Selective effect of KB-2796, a new calcium entry blocker, on cerebral circulation: a comparative study of the effects of calcium entry blockers on cerebral and peripheral arterial blood flows.
The effects of a new calcium entry blocker, KB-2796, on cerebral and peripheral circulation were compared with those of four other calcium entry blockers (flunarizine, cinnarizine, nicardipine, and diltiazem) and also papaverine in anesthetized dogs. KB-2796 increased the vertebral blood flow to the same extent as the other drugs. KB-2796 and the other drugs increased the coronary blood flow, although the effect of KB-2796 was obviously weaker than that of the other drugs. The dose of KB-2796 producing a 30% increase in coronary blood flow was about 20 times higher than that producing an equivalent increase in vertebral blood flow. KB-2796 and the other calcium entry blockers caused a moderate increase in both femoral and common carotid blood flow. The renal artery showed a biphasic response to all drugs, which consisted of an initial decrease and a subsequent increase in the flow. From these results, it is suggested that KB-2796 is a new type of calcium entry blocker that selectively affects the cerebral circulation. It is also concluded that calcium entry blockers have a different spectrum of vasodilatory action on coronary and cerebral vascular beds and that a selective coronary vasodilatory action is not a common feature among all calcium entry blockers.
Pharmaceuticals Research Center, Kanebo Ltd., Osaka, Japan.
T
T
Kanazawa
T
T
Morita
K
K
Harada
T
T
Iwamoto
H
H
Ohtaka
T
T
Sukamoto
K
K
Ito
S
S
Nurimoto
D000818:Animals; D001158:Arteries / Q000502:physiology; D001775:Blood Circulation / Q000187:drug effects*; D001794:Blood Pressure / Q000187:drug effects; D002121:Calcium Channel Blockers / Q000494:pharmacology*; D002560:Cerebrovascular Circulation / Q000187:drug effects*; D004285:Dogs; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D008297:Male; D010879:Piperazines / Q000494:pharmacology*; D012044:Regression Analysis
D002121:Calcium Channel Blockers; D010879:Piperazines; C052424:lomerizine