Abstract：
:We developed and validated a noninvasive method to quantify fecal estrogens and progestins as a tool for monitoring long-term ovarian activity in free-ranging African elephants. The lag times between iv injection of [(3)H]estradiol and [(14)C]progesterone and peak excretion of radioactivity in urine and feces were approximately 4 hr and 48 hr, respectively. The majority of progesterone metabolites recovered was excreted in feces (55%) versus urine (45%), whereas comparatively little of the recovered estradiol metabolites were excreted in feces (5%) compared to urine (95%). Intrasample variation in fecal hormone concentrations was extremely high but could be substantially reduced by extracting well-mixed fecal powder from freeze-dried samples, taken from the central or premixed portion of the wet sample. This method resulted in a close correspondence between matched serum and fecal progestins (mean correlation = 0.81, range 0.61-0.94) collected from five nonpregnant adult females over a 7-month period. Fecal estrogen profiles were more ambiguous, tending to overlap with those of fecal progestins. We conclude that analyses of fecal progestins can provide an effective, noninvasive means of characterizing ovarian activity in free-ranging African elephants.
journal_name
Gen Comp Endocrinoljournal_title
General and comparative endocrinologyauthors
Wasser SK,Papageorge S,Foley C,Brown JLdoi
10.1006/gcen.1996.0067subject
Has Abstractpub_date
1996-05-01 00:00:00pages
255-62issue
2eissn
0016-6480issn
1095-6840pii
S0016-6480(96)90067-2journal_volume
102pub_type
杂志文章abstract：:European silver eels are thought to undergo sexual maturation during their oceanic reproductive migration from the European continent to their spawning area in the Sargasso Sea. Tracking data and various anatomical and physiological features suggest that silver eels migrate in deep sea, leading us to hypothesise that ...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1016/j.ygcen.2007.01.009
更新日期：2007-08-01 00:00:00
abstract：:The present study was designed to investigate potential effects of arachidonic acid (ARA) on the reproductive physiology of female Atlantic cod (Gadus morhua L.). Two-year old Atlantic cod of both sexes were equally distributed into eight sea cages after completion of their first spawning in May 2005. Four experimenta...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1016/j.ygcen.2017.05.020
更新日期：2017-09-01 00:00:00
abstract：:Vasoactive intestinal polypeptide (VIP) is a neuropeptide that has numerous physiological actions and is widely distributed in the body. However, as yet, there is no sequence information about VIP receptors in lower vertebrates. Partial cDNA fragments spanning transmembrane domains 2 to 6 of VIP receptors were isolate...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1006/gcen.1996.6818
更新日期：1997-02-01 00:00:00
abstract：:The effects of a long term partial food restriction were studied in chickens and rats. In chickens the treatment resulted in increased plasma T4 levels while T4 levels in rats remained unchanged. Plasma T3 decreased in both species. In vitro hepatic outer ring deiodinating type I (ORD-I) activity was not influenced by...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1006/gcen.1995.1164
更新日期：1995-12-01 00:00:00
abstract：:Histochemical assays, hormonal quantitation, and steroid biosynthetic studies were carried out with adrenal glands obtained from four stranded whales of two different species (Kogia breviceps and Mesoplodon europaeus), and selected comparisons were made with the results of similar studies of adrenals from terrestrial ...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1016/0016-6480(87)90041-4
更新日期：1987-11-01 00:00:00
abstract：:The regulation of rainbow trout prolactin (PRL) cells by hypothalamic and humoral factors has been investigated. PRL cell activity was assessed using acid gel electrophoresis to measure PRL release in vitro and image analysis to measure PRL cell nuclear area, an index of synthetic activity. 17 beta-oestradiol stimulat...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1006/gcen.1994.1043
更新日期：1994-03-01 00:00:00
abstract：:Intact and radiothyroidectomized male starlings were transferred from short (8-hr) to long (16-hr) day lengths and measurements made of testicular development and of plasma prolactin concentrations. In intact birds the testes reached full maturity within 3 weeks and regressed after 6 weeks of photostimulation, indicat...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1016/0016-6480(84)90179-5
更新日期：1984-05-01 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：:Quantification of glucocorticoid metabolites in feces has been shown to be a powerful tool in evaluating well-being in vertebrates. Little is known however about the hypothalamic-pituitary-adrenal axis response to stressors, and consequent glucocorticoid excretion, in reptiles. In a longitudinal study, fecal corticost...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1016/j.ygcen.2012.02.017
