Effects of amlodipine on circadian rhythms in blood pressure, heart rate, and motility: a telemetric study in rats.
In male Wistar rats [light(L): 07:00-19:00 h, dark(D): 19:00-07:00 h], the effects of the calcium channel blocker amlodipine (1, 3, 10 mg/kg i.p.) on blood pressure, heart rate, and motor activity were studied by telemetric monitoring. Amlodipine was injected either at 07:00 h or at 19:00 h. Systolic and diastolic blood pressure were dose-dependently decreased with more pronounced effects in the dark span, ED50 values in D were about seven times lower than in L. In contrast, the dose-dependent increase in heart rate was more pronounced in L than in D. No significant effects of amlodipine were found on motor activity. The study gives evidence for a circadian phase-dependency in the cardiovascular effects amlodipine in rats.
Mattes
A
A
Zentrum der Pharmakologie, J. W. Goethe Universität, Frankfurt, Germany.
Lemmer
B
B
D017311:Amlodipine; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects / Q000502:physiology; D002121:Calcium Channel Blockers / Q000008:administration & dosage / Q000494:pharmacology; D002940:Circadian Rhythm / Q000187:drug effects* / Q000502:physiology; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D006339:Heart Rate / Q000187:drug effects / Q000502:physiology; D008297:Male; D009043:Motor Activity / Q000187:drug effects / Q000502:physiology; D009543:Nifedipine / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains
D002121:Calcium Channel Blockers; D017311:Amlodipine; D009543:Nifedipine