Abstract
The pharmacological actions of T-1220, which is a new type of semisynthetic penicillin and is effective against severe infections by gram-negative bacilli, were investigated.
Summary of pharmacological actions and minimal effective doses (MED) were as follows : fall. of blood pressure of the rabbit (200 mg/kg), inhibition of isolated frog heart (10-3 g/ml), dilation of isolated rabbit ear vessels (5×10-2 g/ml), inhibition of isolated guinea pig intestine (10-3 g/ml), and no effect on respiration of the rabbit (upto 500 mg/kg), on rabbit ECG (upto 100 mg/kg), on isolated guinea pig heart (upto 5×10-3 g/ml), on permeability of rabbit skin vessels (upto 1, 000 μg), on isolated rabbit intestine (upto 2×10-3 g/ml), on isolated guinea pig trachea (upto 5×10-3 g/ml), on isolated rat uterus (upto 2×10-3 g/ml) and on isolated uterus of the pregnant rat (5 ×10-3 g/ml).
MED of T-1220 were much larger than minimal inhibitory concentrations and maximal blood levels in clinical uses.
MED of T-1220 were much smaller than those of ampicillin and similar to those of carbenicillin.
The pharmacological actions and MED of P-32 were similar to those of T-1220, except stimulating effect on isolated intestine.
The increase in body weight, volume of urine, urinary excretion of potassium and urinary findings in the rat applied T-1220 in doses from 100 to 500 mg/kg subcutaneously once a day for 7 days were similar to normal values and those of control group. Decreased urinary excretion of sodium was observed in proportion to the doses applied.
