The contraction induced by calcium ions in isolated guinea-pig vas deferens.
1. When isolated guinea-pig vas deferens was pretreated with 0.01% sodium edetate in an isotonic sucrose medium and then transferred to an edetate-free sucrose medium, the addition of CaCl2 (1.1 to 35.2 mmol/l) induced a contraction. 2. The contraction was greatest when the CaCl2 was added soon after pretreatment with edetate, and decreased with increasing time, almost disappearing after 1 h. 3. When KCl (1.4 to 22.4 mmol/l) was added in place of CaCl2, the contraction was lowest soon after pretreatment with edetate, and increased with time; after 1 h, the effect, was 80.7% of that observed in a preparation that had not been pretreaated with edetate.
D000818:Animals; D002118:Calcium / Q000494:pharmacology*; D002122:Calcium Chloride / Q000494:pharmacology; D004492:Edetic Acid / Q000494:pharmacology; D006168:Guinea Pigs; D066298:In Vitro Techniques; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects*; D009130:Muscle, Smooth / Q000187:drug effects*; D011189:Potassium Chloride / Q000494:pharmacology; D014649:Vas Deferens / Q000187:drug effects
D011189:Potassium Chloride; D004492:Edetic Acid; D002122:Calcium Chloride; D002118:Calcium