抄録
In order to clarify the role of Clock gene which is one of the main circadian-related genes, we recorded blood pressure (BP) and heart rate (HR) in the Clock mutant mice on Jcl:ICR background (Clockj) and wild-type mice (WT) using a telemetry system (TA11PA-C20; DSI). The recordings were conducted for 48 hours under 12h light–12h dark condition. BP in the Clockj was significantly higher than WT during the light period. HR in the Clockj was significantly lower than WT during the dark period. Daily mean of BP in the Clockj was significantly higher, and that of HR was significantly lower in comparison to WT. The acrophase of the diurnal rhythm of plasma corticosterone in Clockj was largely delayed in comparison to WT. We hypothesized that Clockj has some impairment of water balance controlled by adreno-cortical hormones. After aderenalectomy, the amplitude of BP and HR lost the significant difference between the Clockj and WT, although the acrophase did not change. It is possible that the altered function of adrenal gland, which is caused by the lack of normal Clock gene, may induce non-dipping circadian profile of BP and HR. [Jpn J Physiol 55 Suppl:S26 (2005)]
