Abstract:
:The titer of moulting hormones (ecdysteroids) in fifth instar male Rhodnius displays a gradual decline throughout the week preceding ecdysis when animals are maintained in constant light (LL). Multiple sampling of haemolymph from the same animal reveals a constant rate of decline with no increases in titer observed. However, 20-hydroxyecdysone (20HE) provokes increases in the titer of ecdysteroids which occur between 18 and 27 hr after injection. Multiple injections of 20HE provoke regular changes in the rate of decline of the titer. When 20HE is injected into animals reared in LL, a rhythm in the titer of ecdysteroids with an initial periodicity of approximately 28 hr is provoked which is reduced to 24 hr by 72-96 hr after injection. Injection of antiserum to ecdysteroids elicits an immediate rapid oscillation in titer similar to that observed in light/dark (L/D) cycles. Therefore injections of 20HE or antiserum to ecdysteroids can provoke a rhythm in the titer of ecdysteroids in animals reared in LL. Rhythms in ecdysteroid titer would appear to result from the interactions of synthetic and catabolic systems, both of which would appear to be able to act in a timed fashion. Such rhythmic modulation of ecdysteroid titer may provide time cues to the circadian system timing ecdysis. Thus the gated ecdysis rhythm observed after 20HE or antiserum injections may be a response to induced modulation of the ecdysteroid titer.
journal_name
Gen Comp Endocrinoljournal_title
General and comparative endocrinologyauthors
Ampleford EJ,Steel CGdoi
10.1016/0016-6480(86)90134-6subject
Has Abstractpub_date
1986-09-01 00:00:00pages
353-61issue
3eissn
0016-6480issn
1095-6840journal_volume
63pub_type
杂志文章abstract::A growing number of studies have examined transcriptional responses to sex steroids along the hypothalamic-pituitary-gonadal axis in teleost fishes. However, data are lacking on the molecular cascades that underlie progesterone signaling. The objective of this study was to characterize the transcriptional response in ...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2013.06.008
更新日期:2013-10-01 00:00:00
abstract::Bicuspid teeth are a morphological characteristic in adult metamorphosed urodeles. However, during the mating season the males of many species of plethodontid salamanders (Urodela, Plethodontidae) from northern America bear large monocuspid teeth on their jaws. Since androgen levels are elevated during the mating seas...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/s0016-6480(03)00216-8
更新日期:2003-10-15 00:00:00
abstract::Dabry's sturgeon (Acipenser dabryanus Dumeril, 1868) belongs to Sturgeon and is distributed throughout the mainstream of the upper Yangtze River. While there is little research onphysiological mechanism of Dabry's sturgeon, such as feeding regulation by the CRF system. At present, CRF is thought to regulate feeding vi...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2019.05.005
更新日期:2019-09-01 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::The presence of a robust estrogen (E2) response system throughout heart and blood vessel tissues of vertebrates, including humans, has led to the speculation that this ubiquitous hormone may play a prominent role in the health and maintenance of the adult cardiovascular system (CVS). We previously established an embry...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2013.04.016
更新日期:2013-08-01 00:00:00
abstract::Estrogen signalling is critical for ovarian differentiation in reptiles with temperature-dependent sex determination (TSD). To elucidate the involvement of estrogen in this process, adrenal-kidney-gonadal (AKG) expression of estrogen receptor (ERα) was studied at female-producing temperature (FPT) in the developing em...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2014.08.003
更新日期:2015-09-01 00:00:00
abstract::In recent years, invertebrate peptides have been identified which share substantial homologies with vertebrate insulin and insulin-like growth factors (IGFs), indicating a high degree of conservation of insulin/IGF systems through animal evolution. In a previous study, we provided evidence for the presence of IGF-I-li...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1006/gcen.1996.6824
更新日期:1997-03-01 00:00:00
abstract::High levels of the amino acid neurotransmitter glutamate were found in the goldfish hypothalamus and pituitary using high performance liquid chromatography with fluorometric detection. A specific polyclonal antibody to glutamate was generated in the rabbit for immunocytochemistry. Localization studies demonstrated tha...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1006/gcen.1996.0103
更新日期:1996-08-01 00:00:00
abstract::Fecal glucocorticoid metabolite (FGM) analysis has received considerable attention in conservation biology because it has potential to be used as a noninvasive measure of stress in animals. There has been a recent and extensive literature describing the importance of technical, physiological, and biological validation...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2008.05.001
更新日期:2008-08-01 00:00:00
abstract::When pigeons were injected with an extract of chicken hypothalamus, the increase in weight of the crop sac showed that prolactin secretion was stimulated. Crop sac weight was no higher after 16 days of injection than it was after 8 days. Pituitary gland content of prolactin and growth hormone was elevated at 8 days, b...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/0016-6480(84)90106-0
更新日期:1984-08-01 00:00:00
abstract::Saline extracts of the corpus cardiacum (CC) of Locusta migratoria activate glycogen phosphorylase in locust fat body. The response of phosphorylase to CC extracts and to synthetic adipokinetic hormone (AKH) suggests that the factor responsible for the activating effect of the CC on phosphorylase is AKH, supplemented ...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/0016-6480(83)90222-8
更新日期:1983-05-01 00:00:00
abstract::In in vivo experiments injection of dopamine (DA) or leucine enkephalin (L-Enk) produced hypoglycemia in intact red swamp crayfish, Procambarus clarkii. In contrast, neither compound had a significant effect on the circulating glucose concentration in eyestalkless individuals. With intact crayfish spiperone, a DA rece...
