Effects of pindolol, sotalol and the optical isomers of propranolol on muscle action potentials and depolarization-secretion coupling in the rat.
Muscle action potentials and miniature end-plate potential frequency were studied in different concentrations of pindolol, d- and l-propranolol and sotalol using intracellular microelectrode recording from rat phrenic nerve-diaphragm preparations. d-and l-propranolol at concentrations of 10 to 40 mg/l and pindolol at 20 to 100 mg/l slowed down the rate of rise, prolonged rise and half-decay times and reduced the overshoot of the muscle action potentials. Sotalol had similar effects but only at higher concentrations (100 to 200 mg/l). The drugs had no effect on the increase in the miniature end-plate potential frequence obtained with depolarization by increased extracellular potassium concentration.
D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D009045:Motor Endplate / Q000187:drug effects*; D009132:Muscles / Q000187:drug effects*; D009469:Neuromuscular Junction / Q000187:drug effects*; D010869:Pindolol / Q000494:pharmacology*; D011433:Propranolol / Q000494:pharmacology*; D051381:Rats; D013015:Sotalol / Q000494:pharmacology*
D011433:Propranolol; D013015:Sotalol; D010869:Pindolol