Changes in blood pressure and heart rate following dietary-induced thiamine deficiency in muricide rats.

The purpose of this study was to further investigate the effects of thiamine deficiency on blood pressure and heart rate in connection with muricide in rats. The rats, maintained on a thiamine-deficient diet, showed mouse-killing response (muricide). The incidence of muricide was 72% on day 30. In this period, marked decreases in body weight, heart rate and blood pressure were observed in thiamine-deficient rats. The changes of body weight and blood pressure were statistically different from pair-fed and control groups. In thiamine-deficient group, blood pressure of thiamine-deficient killer rats was lower than that of thiamine-deficient non-killer rats. It is noteworthy that recovery of bradycardia and hypotension was observed in thiamine-deficient rats after providing them with enough thiamine, but muricide was not recovered. Thus, it is unlikely that there is a direct correlation between muricide and the disturbance of cardiovascular system in thiamine-deficient killer rats. The present findings showed that muricide induced by thiamine deficiency has different physiological bases from the other types of muricide, i.e., olfactory bulb-lesioned muricide.