Central estrogen-like effect of genistein on growth hormone secretion in the ewe

• Autorzy: Misztal T. , Wankowska M. , Gorski K. , Romanowicz K.
• Języki publikacji: EN

Abstrakty

EN

The present study tested a hypothesis, whether plant-derived genistein influences the secretion of growth hormone (GH) in ewes, acting directly within the central nervous system (CNS). Starting six weeks after ovariectomy, ewes were infused intracerebroventricularly with genistein (n=5) or 17β-estradiol (n=5), both in a total dose of 40 μg/400 μl/4 h, or with a vehicle (control, n=5). All infusions were performed from 10:00 am to 2:00 pm and blood samples were collected from 8:00 am to 8:00 pm at 10-min intervals. Five genistein- and three vehicle-infused ewes were slaughtered the following morning. The plasma GH concentration was assayed by the radioimmunoassay method, and immunoreactivity of GH in the adenohypophysis was determined by immunohistochemistry. In genistein-infused ewes, mean plasma GH concentration was significantly higher during the whole period of infusion than the concomitant concentration in vehicle-infused ewes. However, examining data within group, GH secretion rose gradually, reaching a significant value during the second phase of genistein infusion. In 17β-estradiol-infused animals, a significant increase in GH concentration was noted during the first two hours of the infusion, in comparison with vehicle-infused and also in comparison with genistein-infused ewes. Although a gradual increase in basic GH secretion continued in all treated groups during the afternoon and evening, mean plasma GH concentrations in genistein- and 17β-estradiol-infused ewes were still significantly higher than in the vehicle-infused. The percentage of GH-positive cells in the adenohypophysis and the density of immunoreactive material in these cells decreased significantly in genistein-infused ewes, compared to the control, indicating diminished hormone storage. In conclusion, genistein as 17β-estradiol, is an effective stimulator of GH secretion in ewes and may exert its effect at the level of the CNS.

• Wydawca: -
• Czasopismo: Acta Neurobiologiae Experimentalis
• Rocznik: 2007
• Tom: 67
• Numer: 4
• Opis fizyczny: p.411-419,fig.,ref.

Twórcy

autor

Misztal T.

• Department of Endocrinology, The Kielanowski Institute of Animal Physiology and Nutrition, Polish Academy of Sciences, Instytucka 3 St., 05-110 Jablonna n/Warsaw, Poland

autor

Wankowska M.

• Department of Endocrinology, The Kielanowski Institute of Animal Physiology and Nutrition, Polish Academy of Sciences, Instytucka 3 St., 05-110 Jablonna n/Warsaw, Poland

autor

Gorski K.

• Department of Endocrinology, The Kielanowski Institute of Animal Physiology and Nutrition, Polish Academy of Sciences, Instytucka 3 St., 05-110 Jablonna n/Warsaw, Poland

autor

Romanowicz K.

• Department of Endocrinology, The Kielanowski Institute of Animal Physiology and Nutrition, Polish Academy of Sciences, Instytucka 3 St., 05-110 Jablonna n/Warsaw, Poland

Uwagi

PL

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