SHR에 alpha-Methyldopa를 Timolol 또는 Labetalol과 병용투여시 혈압강하효과에 관한 연구

Antihypertensive Effect of alpah-Methyldopa Administered Concurrent with Timolol or Labetalol in SHR.

The antihypertensive effect of alpha-methyldopa administered concurrently with timolol or labetalol were studied with spontaneously hypertensive rats (SHR). Every drugs were administered orally once a day after prechecking the systolic blood pressure and heart rate of SHR. The blood pressure and heart rate of SHR were significantly decreased in groups of combination while those of non-combination groups were fallen slightly. Compared with control group, the significant changes of blood pressure was observed in group of alpha-methyldopa with timolol (100mg + 2mg/kg)and alpha-methyldopa with labetalol (100mg + 12.5mg/kg). The group of alpha-methyldopa with timolo 1 (100mg + 1.Omg/kg) reduced blood Pressure in similar degree as manifested in group of alpha-methyldopa with labetalol (100mg + 50mg/kg.). In the group that alpha-methyldopa was administered concurrently with timolol, the maximum antihypertensive effect and heart rate decreasing effect were appeared after 3 hr and 1 hr of administration respectively and those effects in group of alpha-methyldopa with labotalol were appeared after 6 hr of administration. The acute oral toxicity test was performed using albino mice with alpha-methyldopa alone, alpha-methyldopa with timolol (100:1) and alpha-methyldopa with labetalol (4:1), and was found that the LD50 of alpha-methyldopa alone was 1104mg/kg, alpha-methyldopa with timolol (100:1) was 1115mg/kg and alpha-methyldopa with labetalol (4:1) was 354mg/kg.