Data/hora: 09/06/2024 05:42:40

Provedor de dados: 	56	
País: 	Brazil	
Título: 	Different stress modalities result in distinct steroid hormone responses by male rats	
Autores: 	Andersen,M.L.; Bignotto,M.; Machado,R.B.; Tufik,S.	
Data: 	2004-06-01	
Ano: 	2004	
Palavras-chave: 	Paradoxical sleep deprivation; Stress; Testosterone; Progesterone; Estrogen; Corticosterone.	
Resumo: 	Since both paradoxical sleep deprivation (PSD) and stress alter male reproductive function, the purpose of the present study was to examine the influence of PSD and other stressors (restraint, electrical footshock, cold and forced swimming, N = 10 per group) on steroid hormones in adult Wistar male rats. Rats were submitted to chronic stress for four days. The stressors (footshock, cold and forced swimming) were applied twice a day, for periods of 1 h at 9:00 and 16:00 h. Restrained animals were maintained in plastic cylinders for 22 h/day whereas PSD was continuous. Hormone determination was measured by chemiluminescent enzyme immunoassay (testosterone), competitive immunoassay (progesterone) and by radioimmunoassay (corticosterone, estradiol, estrone). The findings indicate that PSD (13.7 ng/dl), footshock (31.7 ng/dl) and cold (35.2 ng/dl) led to lower testosterone levels compared to the swimming (370.4 ng/dl) and control (371.4 ng/dl) groups. However, progesterone levels were elevated in the footshock (4.5 ng/ml) and PSD (5.4 ng/ml) groups compared to control (1.6 ng/ml), swimming (1.1 ng/ml), cold (2.3 ng/ml), and restrained (1.2 ng/ml) animals. Estrone and estradiol levels were reduced in the PSD, footshock and restraint groups compared to the control, swimming and cold groups. A significant increase in corticosterone levels was found only in the PSD (299.8 ng/ml) and footshock (169.6 ng/ml) groups. These changes may be thought to be the full steroidal response to stress of significant intensity. Thus, the data suggest that different stress modalities result in distinct steroid hormone responses, with PSD and footshock being the most similar.	
Tipo: 	Info:eu-repo/semantics/article	
Idioma: 	Inglês	
Identificador: 	http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2004000600003	
Editor: 	Associação Brasileira de Divulgação Científica	
Relação: 	10.1590/S0100-879X2004000600003	
Formato: 	text/html	
Fonte: 	Brazilian Journal of Medical and Biological Research  v.37 n.6 2004	
Fonte: 	info:eu-repo/semantics/openAccess