Estrogênio e progesterona modulam a expressão da proteína da Na+-K+-ATPase e do canal de sódio CNGA-1 em rins de ratas

• Autor(a) principal: Graceli, Jones Bernardes
• Data de Publicação: 2008
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Repositório Institucional da Universidade Federal do Espírito Santo (riUfes)
• Texto Completo: http://repositorio.ufes.br/handle/10/5159
• topic: Fisiologia; 612

Estrogen (E2) and progesterone (P4) are both steroids hormones and they are involved mainly in the control of female reproductive functions. Among other effects, E2 and P4 can modulate Na+ reabsorption along the nephron altering the body hydroelectrolyte balance. The female hormones can modulate corporal Na+ balance by alterations of ion channel and ion pumps expressions and activities. In this work, we studied the possible involvement of E2 and P4 in modulating the expression and function of Na+ -K+ -ATPase pump and sodium channel CNG-A1 in the kidney of female Wistar rats subjected to ovariectomy with or without near-physiological 17b-estradiol benzoate and progesterone treatment for 10 days. The CNGA-1 and Na-K-ATPase protein expression from cortex and medulla renal were analyzed by Western blot. The decreased renal cortex expression of CNGA-1 and Na+ -K+ -ATPase protein observed in OVX group was restored to control levels after treatment with doses of estradiol and progesterone. The Na+ ,K+ -ATPase activity in renal cortex decreased in 50% in OVX group and the replacement of estradiol or progesterone in OVX animals increased those parameters to control group values. The other hand, there was no significant variation of, CNGA-1 protein expression, Na+ ,K+ -ATPase protein expression and activity in the medulla renal tissue of animals subjected to the same treatment. The 17b-estradiol added to cell culture medium significantly increased rat renal culture proximal tubule cell CNG1-A protein expression and Na+ ,K+ -ATPase protein expression and activity of control levels. The indirect immunofluorescence microscopy of the female adult rat kidney labeled with anti-sodium channel-CNG1-A antibody revealed that CNG1- A was expressed in the basolateral membrane of proximal and distal connecting 16 tubules. The reactivity to this antibody was only seen in kidney cortex. No immunofluorescence was detected in kidney medulla. This results suggest that Na+ -K+ -ATPase and CNGA-1 would be included in the family of transporters stimulated by estrogen and progesterone in the kidney and it might have an important role in renal function and that Na+ -K+ - ATPase and CNGA-1 subunit would be function relation in reabsorption of sodium in the proximal tubules.