Effects of thioproline on experimental arrhythmia

Intravenous injections of thioproline (T) 5-10 mg/kg shortened the duration of arrhythmia elicited by iv epinephine 50 μg/kg in unanesthetized rabbits, reduced the mortality of mice given iv CaCl2 130 mg/kg, increased the dose of ouabain required for ventricular fibrillation in anesthetized guinea pigs, delayed the onset of arrhythmia evoked by iv aconitine 20 μg/kg in anesthetized rats, reduced the morbidity of dogs given 10% ACh 0.05 ml on the atrium, and antagonized or prevented the positive inotropic and chronotropic effects of isoproterenol. These results suggested that T exerted anti-arrhythmic actions Via sympathetic nervous system.The iv LD50 of T was 165 mg/kg in mice.