Effects of long-term treatment with calcium antagonists on periarterial nerve function in the mesenteric artery of spontaneously hypertensive rats.
The effect of long-term treatment with dihydropyridine calcium antagonists (amlodipine, pranidipine, nicardipine) on the periarterial nerve function was investigated in the perfused mesenteric vascular bed isolated from spontaneously hypertensive rat (SHR). Male 8-week-old SHR received amlodipine (0.01% and 0.02%) and nicardipine (0.1%) in drinking water and pranidipine (0.0035% and 0.035%) in rat chow for 7 weeks. Mean blood pressure in SHR was significantly lowered by long-term treatment with each calcium antagonist. In mesenteric vascular preparations treated with each calcium antagonist, vasoconstriction induced by periarterial nerve stimulation (PNS; 4, 8 and 12 Hz) was significantly smaller than that in non-treated SHR. The PNS (8 Hz)-evoked norepinephrine (NE) overflow in the perfusate was significantly decreased by amlodipine and pranidipine treatment, whereas nicardipine-treatment significantly enhanced the overflow of NE. In preparations with active tone produced by methoxamine and guanethidine, the PNS-induced vasodilation mediated by calcitonin gene-related peptide (CGRP)-containing (CGRPergic) vasodilator nerves was not affected by these drugs. These results suggest that long-term treatment of SHR with long-acting drugs, amlodipine and pranidipine, reduces sympathetic adrenergic nerve function but calcium antagonists have no effect on CGRPergic nerve function.
Nakatsuma
A
A
Department of Clinical Pharmaceutical Science, Graduate School of Natural Science and Technology, Okayama University, Japan.
Kawasaki
H
H
Kurosaki
Y
Y
Futagami
K
K
Araki
H
H
Gomita
Y
Y
D017311:Amlodipine / Q000494:pharmacology*; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D002121:Calcium Channel Blockers / Q000494:pharmacology*; D004095:Dihydropyridines / Q000494:pharmacology; D004347:Drug Interactions; D006973:Hypertension / Q000188:drug therapy*; D008297:Male; D008638:Mesenteric Arteries / Q000187:drug effects* / Q000502:physiology; D009420:Nervous System / Q000187:drug effects*; D009529:Nicardipine / Q000494:pharmacology; D009638:Norepinephrine / Q000494:pharmacology; D051381:Rats; D011918:Rats, Inbred SHR; D014662:Vasoconstrictor Agents / Q000494:pharmacology; D014665:Vasodilator Agents / Q000494:pharmacology
D002121:Calcium Channel Blockers; D004095:Dihydropyridines; D014662:Vasoconstrictor Agents; D014665:Vasodilator Agents; D017311:Amlodipine; C048161:pranidipine; D009529:Nicardipine; D009638:Norepinephrine