Mechanisms of relaxation by urocortin in renal arteries from male and female rats
Tóm tắt
Urocortin is a peptide recently identified, which is structurally related to the corticotropin‐releasing factor (CRF). To analyze the mechanisms that could be involved in its effect on renal arteries from male and female rats, the response to urocortin was studied in isolated segments, 2 mm long, of renal arteries from male and female rats. In renal artery segments precontracted with endothelin‐1 (1 n This relaxation was reduced by the antagonists of urocortin receptors astressin (1 In renal arteries from female rats, the relaxation to urocortin was reduced by the inhibitor of adenyl cyclase SQ22536 (300 In renal arteries from male rats, the relaxation to urocortin was increased by ryanodine, and was not modified by SQ22536 or 8‐bromo‐cADPR. These results suggest that the mechanisms involved in the relaxation to urocortin in renal arteries differ between female and male rats. In female rats, this relaxation may be mediated by the production of cyclic AMP (cAMP), synthesis of cADPR and release of sarcoplasmic Ca2+, whereas in male rats it is not mediated by cAMP.
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Tài liệu tham khảo
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