title: The effects of calcium antagonists and prostaglandin E1 on isolated canine coronary arterial tension.
abstract: The effects of calcium antagonists (nifedipine, nicardipine, diltiazem, and verapamil) and prostaglandin E1 (PGE1) on the tension of isolated canine coronary arterial strips were studied. In a solution containing 20 mEq/L of K+, 127 mEq/L of Na+, the tension was increased by 500-1,000 mg with 4 mEq/L of Ca2+. This increase in tension was suppressed by Ca-antagonists and PGE1 dose-dependently. Nifedipine 10(-5) M, nicardipine 3 x 10(-7) M, diltiazem 3 x 10(-6) M, and verapamil 3 x 10(-6) M completely suppressed the increased tension. The maximal suppression of the tension produced by PGE1 was about 40% at 10(-10) M. In 20 mEq/L K+ solution (0 mEq/L Ca2+, 37 degrees C), the reduction of the Na+ concentrations from 127 mEq/L to 12 mEq/L increased the tension by 50 to 100 mg. This increase in tension was not suppressed by Ca-antagonists or PGE1. In conclusion, this study demonstrated that Ca-antagonists and PGE1 suppressed an increase in the tension caused by Ca2+ but did not suppress an increase in the tension caused by Na+ reduction.
authors.affiliation: Department of Cardiovascular Surgery, Owari Hospital, Aichi, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Yoshida
authors.forename: J
authors.initials: J
authors.lastname: Iwase
authors.forename: F
authors.initials: F
authors.lastname: Murakami
authors.forename: A
authors.initials: A
authors.lastname: Usui
authors.forename: M
authors.initials: M
authors.lastname: Hibi
authors.forename: M
authors.initials: M
authors.lastname: Kawamura
mesh_terms: D000527:Alprostadil / Q000494:pharmacology*; D000818:Animals; D002118:Calcium / Q000502:physiology; D002121:Calcium Channel Blockers / Q000494:pharmacology*; D003331:Coronary Vessels / Q000187:drug effects* / Q000502:physiology; D003627:Data Interpretation, Statistical; D004110:Diltiazem / Q000494:pharmacology; D004285:Dogs; D066298:In Vitro Techniques; D009119:Muscle Contraction / Q000187:drug effects; D009131:Muscle, Smooth, Vascular / Q000187:drug effects; D009529:Nicardipine / Q000494:pharmacology; D009543:Nifedipine / Q000494:pharmacology; D011188:Potassium / Q000502:physiology; D012964:Sodium / Q000502:physiology; D012996:Solutions; D014700:Verapamil / Q000494:pharmacology
chemical_list: D002121:Calcium Channel Blockers; D012996:Solutions; D012964:Sodium; D014700:Verapamil; D009529:Nicardipine; D004110:Diltiazem; D000527:Alprostadil; D009543:Nifedipine; D011188:Potassium; D002118:Calcium