[Effect of manganese ions and verapamil on electrogenesis and contraction of ureter smooth muscle].

Fast and slow calcium channels of the electrically excitable membrane of the ureter smooth muscle cells had different sensitivity to manganese ions and verapamil. Manganese ions (10(-4) M) selectively blocked the fast potential--dependent Ca--channels, Ca ions being necessary for phasic contraction, whereas verapamil (10(-9)--10(-8)) specifically blocked the slow potential--dependent CA--channels.