Diurnal amplitudes of arterial pressure and heart rate are dampened in Clock mutant mice and adrenalectomized mice.
Arterial pressure (AP), heart rate (HR), and cardiovascular diseases, including ischemic heart attack and cerebrovascular accident, show diurnal variation. Evidence that circadian-related genes contribute to cardiovascular control has been accumulated. In this study, we measured the AP and HR of Clock mutant mice on the Jcl/ICR background to determine the role of the Clock gene in cardiovascular function. Mice with mutated Clock genes had a dampened diurnal rhythm of AP and HR, compared with wild-type control mice, and this difference disappeared after adrenalectomy. The diurnal acrophase in both mean arterial pressure and HR was delayed significantly in Clock mutant mice, compared with wild-type mice, and this difference remained after adrenalectomy. Clock mutant mice had a lower concentration of plasma aldosterone, compared with wild-type mice. Our data suggest that the adrenal gland is involved in the diurnal amplitude, but not the acrophase, of AP and HR, and that the function of the Clock gene may be related to the nondipping type of AP elevation.
Sei
Hiroyoshi
H
Department of Integrative Physiology, Institute of Health Biosciences, The University of Tokushima Graduate School, Tokushima, Japan. sei@basic.med.tokushima-u.ac.jp
Oishi
Katsutaka
K
Chikahisa
Sachiko
S
Kitaoka
Kazuyoshi
K
Takeda
Eiji
E
Ishida
Norio
N
D000315:Adrenalectomy / Q000379:methods*; D000818:Animals; D001794:Blood Pressure / Q000502:physiology*; D056926:CLOCK Proteins; D002940:Circadian Rhythm / Q000502:physiology*; D005260:Female; D005838:Genotype; D006339:Heart Rate / Q000502:physiology*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D008813:Mice, Inbred ICR; D008817:Mice, Mutant Strains; D009154:Mutation; D015534:Trans-Activators / Q000235:genetics / Q000502:physiology*
D015534:Trans-Activators; D056926:CLOCK Proteins; C538944:Clock protein, mouse