engleski

EXPRESSION OF WATER CHANNEL AQP1 IN RAT KIDNEYS IS STIMULATED BY ANDROGENS

AQP1 is assumed to be a constitutive water channel responsible for bulk water reabsorption in the mammalian kidneys. The protein is located in the cell membrane of proximal tubule and descending thin limb epithelium, where it exhibits non-glycosylated (~28 kDa) and glycosylated (40 kDa-50 kDa) forms. Possible factors influencing renal AQP1 expression in (patho)physiological conditions are largely unknown. Here we investigated the effects of sex hormones on renal AQP1 expression by immunofluorescence cytochemistry in tissue cryosection, by Western blotting in isolated membranes, and by real time RT-PCR in prepubertal and variously treated adult rats. In adult rats, the AQP1 protein expression was higher in males than in females ; sex differences were observed in both protein forms. The AQP1 mRNA expression matched the protein expression. Castration reduced and ovariectomy slightly increased, while the treatment of castrated animals with testosterone increased the abundance of AQP1 protein in the kidneys. The treatment with estradiol and progesterone had no effect. In prepubertal rats, the expression of both AQP1 protein and mRNA in the kidneys was similar in both sexes. Therefore, in the kidneys of adult rats, sex differences exist in the expression of AQP1 due to stimulating effect of androgens.

AQP1; kidneys; androgens

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