Use of isoptin for counteracting the effect of methol on cardiac activity in experimental animals

The purpose of the present study is to use isoptin in order to lower intracellular Ca2+ concentration for counteracting the effect of methol on cardiac activity in acute intoxication of the experimental animals. Adult male Wistar rats were used - 8 animals/lot anaesthesized with urethan. ECG activity was recorded every 15 minutes, for 360 minutes. Administration (oral) of methol in a dose of 310 mg/kg/bw. (DL100) produced sinusal bradycardia, which became more marked later on. Isoptin administration in a dose of 5 mg/kg/bw. in rats with 310 mg/kg/bw. methol decreased the heart rate, the lowest value occurring 120 minutes after administration, followed by a slow increase until the end of the recording. When isoptin was given in a dose of 2.5 mg/kg/bw. to rats with 310 mg/kg/bw. methol, the decrease of the heart rate was much slower than before, for a period of 255 minutes, followed by a slight increase until the end of the recording. Isoptin counteracts the bradycardia - producing effect of methol in rats during the study time (6 hours), and the effect after this period of time requires further investigations.