Data/hora: 13/06/2024 07:05:02

Biblioteca(s): 	Embrapa Caprinos e Ovinos.	
Data corrente: 	06/11/2002	
Data da última atualização: 	06/11/2002	
Autoria: 	UNNO, N.; WU, W. X.; WONG, C. H.; BENNETT, P. R.; SHINOZUKA, N.; NATHANIELSZ, P. W.	
Título: 	Prostaglandin regulation of fetal plasma adrenocorticotropin and cortisol concentrations in late-gestation sheep.	
Ano de publicação: 	1998	
Fonte/Imprenta: 	Biology of Reproduction, v. 58, n. 2, p. 514-519, 1998.	
Idioma: 	Inglês	
Conteúdo: 	It is widely recognized that prostaglandins (PCs) are involved I in regulation of the hypothalamo-pituitary-adrenal axis and that  the activation of the fetal hypothalamo-pituitary-adrenal axis plays a central role in the process of labor in sheep. However,  effects of inhibition of PC synthesis on lhe maternal and fetal  hypothalamo-pituitary-adrenal axis during parturition have not been characterized. We examined lhe effect of inhibiting PC synthesis on lhe maternal and fetal hypothalamo-pituitary-ad- renal axes during spontaneous term labor by using nimesulide, a PCH synthase (PCHS) inhibitor. Under halothane anesthesia, eight pregnant ewes were instrumented with vascular catheters and myometrial electromyogram (EMC) electrodes at 127 +- 3 (mean +- SEM) days gestation (dGA). After onset of labor as evaluated by EMC, nimesulide was infused to four ewes i.v. (30- mg bolus, followed by 6-h infusion at 30 mg/h). Vehicle was infused to lhe remaining four ewes (controls, CONT). Maternal blood and fetal blood were sampled at 1-h intervals before and during infusion to determine plasma PCE2, ACTH, and cortisol concentrations. Spontaneous labor occurred at 148 +- 0 dGA in nimesulide-treated ewes and at 144 +- 1 dGA in CONT ewes. We infused nimesulide from 9 +- 2 h and vehicle from 8 +- 2 h after lhe onset of labor. Maternal and fetal blood gases and pH remained unchanged in ali animais. No significant changes were observed in any plasma hormone concentrations measured in CONT ewes and fetuses before and during vehicle infusion. In nimesulide-treated ewes, maternal plasma PCE2 and ACTH concentrations remained unchanged, while maternal plasma cortisol decreased significantly, recovering to baseline by 3 h. In fetuses of nimesulide-treated ewes, plasma PGE2 and ACTH levels showed significant sustained decreases after nimesulide infusion. Fetal plasma cortisol decreased significantly and returned to baseline by 5 h. These results suggest that 1) PC synthesis inhibition by nimesulide has differential effects on lhe ovine maternal and fetal hypothalamo-pituitary-adrenal axes during spontaneous labor, and 2) PC production plays a physiologic role in regulation of lhe ovine fetal hypothalamo-pituitary-adrenal axis. 

Palavras-Chave: 	Endrocinologia.	
Thesagro: 	Hormônio; Ovino; Prenhez; Prostaglandina; Reprodução Animal.	
Thesaurus Nal: 	cortisol.	
Categoria do assunto: 	--	
Registro original: 	Embrapa Caprinos e Ovinos (CNPC)	
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