Effects of nicardipine on collar-induced intimal thickening and vascular reactivity in the rabbit.
The effects of nicardipine treatment on collar-induced intimal thickening and on accompanying reactivity changes in rabbit carotid artery have been investigated. Treatment for three weeks with subcutaneous nicardipine (20 mgkg(-1) per day) significantly inhibited the intimal thickening caused by perivascular application of a silicone rubber collar. Potassium chloride (KCl), phenylephrine and 5-hydroxytryptamine (5-HT) induced concentration-dependent contractions in both sham-operated and collared arteries. Collar-induced attenuation of maximum KCl-, phenylephrine- and 5-HT-induced contraction was not affected by nicardipine. Collaring caused the means of pD2 values (the negative logarithm of EC50 values, 50% effective concentration) of 5-HT and phenylephrine to increase and decrease, respectively. Nicardipine did not affect the altered sensitivity to these agonists. Neither collar implantation nor nicardipine treatment altered the pD2 values for acetylcholine- and nitroglycerine-induced relaxations. These results demonstrate that nicardipine inhibits collar-induced intimal thickening in rabbit carotid artery without affecting the accompanying changes in vascular reactivity, indicating a possible lack of association between the development of intimal thickening and altered reactivity.
Kerry
Z
Z
Department of Pharmacology, Faculty of Pharmacy, Ege University, Izmir, Turkey.
Yasa
M
M
Akpinar
R
R
Sevin
G
G
Yetik
G
G
Tosun
M
M
Ozdemir
N
N
Erhan
Y
Y
Ustünes
L
L
Ozer
A
A
D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D001835:Body Weight / Q000187:drug effects; D002121:Calcium Channel Blockers / Q000494:pharmacology*; D002339:Carotid Arteries / Q000187:drug effects* / Q000503:physiopathology; D002340:Carotid Artery Diseases / Q000209:etiology / Q000401:mortality / Q000517:prevention & control*; D004305:Dose-Response Relationship, Drug; D005260:Female; D008297:Male; D009529:Nicardipine / Q000494:pharmacology*; D005996:Nitroglycerin / Q000494:pharmacology; D010656:Phenylephrine / Q000494:pharmacology; D011817:Rabbits; D012701:Serotonin / Q000494:pharmacology; D015996:Survival Rate; D017539:Tunica Intima / Q000187:drug effects* / Q000473:pathology; D014661:Vasoconstriction / Q000187:drug effects; D014662:Vasoconstrictor Agents / Q000494:pharmacology; D014664:Vasodilation / Q000187:drug effects; D014665:Vasodilator Agents / Q000494:pharmacology
D002121:Calcium Channel Blockers; D014662:Vasoconstrictor Agents; D014665:Vasodilator Agents; D010656:Phenylephrine; D012701:Serotonin; D009529:Nicardipine; D005996:Nitroglycerin; D000109:Acetylcholine