and an inhibition of growth hormone release in pituitaries from goldfish at di...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1016/0016-6480(91)90301-l
更新日期：1991-04-01 00:00:00
abstract：:Proopiomelanocortin (POMC) is a common precursor of adrenocorticotropic hormone (ACTH), melanophore-stimulating hormone (MSH), and endorphin (END). In pituitary gland, POMC receives posttranslational processing by which different peptides are generated in the pars distalis (PD) and pars intermedia (PI). Recently, we c...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1016/j.ygcen.2005.09.005
更新日期：2006-02-01 00:00:00
abstract：:To quantify the renal excretion of arginine vasotocin (AVT) in birds, synthetic AVT was infused into conscious Pekin ducks at rates of 0.03, 0.10, and 0.30 ng/kg/min for 30 min and the relationships between plasma and urine AVT concentrations were monitored by radioimmunoassay. As plasma AVT concentrations increased (...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1006/gcen.1995.1090
更新日期：1995-07-01 00:00:00
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
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：:Almost all physiological processes within the organism, including immune parameters and hormones, follow a circadian rhythm. These daily fluctuations are often observed in free-living organisms; however, little is known regarding hormonal and immune daily variations in anurans, particularly under laboratory conditions...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1016/j.ygcen.2020.113702
更新日期：2020-12-20 00:00:00
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：:Galanin is a multi-functional neuropeptide that is widely distributed in the mammalian central nervous system and peripheral tissues. It exerts multiple physiological functions through interaction with 3 known G protein-coupled receptors (GPCR), namely, galanin type I, II and III (GalR1, 2 and 3) receptors, which have...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1016/j.ygcen.2010.10.011
更新日期：2011-01-15 00:00:00
abstract：:Follicle-stimulating hormone (FSH), a glycoprotein consisting of an alpha subunit and a unique beta subunit, is essential for gonadal development and function in vertebrates including teleosts. FSH is regulated by a variety of neuroendocrine and endocrine factors, and its biosynthesis is primarily determined by the ex...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1016/j.ygcen.2004.10.019
更新日期：2005-03-01 00:00:00
abstract：:In the genetic sex determination of vertebrates, the gonadal sex depends on the combination of sex chromosomes that a zygote possesses. Despite the discovery of the sex-determining gene (SRY/Sry) in mammals in 1990s, the sex-determining gene in non-mammalian vertebrates remained an enigma for over a decade. In most ma...
journal_title：General and comparative endocrinology
pub_type： 杂志文章,评审
doi：10.1016/j.ygcen.2015.10.004
更新日期：2016-12-01 00:00:00
abstract：:The activities of oxidative enzymes of hepatic mitochondria of Anabas testudineus increased following exogenous administration of hydrocortisone and corticosterone. The inhibitors of protein synthesis prevented the hormone-mediated increase of hepatic enzymes, suggesting that corticosteroids regulate the oxidative met...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1016/0016-6480(90)90017-g
更新日期：1990-05-01 00:00:00
abstract：:Effects of growth hormone (GH) on the synthesis of mucopolysaccharide by ceratobranchial cartilages of the Japanese eel, Anguilla japonica, were examined by monitoring the in vitro uptake of [35S]sulfate. The [35S]sulfate uptake decreased rapidly to one-third of the initial level during the first 3 days after hypophys...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1016/0016-6480(90)90117-5
更新日期：1990-08-01 00:00:00
abstract：:A gonadotropin-releasing hormone (GnRH) agonist, d-Trp6-LHRH, was evaluated for its effectiveness in reducing circulating testosterone concentrations in wild Hawaiian monk seals (Monachus schauinslandi). Twenty-eight adult male seals were randomly divided into three groups: 10 were captured and treated with 7.5 mg of ...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1006/gcen.1998.7173
更新日期：1998-11-01 00:00:00
abstract：:Rainbow trout were confined for 48 hr, during which time water quality either was allowed to deteriorate (resulting in elevated NH3, elevated free CO2, and reduced dissolved O2) or was maintained at preconfinement levels. Fish were removed and blood samples taken at 0, 2, 4, 8, 24, and 48 hr after the onset of confine...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1016/0016-6480(92)90240-k
