Effects of a dual L/N-type Ca(2+) channel blocker cilnidipine on neurally mediated chronotropic response in anesthetized dogs.
We investigated the effects of an L-type and N-type Ca(2+) channel blocker, cilnidipine, on neurally mediated chronotropic responses to clarify the anti-autonomic profile of cilnidipine in anesthetized dogs. Pretreatment with cilnidipine (0.3, 1.0 and 3.0 microg/kg, i.v.), which decreased mean blood pressure by 5 to 31 mm Hg, inhibited the changes in heart rate and plasma norepinephrine concentration induced by bilateral carotid artery occlusion, whereas it had no effect on vagal nerve stimulation-induced bradycardia. These results suggest that antihypertensive and antisympathetic doses of cilnidipine fail to influence chronotropic responses mediated by parasympathetic nerve activation in the in vivo canine heart.
Konda
T
T
Pharmaceutical Research Laboratories, Ajinomoto Co., Inc., 1-1 Suzuki-cho, Kawasaki, Kawasaki 210-8681, Japan.
Takahara
A
A
Maeda
K
K
Dohmoto
H
H
Yoshimoto
R
R
D000768:Anesthesia, General; D000818:Animals; D000959:Antihypertensive Agents / Q000494:pharmacology / Q000627:therapeutic use; D001794:Blood Pressure / Q000187:drug effects; D001919:Bradycardia / Q000097:blood / Q000188:drug therapy; D002121:Calcium Channel Blockers / Q000494:pharmacology* / Q000627:therapeutic use; D020746:Calcium Channels, L-Type / Q000378:metabolism*; D020864:Calcium Channels, N-Type / Q000378:metabolism*; D002339:Carotid Arteries / Q000503:physiopathology; D003327:Coronary Disease / Q000503:physiopathology; D004095:Dihydropyridines / Q000494:pharmacology* / Q000627:therapeutic use; D004285:Dogs; D004558:Electric Stimulation; D006321:Heart / Q000187:drug effects*; D006339:Heart Rate / Q000187:drug effects*; D008297:Male; D009638:Norepinephrine / Q000097:blood; D014630:Vagus Nerve / Q000502:physiology*
D000959:Antihypertensive Agents; D002121:Calcium Channel Blockers; D020746:Calcium Channels, L-Type; D020864:Calcium Channels, N-Type; D004095:Dihydropyridines; C065927:cilnidipine; D009638:Norepinephrine