Reduced α‐adrenoceptor responsiveness and enhanced baroreflex sensitivity in Cry‐deficient mice lacking a biological clock

摘要: To reveal the role of clock genes in generating circadian rhythm baroreflexes, we continuously measured mean arterial pressure and baroreflex sensitivity free-moving normal wild-type mice, Cry-deficient mice which lack a rhythm, constant darkness for 24 h. In was higher at night than during day, accompanied by significantly enhanced −13.6 ± 0.8 compared with −9.7 0.7 beats min−1 mmHg−1 day (P < 0.001). On other hand, diurnal changes disappeared remarkably 0.001): −21.9 1.6 −23.1 2.1 day. Moreover, response to 10 μg kg−1 phenylephrine, an α1-adrenoceptor agonist, severely suppressed regardless time, while that 10.1 1.9 mmHg night, lower 22.0 3.5 0.01). These results suggest CRY are involved sensitivity, partially regulating α1-adrenoceptor-mediated vasoconstriction peripheral vessels.