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Showing papers in "General and Comparative Endocrinology in 1979"


Journal ArticleDOI
TL;DR: It seems that the adrenal glands have a more important role in the production and secretion of testosterone than the testes or the ovary in the embryonic chicks, and that the embryonic testes are less active than the embryonic ovary for the production of testosterone and estradiol.

156 citations


Journal ArticleDOI
TL;DR: Oral administration of massive doses of methyltestosterone into goldfish caused an extensive proliferation of the rough endoplasmic reticulum, hypertrophy of the Golgi apparatus, and the production of numerous secretory granules in the liver, suggesting the induced synthesis of some secretory proteins.

141 citations


Journal ArticleDOI
TL;DR: In certain incubates with less mature oocytes (denoted by germinal vesicle position) ovulation occurred prior to GVBD, and there was a lower steriod concentration that induced GV BD without ovulation by 48 hr.

138 citations


Journal ArticleDOI
TL;DR: The role of the gonad with respect to the sexual development of the immature pituitary gland is discussed in this article, where the authors show that intra-itoneal administration of testosterone promotes the appearance of gonadotropin in juvenile male and female rainbow trout.

127 citations


Journal ArticleDOI
TL;DR: Evidence of a somatostatin (SRIF)-like antigen has been found in the brain and digestive tract of rainbow trout and in the gut, where material immunoreactive for luteinizing hormone-releasing hormone has the same distribution in the pituitary as SRIF.

124 citations


Journal ArticleDOI
TL;DR: The periovulatory pattern of circulating gonadotropin is described for the first time in a poikilothermic vertebrate and indicates that the goldfish provides a valuable model for the study of ovulation in teleosts.

120 citations


Journal ArticleDOI
TL;DR: Thyroxine (T4) was measured by double antibody radioimmunoassay in blood serum and pericardial fluid of individual tadpoles and frogs of Rana catesbeiana to show a general developmental pattern and some individual animals at each stage, including metamorphic stages, were below the limit of detection.

111 citations


Journal ArticleDOI
TL;DR: Data suggest that the secretion of FSH and LH may be regulated independently; and, contrary to existing physiological data, these two gonadotropins may have distinctive roles in ovarian regulation that differ from those suggested by hormone therapy studies.

110 citations


Journal ArticleDOI
TL;DR: The two salmon vitellogenic Con AI hormones displayed numerous prominent differences in amino acid and carbohydrate compositions from, and were immunologically remote from, the salmon maturational Con AII hormone.

106 citations


Journal ArticleDOI
TL;DR: There seems to be in the central nervous system of some invertebrates, peptides that have similar immunoreactive groups to the morphinomimetic peptides recently discovered in the vertebrate hypophysis or encephalon.

100 citations


Journal ArticleDOI
TL;DR: It is suggested that metabolic changes at the pituitary level may play some role in the induction of the increased responsiveness to luteinizing hormone-releasing hormone which can be observed in quails after exposure to 7 long days.

Journal ArticleDOI
TL;DR: The turkey LH purified here had significantly higher carbohydrate content than a previous preparation of turkey LH, and it is suggested that the evolution of the structure of active sites in turkey LH has involved convergence on those of the FSH molecule.

Journal ArticleDOI
TL;DR: The evidence as a whole suggests that MCH is an hypothalamic secretion which is stored and released by the neurohypophysis.

Journal ArticleDOI
TL;DR: In adult female locusts, direct measurements of AKH (adipokinetic hormone) in the haemolymph suggest that release of hormone does not occur at a constant rate during flight.

Journal ArticleDOI
TL;DR: It appears that the loss of clutch or nestlings somehow suppresses or removes an inhibitory function that normally decreases secretion of LH and sex hormones at this time, and the mechanisms that delay the onset of molt and decrease its duration are not known.

Journal ArticleDOI
TL;DR: Concentration of growth hormone (GH) and prolactin were measured in plasma from embryonic and neonatal chicks as mentioned in this paper, but GH was not detectable in these chicks and was found to be a marker of fertility.

Journal ArticleDOI
TL;DR: It is reported that the syringeal muscles of zebra finches and canaries have specific high-affinity androgen binding proteins that are far in excess of those demonstrated to exist in any other striated muscle and within the range of values observed for classical androgen-sensitive tissues such as the mouse kidney.

Journal ArticleDOI
TL;DR: With the use of these RIA's, progesterone and estrone were demonstrated in the ovaries and pyloric ceca of single specimens of Asterias rubens, and of the differences in the steroid levels between both organs will be discussed.

Journal ArticleDOI
TL;DR: The heterogeneity of avian pituitary LH was shown by means of isoelectric focusing and gel filtration studies coupled with radioimmunoassay, which indicated the presence of an LH with a molecular weight of 23,500–25,000 together with a component having double the molecular weight.


Journal ArticleDOI
TL;DR: It is demonstrated that, in frogs, output of aldosterone is two times higher than output of corticosterone, and the ald testosterone-corticosterone ratio is even larger after stimulation by high doses of ACTH.

Journal ArticleDOI
TL;DR: In this paper, Asn1-Val5 angiotensin II amide (AII) was injected into water-replete eels in fresh water elicited drinking within a few minutes after the injection.

Journal ArticleDOI
TL;DR: It is concluded that Stannius corpuscles contain an acid-stable hypocalcemic factor which exerts its effect on calcium homeostasis by directly attenuating the rate of branchial calcium influx.

Journal ArticleDOI
TL;DR: Tortoise pineal serotonin and melatonin levels show marked circadian and circannual rhythms in a natural environment and the physiological significance of these rhythms remains to be determined and needs further investigation.

Journal ArticleDOI
TL;DR: Observations suggest that AII has become adaptively involved in the physiological mechanisms inducing thirst during the evolutionary process and Evolution of receptive sites for AII in the brain is discussed in vertebrates.

Journal ArticleDOI
TL;DR: It is suggested that more than one functional form of gill (Na + +K + )ATPase exists, and that these vary in activity with external salinity, and the response of branchial ATPase to this antibiotic depends on the environment.

Journal ArticleDOI
TL;DR: An immunocytochemical unlabeled antibody enzyme technique has been applied to localize mammalian-like immunoreactive luteinizing hormone-releasing hormone (ir-LH-RH) in central nervous tissue of Pacific lamprey (Entosphenus tridentata; anadromous spawning migrants) and of Pacific hagfish (Eptatretus stouti, sexually undifferentiated and mature) as discussed by the authors.

Journal ArticleDOI
TL;DR: The localization of the different trophic hormone-producing cells, however, agreed with the findings available in the literature and it seems to be reasonable to accept that the first signs of PRL secretion appear on the sixth day of incubation.

Journal ArticleDOI
TL;DR: In intact ducks the increasing testosterone levels in winter and spring appear to depress the thyroid while the annual peak in thyroxine secretion in June may act as an essential (primary?) factor in causing the cessation of the reproductive season.

Journal ArticleDOI
TL;DR: For example, Oncopeltus fasciatus was exposed to precocene II for different times as larvae or adults, and the inactivation of the corpora allata resulted in precocious metamorphosis and degeneration of the prothoracic glands in younger larval instars and inhibition of vitellogenesis in adult females.