Abstract:
:The administration of arginine vasotocin (AVT) to gravid snapping turtles with steroidogenically active corpora lutea and high plasma progesterone concentration (1480 +/- 155 pg/ml) did not trigger oviposition, whereas 12 days after ovulation when luteolysis occurred and plasma progesterone concentration was low (570 +/- 78 pg/ml), treatment with AVT caused oviposition. Controls with high plasma progesterone concentration (1605 +/- 185 pg/ml) oviposited 15-23 days after ovulation when plasma progesterone concentration dropped to 201 +/- 35 pg/ml. Deluteinization-induced oviposition was initiated 15 hr after surgery and was completed by 30 hr. Oviposition of complete clutches occurred and was correlated with a significant drop in plasma progesterone. Sham-operated turtles did not exhibit oviposition and no significant change in progesterone concentration was observed. A single injection of prostaglandin F2 alpha (PGF) in recently ovulated turtles induced early luteolysis and a significant decrease in plasma progesterone concentration after 24-30 hr. A single administration of PGF caused the disappearance of steroidogenic features such as the smooth endoplasmic reticulum and mitochondria with tubular cristae 48 hr later. Also PGF triggered the invasion of a hyaline-like material from the luteal theca into the luteal cell mass which eventually induced luteolysis. The role of AVT, PGF, and progesterone in relation to egg retention and oviposition is discussed.
journal_name
Gen Comp Endocrinoljournal_title
General and comparative endocrinologyauthors
Mahmoud IY,Cyrus RV,McAsey ME,Cady C,Woller MJdoi
10.1016/0016-6480(88)90052-4subject
Has Abstractpub_date
1988-01-01 00:00:00pages
56-64issue
1eissn
0016-6480issn
1095-6840journal_volume
69pub_type
杂志文章abstract::In goldfish, two endogenous gonadotropin-releasing hormones (GnRH), salmon GnRH (sGnRH) and chicken GnRH-II (cGnRH-II), are thought to stimulate growth hormone (GH) release via protein kinase C (PKC) and subsequent increases in intracellular Ca(2+) levels ([Ca(2+)](i)). In contrast, the signaling mechanism for seroton...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2008.07.021
更新日期:2008-10-01 00:00:00
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journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/0016-6480(85)90260-6
更新日期:1985-02-01 00:00:00
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journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/0016-6480(92)90018-f
更新日期:1992-08-01 00:00:00
abstract::cDNA encoding the beta type of thyroid hormone receptor (THR) was cloned from a lambda gt10 library prepared from the whole bodies of metamorphosing flounder (Paralichthys olivaceus). The deduced amino acid sequence of the flounder THR beta (fTHR beta 1) showed higher homologies to the known THR beta s of other verteb...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1006/gcen.1995.1102
更新日期:1995-08-01 00:00:00
abstract::To understand the effect of testosterone on sex differentiation, the quantities of testosterone (T) and estradiol-17beta (E2) in developing eggs of medaka (Oryzias latipes) were measured by radioimmunoassay, and the influence on sex differentiation of treating embryos with exogenous androgens was also examined. Endoge...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2005.07.003
更新日期:2006-01-01 00:00:00
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journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/0016-6480(85)90136-4
更新日期:1985-04-01 00:00:00
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journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2008.08.008
更新日期:2008-11-01 00:00:00
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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
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journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1006/gcen.1993.1179
更新日期:1993-12-01 00:00:00
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journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2010.10.009
更新日期:2011-01-15 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::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::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::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
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journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/0016-6480(91)90063-c
更新日期:1991-10-01 00:00:00
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journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2007.02.006
更新日期:2007-05-01 00:00:00
abstract::The effect of thyrotropin releasing hormone (TRH) administered intramuscularly (im) on serum levels of prolactin (Prl) in ovariectomized (ovx) adult turkeys before and following the onset of photostimulation, before and during daily administration (im) of progesterone (P; 0.1, 0.4, or 1.0 mg/kg), estradiol benzoate (E...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/0016-6480(86)90101-2
更新日期:1986-04-01 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::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
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journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/0016-6480(91)90183-7
更新日期:1991-05-01 00:00:00
abstract::Leptin plays key roles in body weight regulation, energy metabolism, food intake, reproduction and immunity in mammals. However, its function in teleosts is still unclear. In the present study, two leptin genes (gLepA and gLepB) and one leptin receptor gene (gLepR) were cloned and characterized in orange-spotted group...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2012.09.008
更新日期:2013-01-15 00:00:00
abstract::A highly specific and homologous radioimmunoassay (RIA) for the measurement of prolactin (PRL) in the plasma and the pituitary of the eel was developed using a rabbit antiserum to eel PRL. PRL was purified from the pituitary of Japanese eel (Anguilla japonica). Pituitary extracts and plasma from the Japanese and Europ...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/0016-6480(91)90167-5
更新日期:1991-03-01 00:00:00
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. H...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/0016-6480(86)90134-6
更新日期:1986-09-01 00:00:00
abstract::Plasma concentrations of stress hormones [adrenaline (ADR), noradrenaline (NR)], lactate, glucose and CO2 were monitored during peak nesting period (May-October) at different phases of nesting in the green turtle, Chelonia mydas. These include, emergence from sea, excavating body and nest chambers, oviposition, coveri...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2007.09.012
更新日期:2008-02-01 00:00:00
abstract::In insects, especially phytophagous insects, feeding behavior occurs at a regular frequency. Although a number of physiological studies have revealed various causal factors leading to feeding behavior in insects, little has been demonstrated regarding the regulatory mechanisms underlying insect feeding behavior. To co...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2011.03.004
更新日期:2011-05-15 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::The presence of binding sites for nonecdysteroid steroids was investigated in the cytosol of several tissues of the migratory locust, Locusta migratoria migratorioides. Binding of androgens was not observed. Most tissues, however, showed nonsaturable binding of estrogens and in some tissues saturable progestin binding...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/0016-6480(88)90162-1
更新日期:1988-12-01 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::Comparative hormone studies can reveal how physiology underlies life history variation. Here, we examined seasonal variation in plasma testosterone concentration between populations of male orange-crowned warblers (Vermivora celata) breeding in Fairbanks, Alaska (V. c. celata) and on Santa Catalina Island, California ...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/j.ygcen.2010.04.019
更新日期:2010-09-15 00:00:00
abstract::Subcutaneous daily injections of ovine prolactin (PRL) inhibit photoperiodic induction of gonads and fattening in the female redheaded bunting (Emberiza bruniceps). However, birds respond to the same photoperiod (15L:9D) after withdrawal of the exogenous PRL. Further, PRL injections given in late hours during the subj...
journal_title:General and comparative endocrinology
pub_type: 杂志文章
doi:10.1016/0016-6480(83)90127-2
更新日期:1983-11-01 00:00:00