1,721,037 research outputs found
Oppioidi ed attivazione puberale: regolazione della funzione surrenalica e riproduttiva e della secrezione gonadotropinica.
No full textThe transition from pubertal development to postmenopause discloses a gonadotropin-releasing hormone-independent mechanism regulating follicle-stimulating hormone release
No full textThe reproductive function is tightly dependent on gonadotropin secretion and the optimal activity of the hypothalamus-pituitary axis. This study discusses evidence that supports the possible existence of a GnRH-independent modulator of FSH secretion in humans. Stich a hypothesis has been consistently reported in several experimental animals. To test the hypothesis specific times during the physiological development and activity of the hypothalamus-pituitary axis have been evaluated under the use of drugs acting directly on hypothalamic GnRH-secreting neurons, such as GnRH agonists. The possible presence also in humans of such an independent FSH stimulator might be important for the understanding of anovulation and infertility
Insulin resistance, PCOS and obesity: from metformin to integrative treatments that can improve insulin sensitivity
No full textModulatory effects of a synthetic steroid (tibolone) and estradiol on spontaneous and GH-RH-induced GH secretion in postmenopausal women.
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Plasma gonadotropin releasing hormone and corticotropin releasing hormone levels in pathological pregnancies
No full textProgesterone and progestins modulate beta-endorphin concentrations in the hypothalamus and in the pituitary of castrated female rats.
No full textHypothalamic and pituitary beta-endorphin (B-EP) concentrations are modified by ovariectomy and estrogen treatments, supporting a direct interaction between this peptidergic system and gonadal steroids. Because the use of progestins is becoming even more diffuse in clinical practice, we evaluated the effect of progesterone and of the synthetic progestins medroxyprogesterone acetate (MPA), norethisterone acetate (NET) and desogestrel on the concentration of B-EP in the medial-basal hypothalamus and the anterior and neurointermediate pituitary lobes in ovariectomized rats (OVX), treated or untreated with estradiol benzoate (EB). B-EP concentrations were significantly increased by desogestrel in the anterior lobe and by progesterone, desogestrel and medroxyprogesterone acetate in the neurointermediate lobe. Progesterone and progestins significantly reduced B-EP increase induced by estradiol benzoate in the anterior lobe. Estradiol benzoate treatment did not modify the effect of progesterone and desogestrel on B-EP in the neuro-intermediate pituitary lobe. Norethisterone acetate and progesterone increased B-EP concentrations in the medial-basal hypothalamus, while the other steroids were inactive. In contrast, in the hypothalamus all progestins attenuated the increase of B-EP induced by estradiol benzoate (p less than 0.01). These data indicate that progesterone and progestins modulate the hypothalamic and pituitary B-EP concentrations in concert with estrogens. The capacity of progestins to modify the hypothalamic contents of B-EP may represent one of the mechanisms of action of these steroids in influencing brain function
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