更新日期：1992-12-01 00:00:00
abstract：:Reptilia is the only vertebrate class in which cDNA for the gonadotropin beta subunit precursor molecule has not been cloned. We have isolated the full-length cDNA clone encoding the LH beta subunit precursor molecule and a partial cDNA clone encoding the FSH beta subunit precursor molecule from a pituitary cDNA libra...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1016/s0016-6480(03)00103-5
更新日期：2003-07-01 00:00:00
abstract：:Androgens take part in the regulation of puberty and promote growth and development. They play their biological role by binding to a specific androgen receptor (AR). The aim of this study was to evaluate the expression of AR mRNA and protein in the pituitary and adrenal glands, to localize AR protein in luteinizing ho...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1016/j.ygcen.2015.03.001
更新日期：2015-06-01 00:00:00
abstract：:Seasonally spawning fish rely on a dynamic and complex hormonal interplay to regulate cycles of gonadal development and the regression. Thyroid hormones have been shown to be a key player during gonadal development, and can regulate the activity of a number of essential reproductive hormones. Apoptosis is a vital cell...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1016/j.ygcen.2019.113382
更新日期：2020-04-01 00:00:00
abstract：:Pancreatic polypeptide (PP) has been isolated from pancreatic extracts of the herring gull (Larus argentatus) using a radioimmunoassay employing an antiserum (PP 221), generated to the conserved C-terminal hexapeptide amide of mammalian PP. Gel permeation and reverse-phase HPLC fractionation of crude pancreatic extrac...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1006/gcen.1994.1029
更新日期：1994-02-01 00:00:00
abstract：:In mammals, the rhythmic secretion of melatonin from the pineal gland is driven by the circadian clock in the suprachiasmatic nucleus (SCN) of the hypothalamus. The robust nightly peak of melatonin secretion is an output signal of the circadian clock and is supposed to deliver the circadian message to the whole of the...
journal_title：General and comparative endocrinology
pub_type： 杂志文章,评审
doi：10.1016/j.ygcen.2017.05.013
更新日期：2018-03-01 00:00:00
abstract：:Vitellogenesis in tuatara (Sphenodon punctatus) on Stephens Island, New Zealand, at the southern (coolest) end of the geographical range of this species involves a prolonged period of about 3 years of the average 4-year reproductive cycle. These studies used a semiquantitative electrophoretic assay for vitellogenin (V...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1006/gcen.1994.1117
更新日期：1994-08-01 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：:Laboratory populations of the prairie deermouse (Peromyscus maniculatus) reach a growth asymptote due primarily to the failure of more than 90% of the young born into the population to mature sexually. This inhibition is reversible; when young are removed from the inhibiting influence of the population more than 75% w...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1016/s0016-6480(02)00528-2
更新日期：2002-11-01 00:00:00
abstract：:High-affinity, limited-capacity, 3,5,3'-triiodo-L-thyronine (T3)-binding sites were established by in vitro saturation analysis in cell nuclei of the pituitary gland of arctic charr. The sites were extracted from the purified nuclei using 0.4 M NaCl and incubated with [125I]T3 in the presence of 0.2 M NaCl. T3 saturab...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1016/0016-6480(90)90202-w
更新日期：1990-01-01 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：: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
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 paper describes neuropeptide Y-like-immunoreactive (NPY-ir) structures in the brain of the spotted gar, Lepisosteus oculatus, with special regard to their anatomical relations to gonadotropin-releasing hormone (GnRH)-ir structures in the hypothalamus and the terminal nerve (TN). NPY-ir cells were found in ...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1016/j.ygcen.2005.02.010
更新日期：2005-07-01 00:00:00
abstract：:In vivo studies were carried out in adult chickens in an attempt to evaluate the effectiveness of somatostatin (SRIF) in regulating hormone secretion from the splenic pancreatic lobe after 99% of the pancreatic mass was surgically ablated. Sixteen days after either sham operation or 99% pancreatectomy, birds were infu...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1016/0016-6480(86)90166-8
更新日期：1986-08-01 00:00:00