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
abstract::Prolonged or frequent secretion of adrenal glucocorticoids in response to aversive stimuli can negatively impact reproduction. Because female southern white rhinoceros (Ceratotherium simum simum) reproduce poorly in captivity, we compared fecal corticosterone metabolite concentrations among parous, nulliparous, and ad...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2011.02.010
更新日期:2011-05-01 00:00:00
abstract::To study the expression of four estrogen receptor genes (erα1, erα2, erβ1, erβ2) of female rainbow trout (Oncorhynchus mykiss) during first ovarian development, trouts were sampled from different ovarian stages. Serum E2 (estradiol) was measured by ELISA and estrogen receptors mRNA expression were examined by qRT-PCR....
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2017.10.001
更新日期:2018-04-01 00:00:00
abstract::Due to global and local climate changes, farmed salmon may experience periods of elevated sea temperatures. An experiment was conducted to examine endocrine and dietary effects of high sea temperatures in adult (2.0 kg) and sexually immature Atlantic salmon, Salmo salar L. Groups of salmon were exposed to 19 °C while ...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2011.10.007
更新日期:2012-01-01 00:00:00
abstract::Enriched environmental condition (EC) has been known to reduce anxiety. In this study, we examined whether an EC could enhance anxiolytic behavior in the Indian field mouse Mus booduga by down-regulating the expression of glucocorticoid receptor (GR) through microRNA-124a. Wild individuals were captured at agricultura...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2014.01.005
更新日期:2014-04-01 00:00:00
abstract::The renal roles of physiologically relevant doses of angiotensin II (Ang II) and C-type natriuretic peptide (CNP) were investigated in the dogfish, Scyliorhinus canicula, using an in situ perfused trunk preparation. Perfusion with 10(-9) M Ang II resulted in a glomerular antidiuresis and decreases in perfusate flow ra...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2005.08.002
更新日期:2006-01-15 00:00:00
abstract::Pregnant female spiny dogfish were captured off the coasts of Maine and Massachusetts and morphometric and gravimetric analyses of the liver, gonad, and reproductive tract correlated with the reproductive cycle. Plasma samples were taken and circulating steroids (progesterone, testosterone, and estradiol) were measure...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/0016-6480(87)90266-8
更新日期:1987-05-01 00:00:00
abstract::Birds face many challenges during seasonal migrations and must make important decisions about whether to accelerate, maintain, or delay travel to their final destinations. Spring migration is likely more challenging than autumn migration as spring journeys are completed more quickly and weather conditions are harsher ...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2019.04.008
更新日期:2019-09-01 00:00:00
abstract::The role of stress in the decline of Steller sea lions has become of interest in the identification of factors leading to their drastic decline and subsequent failure to recover. Serum cortisol was validated as a potential indicator of stress in three sub-populations inhabiting the majority of the Steller sea lions ra...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2009.06.006
更新日期:2010-01-01 00:00:00
abstract::Insulin-like peptides (ILPs) regulate numerous functions in insects including growth, development, carbohydrate metabolism and female reproduction. This paper reports the immunohistochemical localization of ILPs in brain neurons of Rhodnius prolixus and their intimate associations with the brain circadian clock system...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2012.08.018
更新日期:2012-11-01 00:00:00
abstract::Food abundance is closely associated with reproductive readiness in vertebrates. Food scarcity can activate the hypothalamo-pituitary-adrenal axis, decrease sex steroid secretion, and dampen reproductive behavior. However, the mechanisms underlying these transient effects are unclear. Gonadotropin inhibitory hormone (...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2015.03.010
更新日期:2015-05-01 00:00:00
abstract::Although neuropeptide Y (NPY) has been known to influence the release of luteinizing hormone (LH) and growth hormone (GH) from the pituitary gland of teleosts, the NPY receptor subtypes involved in the regulatory processes have not been fully defined. An attempt has been made to study the involvement of NPY Y1 recepto...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2006.05.012
更新日期:2006-11-01 00:00:00
abstract::We studied the hepatic in vitro deconjugation and deiodination of glucuronide (G) and sulfate (S) conjugates of the thyroid hormones (TH) thyroxine (T(4)), 3,5,3'-triiodothyronine (T(3)), and 3,3', 5'-triiodothyronine (rT(3)) in trout. These conversions have not been studied in nonmammals. Deconjugation of T(4)G, T(3)...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1006/gcen.1999.7326
更新日期:1999-09-01 00:00:00
abstract::The effects of prolonged nutrient restriction (fasting) and subsequent restoration (re-feeding) on the growth hormone (GH)/insulin-like growth factor (IGF) axis were investigated in the tilapia (Oreochromis mossambicus). Mean weight and specific growth rate declined within 1 week in fasted fish, and remained lower tha...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2009.11.012
更新日期:2010-05-01 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
abstract::In fish, luteinizing hormone (LH) stimulates processes leading to final oocyte maturation and ovulation in females, and spermiation in males. The hormone is a heterodimeric glycoprotein composed of two non-covalently associated subunits. In this study, we describe the expression of tilapia LH (tLH) as a biologically a...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2004.10.016
更新日期:2005-02-01 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::The developmental hypothesis proposes that the adrenocortical response to stress during postnatal development in birds should not develop when the benefits of elevated corticosterone do not outweigh the deleterious effects on growth and development. We tested three predictions developed from this hypothesis in free-li...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2010.06.009
更新日期:2010-09-15 00:00:00
abstract::Glucagon plays a pivotal role in the regulation of metabolism. A glucagon receptor has been previously characterized in the frog, Rana tigrina rugulosa, and the frog and human glucagon receptors have been shown to possess similar binding affinities toward human glucagon. To study the structural evolution of glucagon p...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1006/gcen.2001.7697
更新日期:2001-11-01 00:00:00