In agricultural settings, a single GH injection which elevates GH titers for 7 days [ ] at the time of either ovulation induction or insemination improves the pregnancy rate in cattle . Archives Internationales de Physiologiede Biochimie et de Biophysique. Endocr Res Commun.
Hormonal changes of puberty. Effects of exogenous somatotropin ST on gonadal function in ruminants and swine. Cell and Tissue Research. Precocious puberty and statural growth. The Leydig cells produce testosterone, which also is responsible for the secondary sexual characteristics of males.
Journal of Cellular Biochemistry. In females, the main sex hormones are estrogen and progesterone.
GH supplementation of the IVM medium may be part of the answer, since GH promotes the survival, activation, and growth of preantral follicles originating from goats , sheep [ ], and mice [ ]. GH similarly increases follicle size in undernourished cows [ ].
IGF-1, in turn, enhances the gonadotropin effect on the granulosa cell, and GH seems to act synergistically to facilitate ovarian maturation postmenarche. Namespaces Article Talk. Clin Endocrinol. The RWT method for the prediction of adult stature.
The somatometer hypothesis implicates nutritional and growth signals in the timing and tempo of puberty [ 40 ], and GH, IGF-I, and leptin may be the signals for adequate nutrition reviewed by [ 41 ]. Growth hormone cells as co-gonadotropes: partners in the regulation of the reproductive system. At this time, cells in the placenta will start producing a hormone called human placental lactogen HPL.
Developmental changes in the expression of the growth hormone receptor messenger ribonucleic acid and protein in the bovine ovary. The temporal increase in oocyte GH expression in some studies discussed above may partially reflect a local positive feedback loop between GH and ghrelin, since GH reciprocally stimulates ghrelin synthesis and secretion [ ], although it does not affect GHS-R1a mRNA or protein levels [ ].
Polymorphism of growth hormone gene and its association with seminal and sexual behavioral traits in crossbred cattle.