Stress-induced prolactin release in female, male and androgenized rats: influence of progesterone treatment
| Autor: | R. P. Deis, G. A. Jahn |
|---|---|
| Rok vydání: | 1986 |
| Předmět: |
Male
endocrine system medicine.medical_specialty Ovariectomy Endocrinology Diabetes and Metabolism media_common.quotation_subject Luteal phase Chorionic Gonadotropin Human chorionic gonadotropin Endocrinology Estrus Stress Physiological Dopamine Internal medicine medicine Animals Testosterone Ovulation Bromocriptine Progesterone media_common Chemistry Fenclonine Rats Inbred Strains Prolactin Rats Ovariectomized rat Female Serotonin hormones hormone substitutes and hormone antagonists medicine.drug |
| Zdroj: | Journal of Endocrinology. 110:423-428 |
| ISSN: | 1479-6805 0022-0795 |
| DOI: | 10.1677/joe.0.1100423 |
| Popis: | Ether stress applied at 10.00 h induced a 100% increase in serum prolactin in intact and ovariectomized androgenized rats. Ovariectomy significantly diminished the basal serum prolactin values observed in intact androgenized rats. Two doses of progesterone (5 mg) given to intact and ovariectomized androgenized rats 14 and 2 h before exposure to ether stress increased prolactin values in the control groups but completely prevented the effect of stress. Exposure to ether stress induced a 100% increase in serum prolactin values in androgenized rats with increased serum progesterone levels 4 days after the induction of ovulation and the luteal phase with human chorionic gonadotropin (hCG). A group of androgenized rats with induced maternal behaviour and which had been suckled for 6 days was given 100 i.u. hCG and suckled for another 6 days after the hCG-induced luteal phase had been established. The serum prolactin and progesterone values of these rats were significantly higher than those treated with hCG only and ether stress did not increase prolactin release. A greatly increased serum concentration of prolactin was obtained in pro-oestrous and oestrous virgin rats after exposure to ether stress. Serum prolactin was also increased by stress in male rats. Progesterone administration to these female and male rats prevented stress-induced prolactin release. To ascertain the part played by dopamine and serotonin in the effect of stress on prolactin release, groups of androgenized and oestrous female rats were treated with bromocriptine or p-chlorophenylalanine methylester hydrochloride (pCPA). The dopaminergic agonist bromocriptine markedly reduced prolactin levels in the unstressed androgenized rats, but did not prevent the prolactin increases induced by stress. Administration of pCPA had no effect on basal or stress-increased serum levels of prolactin. It is concluded that modifications of the ovarian steroid secretions, especially of progesterone, has profound effects on prolactin release in response to ether stress. The release of the hormone was not mediated by a dopaminergic or serotonergic regulatory pathway. J. Endocr. (1986) 110, 423–428 |
| Databáze: | OpenAIRE |
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