Journal ArticleDOI
Further evidence for reciprocal interactions between the annual sexual and thyroid cycles in male Peking ducks.
TLDR
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.About:
This article is published in General and Comparative Endocrinology.The article was published on 1979-01-01. It has received 66 citations till now.read more
Citations
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Journal ArticleDOI
The hypothalamic-pituitary-thyroid (HPT) axis in birds and its role in bird development and reproduction.
TL;DR: Thyroid function and its hypothalamic-pituitary-thyroid (HPT) axis control in birds is reviewed with emphasis on the similarities and differences in thyroid function compared to mammals and other vertebrate classes.
Journal ArticleDOI
Role of the thyroid gland in seasonal reproduction: thyroidectomy blocks seasonal suppression of reproductive neuroendocrine activity in ewes.
TL;DR: The hypothesis that the thyroid is necessary for endogenous suppression of neuroendocrine mechanisms that generate LH pulses, a suppression crucial for the transition to anestrus, is tested.
Journal ArticleDOI
Seasonal Changes in the Behavior and Plasma Titers of Various Hormones in Barheaded Geese, Anser indicus
TL;DR: A number of behavioral and physiological parameters including the circulating levels of 7 hormones were investigated in a free ranging population of barheaded geese in Seewiesen, W. Germany to examine whether the annual changes in the frequencies of various behaviors were related to changes in circulating hormonal concentrations.
Journal ArticleDOI
Role of the thyroid gland in seasonal reproduction. II. Thyroxine allows a season-specific suppression of gonadotropin secretion in sheep.
TL;DR: The concept that the thyroid gland plays a fundamental role in seasonal reproduction in the ewe is supported for an endogenously generated change in the neuroendocrine axis that leads to an intensified E negative feedback and an end to the breeding season.
Journal ArticleDOI
Seasonal cycles in testicular activity, gonadotropin, and thyroxine in the painted turtle, Chrysemys picta, under natural conditions
TL;DR: The profile in plasma FSH is consistent with the view that this gonadotropin may regulate androgen secretion but it did not show the expected relationship to the spermatogenetic cycle.
References
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Journal ArticleDOI
A radioimmunoassay for avian luteinizing hormone.
Journal ArticleDOI
The effect of thyroidectomy on testicular size and on the photorefractory period in the starling (Sturnus vulgaris L.)
TL;DR: Thyroidectomy of Starlings prior to exposure to long photo-periods (17L:7D) resulted in a failure of testes to regress after an initial size increase, and thyroidectomy after four weeks of exposure resulted in testicular regression followed by a second period of size increase.
Journal ArticleDOI
A comparative study of the annual cycles in sexual and thyroid function in male Peking ducks (Anas platyrhynchos) and teal (Anas crecca)
TL;DR: Experimental studies on teal and ducks kept in bioclimatic chambers have shown the stimulatory effect of long days on gonadotrophin secretion in teal as in ducks, and the inhibitory effect of cold on sexual function.
Journal ArticleDOI
Plasma levels of luteinizing hormone in gonadectomized Japanese quail exposed to short or to long daylengths.
TL;DR: Exposure to long days increased LH levels and in the gonadectomized quail LH continued to rise over several weeks, concluding that the photoperiodic regulation of LH secretion does not operate solely by adjusting sensitivity to gonadal feedback, but works in a more direct manner.
Journal ArticleDOI
Plasma and pituitary luteinizing hormone in intact and castrated tree sparrows (Spizella arborea) during a photoinduced gonadal cycle
Fred E. Wilson,Brian K. Follett +1 more
TL;DR: It is concluded that testicular steroids are not obligatory determinants of the temporal pattern of circulating LH in photostimulated males, yet they apparently inhibit the photoresponsive hypothalamohypophysial axis and the testes in nonphotostimulation males.
Related Papers (5)
Influences of thyroidectomy and thyroxine replacement on photoperiodically controlled reproduction in quail
B. K. Follett,T. J. Nicholls +1 more