STUDIES ON THIAMINE PHOSPHATES : (V) PHARMACOLOGICAL ACTIONS OF S-BENZOYLTHIAMINE O-MONOPHOSPHATE

Abstract

Examinations were made on pharmacological actions of S-benzoylthiamine O-monophosphate (BTMP). Acute toxicity on mice was lower than that exerted by thiamine hydrochloride. BTMP depressed the myocardial activity of isolated hearts of frog and guinea pig though the action is weaker than that of thiamine hydrochloride or diphosphate. In urethan-anesthetized rabbit, a temporary and slight fall of blood pressure and a slight augmentation of the myocardial activity were observed with BTMP, while with thiamine hydrochloride or monophosphate, the temporary fall of the blood pressure was greater and a slight depression of the myocardial activity occurred. BTMP in concentration of 0.02-0.04% had almost no effect upon isolated intestine of rabbit, while thiamine hydrochloride or monophosphate in the same concentration caused a decrease in the peristalsis and fall of the tension. The above-mentioned experimental results demonstrate that pharmacological actions of BTMP are generally weaker than those of other thiamine derivatives.