scholarly journals Regulation of gonadotropin subunit gene transcription

2004 ◽  
Vol 33 (3) ◽  
pp. 559-584 ◽  
Author(s):  
L L Burger ◽  
D J Haisenleder ◽  
A C Dalkin ◽  
J C Marshall
Keyword(s):  
Transcriptional Regulation ◽  
Luteinizing Hormone ◽  
Gene Transcription ◽  
Sexual Maturation ◽  
Follicle Stimulating Hormone ◽  
Reproductive Function ◽  
Gonadotropin Releasing Hormone ◽  
Subunit Gene ◽  
Pulsatile Release ◽  
Releasing Hormone

Reproductive function in mammals is regulated by the pituitary gonadotropins luteinizing hormone (LH) and follicle-stimulating hormone (FSH). LH and FSH are secreted by the gonadotrope cell and act on the gonad in a sequential and synergistic manner to initiate sexual maturation and maintain cyclic reproductive function. The synthesis and secretion of LH and FSH are regulated mainly by the pulsatile release of the hypothalamic decapeptide hormone gonadotropin-releasing hormone (GnRH). The control of differential LH and FSH synthesis and secretion is complex and involves the interplay between the gonads, hypothalamus and pituitary. In this review, the transcriptional regulation of the gonadotropin subunit genes is discussed in a physiologic setting, and we aimed to examine the mechanisms that drive those changes.

Pituitary and gonadal responsiveness is enhanced during GnRH-induced puberty

1988 ◽  
Vol 254 (5) ◽  
pp. E652-E657
Author(s):  
D. I. Spratt ◽  
W. F. Crowley
Keyword(s):  
Luteinizing Hormone ◽  
Sexual Maturation ◽  
Sexual Development ◽  
Follicle Stimulating Hormone ◽  
Gonadotropin Releasing Hormone ◽  
Releasing Hormone ◽  
Hormone Levels ◽  
Gnrh Secretion ◽  
Serum Luteinizing Hormone ◽  
Before And After

We hypothesized that the hypothalamic gonadotropin-releasing hormone (GnRH) signal that initiates sexual maturation is further amplified at both the pituitary and gonadal levels during puberty. To test this theory, six GnRH-deficient men were monitored during administration of exogenous GnRH at a physiological frequency for greater than or equal to 9 mo. GnRH doses were progressively increased until normal testosterone (T) concentrations and secondary sexual development were achieved. This "optimized" dose of GnRH was then sustained for at least 6 mo to allow maturation of the hypothalamic-pituitary-gonadal axis. The GnRH dose was then progressively decreased to a level that had been unable to stimulate normal T secretion before sexual maturation. Changes in pituitary responsiveness were analyzed in four of the six men by comparing gonadotropin responses to identical doses of GnRH before and after sexual maturation. Mean serum luteinizing hormone and follicle-stimulating hormone levels as well as luteinizing hormone pulse amplitudes were greater after the induction of sexual maturation than before despite identical doses of GnRH. Both pituitary and gonadal responsiveness was then analyzed in the remaining two subjects by choosing periods of evaluation where endogenous gonadotropin levels were matched before and after the period of sexual maturation. Serum T concentrations were greater after sexual maturation than before despite equivalent gonadotropin input to the testes and LH pulse amplitudes. Thus the testicular responsiveness to gonadotropins increased during sexual maturation. After initiation of puberty by GnRH secretion, amplification at both the pituitary and gonadal levels contributes to sexual maturation in the human.

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.

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