Regulation of Hypothalamic Gonadotropin-Releasing Hormone and Neuropeptide Y Concentrations by Progesterone and Corticosteroids in Immature Rats: Correlation with Luteinizing Hormone and Follicle-Stimulating Hormone Release

1991 ◽  
Vol 54 (5) ◽  
pp. 425-432 ◽  
Author(s):  
Darrell W. Brann ◽  
John K. McDonald ◽  
Carla D. Putnam ◽  
Virendra B. Mahesh
Keyword(s):  
Luteinizing Hormone ◽  
Neuropeptide Y ◽  
Follicle Stimulating Hormone ◽  
Gonadotropin Releasing Hormone ◽  
Hormone Release ◽  
Releasing Hormone ◽  
Immature Rats ◽  
Stimulating Hormone

scholarly journals Annual Change of Reproductive Hormones in Female Angora Goats

2017 ◽  
Vol 5 (4) ◽  
pp. 343
Author(s):  
Erkan Pehlivan ◽  
Hüseyin Polat ◽  
Gürsel Dellal
Keyword(s):  
Luteinizing Hormone ◽  
Repeated Measures ◽  
Follicle Stimulating Hormone ◽  
Reproductive Hormones ◽  
Gonadotropin Releasing Hormone ◽  
Blood Samples ◽  
Releasing Hormone ◽  
Angora Goats ◽  
Turkish State ◽  
Stimulating Hormone

In this research, annual changes of melatonin, gonadotropin-releasing hormone, follicle stimulating hormone, luteinizing hormone, estrogen, testosterone and progesterone were studied on 6 heads of 1.5 years old female Angora goat. To determine hormones concentrations, blood samples were taken from jugular vein of each goat in every month for a year. The blood samples were centrifuged at 4000xg for 5 min. and serum was stored at -20°C until analyses time. Hormones analyses in the serum were performed by enzyme immunoassay (EIA) method. Monthly climatic values and photoperiod were obtained from the Turkish State Meteorological Service and temperature-humidity index was calculated with climatic values. In the study, in order to determine any possible differences in the observed hormones concentrations with respect to months, repeated measures ANOVA analysis was performed. As a result of statistical analysis, there were no significant differences among the months for gonadotropin-releasing hormone, follicle stimulating hormone and testosterone concentration, while significant differences were found among the months for melatonin, luteinizing hormone and progesterone, and estrogen concentration in female Angora goats. According the results of this study, could be concluded that the releases of reproductive hormones examined in female Angora goats was seasonally dependent.

Luteinizing hormone and follicle-stimulating hormone responses to intransal gonadotropin-releasing hormone *

1986 ◽  
Vol 45 (6) ◽  
pp. 794-799 ◽  
Author(s):  
Jacob Rajfer ◽  
David J. Handelsman ◽  
Ronald S. Swerdloff ◽  
John H. Farrer ◽  
Suresh C. Sikka
Keyword(s):  
Luteinizing Hormone ◽  
Follicle Stimulating Hormone ◽  
Gonadotropin Releasing Hormone ◽  
Releasing Hormone ◽  
Hormone Responses ◽  
Stimulating Hormone

Responses of luteinizing hormone (LH) and follicle-stimulating hormone levels to exogenous gonadotropin-releasing hormone during the estrogen-induced LH surge in the ovariectomized rhesus monkey

1989 ◽  
Vol 67 (2) ◽  
pp. 135-139 ◽  
Author(s):  
Richard F. Weick ◽  
Vaclav Pitelka ◽  
David L. Thompson
Keyword(s):  
Luteinizing Hormone ◽  
Rhesus Monkey ◽  
Negative Feedback ◽  
Follicle Stimulating Hormone ◽  
Gonadotropin Releasing Hormone ◽  
Gonadotropin Secretion ◽  
Lh Surge ◽  
Releasing Hormone ◽  
Acute Response ◽  
Stimulating Hormone

Experiments were performed to study the responsiveness of the pituitary to gonadotropin-releasing hormone (GnRH) during the dynamic changes in gonadotropin secretion associated with the estrogen-induced luteinizing hormone (LH) surge in the ovariectomized (OVX) rhesus monkey. Silastic capsules filled with estradiol-17-β were implanted subcutaneously in ovariectomized rhesus monkeys, resulting in an initial lowering of circulating LH and follicle-stimulating hormone (FSH) concentrations followed by an LH–FSH surge. GnRH was injected intravenously just before estrogen implantation, during the negative feedback response and during the rising, the peak, and the declining phases of the LH surge. The LH and FSH responses during the negative feedback phase were as large as those before estrogen treatment (control responses). During the rising phase of the LH surge, the acute response to GnRH injection did not differ significantly from the control response, but the responses 60 and 120 min after injection were somewhat increased. During the declining phase of the LH surge, the pituitary was not responsive to exogenous GnRH, although LH probably continued to be secreted at this time since the LH surge decreased more slowly than predicted by the normal rate of disappearance of LH in the monkey. We conclude that an increased duration of response to GnRH may be an important part of the mechanism by which estrogen induces the LH surge, but we do not see evidence of increased sensitivity of the pituitary to GnRH as an acute releasing factor at that time.Key words: LH surge, GnRH, FSH, ovariectomized monkey.

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