The difference between nicardipine and its enantiomers on inhibiting vasoconstriction of isolated rabbit thoracic artery.
The present study was designed to study the difference effects between nicardipine and its two enantiomers on thoracic artery of rabbit. A high-performance liquid chromatographic method was used to prepare the two enantiomers of nicardipine. The thoracic artery of rabbit was removed. The vessels were cut into 3 mm in width and 15 mm in length spiral strips and immersed into tissue baths. The concentration-response curves of nicardipine and its enantiomers were obtained by cumulative administration of the vasoconstrictors. Nicardipine and the enantiomers could shift the dose-response curves of NE, KCl or CaCl2 to right in a nonparallel manner and decrease the maximum effective in a concentration-depended manner, respectively. The pD2' value of R-(-)-nicardipine showed significantly effective than that of nicardipine and S-(+)-nicardipine (P<0.01). There was not obviouse difference between the pD2' value of nicardipine and S-(+)-nicardipine (P>0.05). The results demonstrate that the stereoselective interaction between R-(-)-nicardipine and L-calcium channel receptor is more stronger than that of S-(+)-nicardipine.
Wang
Sicen
S
College of Pharmacy, Xi'an Jiaotong University, Xi'an 710061, China.
He
Langchong
L
Yun
Bofeng
B
D000818:Animals; D000959:Antihypertensive Agents / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D002121:Calcium Channel Blockers / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D002851:Chromatography, High Pressure Liquid; D003864:Depression, Chemical; D005260:Female; D066298:In Vitro Techniques; D008297:Male; D009529:Nicardipine / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D011817:Rabbits; D013237:Stereoisomerism; D013329:Structure-Activity Relationship; D013895:Thoracic Arteries / Q000187:drug effects* / Q000502:physiology; D014661:Vasoconstriction / Q000187:drug effects*
D000959:Antihypertensive Agents; D002121:Calcium Channel Blockers; D009529:Nicardipine