更新日期：2012-05-15 00:00:00
abstract：:To examine the reproductive endocrinology of a large pleuronectiform fish, barfin flounder, Verasper moseri, a promising candidate for aquaculture and resource enhancement in northern Japan due to its high commercial value, three gonadotropin-releasing hormones (GnRHs) in the brain was identified by isolation of their...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1016/s0016-6480(02)00008-4
更新日期：2002-05-01 00:00:00
abstract：:Attractiveness in adult females of Calliphora vomitoria is correlated with ovarian development and there is a marked increase during the previtellogenic and vitellogenic periods. The development of attractiveness may result from the combined actions of ecdysteroids and juvenile hormone. A rise in total hydrocarbons pa...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1016/0016-6480(90)90166-j
更新日期：1990-11-01 00:00:00
abstract：:Changes in the pituitary cells involved in amphibian metamorphosis were studied in Bufo arenarum tadpoles with inhibited thyroid function. After hatching, larvae were treated for 5 months with potassium perchlorate (KClO4), a goitrogenic substance known to prevent absorption of iodine from water or food, resulting in ...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1006/gcen.1995.1057
更新日期：1995-05-01 00:00:00
abstract：:Prolactin-like protein (PRL-L; LOC417800) is a homolog of PRL in non-mammalian vertebrates and can act as a functional ligand of PRL receptor (PRLR). Despite its widespread expression in extrapituitary tissues, mechanisms of regulation of PRL-L in the chicken ovary remain unknown. In this study, we first examined PRL-...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1016/j.ygcen.2016.10.013
更新日期：2017-01-01 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：:Bovine thyroid-stimulating hormone (TSH) was microinjected (0.2 microliter/fish) into prometamorphic flounder larvae and the effects on metamorphosis as well as the tissue thyroxine (T4) and triiodothyronine (T3) levels were studied. After a single injection of TSH (5 mIU/g), the tissue T4 concentration increased mark...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1016/s0016-6480(89)80038-3
更新日期：1989-06-01 00:00:00
abstract：:The tegu lizard Salvator merianae is a large, widely distributed teiid lizard endemic to South America that exhibits annual cycles of high activity during the spring and summer, and hibernation during winter. This pattern of activity and hibernation is accompanied by profound seasonal changes in physiology and behavio...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1016/j.ygcen.2018.06.006
更新日期：2019-03-01 00:00:00
abstract：:The Atlantic Bluefin Tuna (ABFT, Thunnus thynnus) is one of the most intensely exploited fisheries resources in the world. In spite of the years of studies on ABFT, basic aspects of its reproductive biology remain uncertain. To gain insight regarding the seasonal changes of the reproductive characteristics of the east...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1016/j.ygcen.2019.113216
更新日期：2019-10-01 00:00:00
abstract：:Early maternal effects in the form of substances accumulated in the egg, such as carotenoids and hormones, can be physiologically relevant for a good development of offspring. It has been found in different species that testosterone (T) can be beneficial to offspring by increasing growth rate, but detrimental by reduc...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1016/j.ygcen.2007.12.010
更新日期：2008-04-01 00:00:00
abstract：:In teleosts, sex is plastic and is influenced by environmental factors. Elevated temperatures have masculinizing effects on the phenotypic sex of certain sensitive species. In this study, we reared genetic XX Japanese flounder at a high temperature (27.5 ± 0.5 °C) and obtained a population of sex-reversal XX males (ma...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1016/j.ygcen.2018.12.012
更新日期：2019-04-01 00:00:00
abstract：:Urinary excretion of the thyroid hormones (TH) L-thyroxine (T4), and 3,5,3'-triiodo-L-thyronine (T3) and their derivatives was studied in urinary-catheterized rainbow trout (mean wt. 227 g) fasted for 2 days under a 12-hr L:12-hr D photocycle in running water (12 degrees). Catheterized trout were intracardiac-injected...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1006/gcen.1994.1128
更新日期：1994-08-01 00:00:00
abstract：:The effects of epinephrine (E), norepinephrine (NE), phenylephrine (PHE), and isoproterenol (ISO) were studied in vivo on the blood pressure and heart rate of the conscious American bullfrog, Rana catesbeiana. Bullfrogs were chronically cannulated with a T cannula in the right sciatic artery. In warm-acclimated (22 de...
