Data/hora: 02/06/2024 17:44:19

Biblioteca(s): 	Embrapa Caprinos e Ovinos.	
Data corrente: 	17/05/1996	
Data da última atualização: 	17/05/1996	
Autoria: 	KILE, J. P.; NETT, T. M.	
Título: 	Differential secretion of folicle-stimulating hormone and luteinizing hormone from ovine pituitary cells following activation of protein kinase A, protein kinase C, or increased intracellular cacium.	
Ano de publicação: 	1994	
Fonte/Imprenta: 	Biology of Reproduction, v.50, n.1, p.49-54, 1994.	
Idioma: 	Inglês	
Conteúdo: 	A higher dose of GnRH is required to stimulate release of FSH than of LH, both in vivo and in vitro. Therefore, we tested the hypothesis that secretion of FSH may be mediated via a second messenger pathway different from the one that modulates secretion of LH. Pituitary cells from intact ewes were cultured in suspension in DMEM plus 10% wether serum. After 18 h, cell were washed and challenged for 2 h with agents capable of activating protein kinase A (dibutyryl cAMP), protein kinase C (phorbol 12-myristate 13-acetate; PMA), or increasing intracellular calcium (the calcium ionophore A23187). GnRH (0.01-10 DM) and PMA (0.2-20 nM) stimulated dose-dependent increases in secretion of LH. FSH secretion aIso was stimulated by GnRH and PMA; however, the percentage of total cellular FSH released was lower (p < 0.05) than the percentage of total cellular FSH released. Dibutyryl cAMP (10 mM) induced a modest release (p < 0.05) of both LH and FSH. A23187 (1-10 uM) stimulated secretion of LH in a dose-dependent manner but did not influence secretion of FSH; however, GnRH- and PMA-induced secretion of FSH required the presence of intracellular calcium. On the basis of the results of fuis study, we suggest that secretion of FSH is less than secretion of LH following direct activation of these second messenger systems. Furthermore, we suggest that in contrast to the situation for LH, increased intracellular calcium is not the primary stimulus for inducing secretion of FSH. 	
Palavras-Chave: 	Regulacao Metabolica.	
Thesagro: 	Hipófise; Ovino; Reprodução.	
Categoria do assunto: 	--	
Registro original: 	Embrapa Caprinos e Ovinos (CNPC)	
Exemplares: 	CNPC - (2717-1) - ADC - AP - -- -  -  - 1996.00000 - DIS