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
abstract：:In vitro experiments were conducted to test the hypothesis that 17alpha,20beta-dihydroxy-4-prengnen-3-one (17,20-P) regulates cortisol metabolism in Pacific salmon. In both rainbow trout and coho salmon, cortisol metabolism was significantly higher in the kidney compared to the liver. The rainbow trout kidney converte...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1016/j.ygcen.2009.06.003
更新日期：2010-01-01 00:00:00
abstract：:Progesterone is believed to have a suppressive or inhibitory role in regulating androgen-dependent sex behaviors in male mammals and birds. Previous studies in this laboratory have revealed that in the little striped whiptail lizard (Cnemidophorus inornatus), progesterone (P) can stimulate sex behavior in a proportion...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1016/0016-6480(92)90125-4
更新日期：1992-04-01 00:00:00
abstract：:Day- and nighttime contents of pineal melatonin and other indoleamines were measured in the Chinese hamster, Cricetulus griseus. The hamsters were inbred in our colony and kept in LD 14:10. Absolute levels of pineal melatonin and N-acetylserotonin contents were extremely low, but showed a significant circadian rhythm ...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1006/gcen.1997.7014
更新日期：1998-01-01 00:00:00
abstract：:The phenomenon of musth is a very stressful event, both behaviorally and physiologically. An ACTH stimulation test was conducted in four adult Asian bull elephants to investigate the possibility that the classical hypothalamic-pituitary-adrenal (HPA) axis is active during musth, resulting in an increase in adrenally p...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1016/j.ygcen.2007.01.029
更新日期：2007-05-01 00:00:00
abstract：:Plasma glucagon levels in 11 different teleosts and in dogfish were evaluated using an adapted classical mammalian radioimmunoassay (RIA). The values obtained are considered relative; sensitivity was inferior to the original method, but the validation experiment results are acceptable. The mean value of the coefficien...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1016/0016-6480(86)90131-0
更新日期：1986-09-01 00:00:00
abstract：:The pineal organ of all vertebrates synthesizes and secretes melatonin in a rhythmic manner due to the circadian rhythm in the activity of arylalkylamine N-acetyltransferase (AANAT) - the rate-limiting enzyme in melatonin synthesis pathway. Nighttime increase in AANAT activity and melatonin synthesis depends on increa...
journal_title：General and comparative endocrinology
pub_type： 杂志文章,评审
doi：10.1016/j.ygcen.2018.07.010
更新日期：2019-08-01 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：:The aim of this work was to study, in the Cebus apella monkey, the developmental changes in the microanatomy of the utero-ovarian ligament (UOL) and whether their vascular and neural elements might be involved in the transfer of signals between the ovaries and uterus. Sections including uterus, UOL, and ovary obtained...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1016/j.ygcen.2005.06.006
更新日期：2005-12-01 00:00:00
abstract：:Molecular cloning of thyrotropin-releasing hormone receptors (TRHR) was performed in a teleost, the sockeye salmon (Oncorhynchus nerka). Four different TRHR cDNAs were cloned and named TRHR1, TRHR2a, TRHR2b and TRHR3 based on their similarity to known TRHR subtypes in vertebrates. Important residues for TRH binding we...
journal_title：General and comparative endocrinology
pub_type： 杂志文章
doi：10.1016/j.ygcen.2011.07.011
更新日期：2011-11-01 00:00:00
