EFFECT OF DIETARY NITRATE ON ENDOGENOUS NITROSATION OF PIPERAZINE IN HUMANS

The effect of dietary nitrate on endogenous nitrosation of a therapeutic dose of piperazine has been described in five human volunteers who acted as their own controls, The urinary excretion of endogenously formed N-nitrosomonopiperazine (MNPz) ranged between 9.2 and 80.1-mu-g/24 h on a normal uncontrolled diet which increased from 25.7 to 163. 7-mu-g/24 h when the diet was supplemented with 250 mg nitrate. The corresponding urinary nitrate was 63.0-122.7 mg/24 h and 119.2-322.0 mg/24 h, respectively. The dinitroso derivative of piperazine was detected only in trace amounts and no detectable increase in its excretion was observed during high nitrate exposure. The unchanged piperazine (range 294-784 mg/24 h) in urine showed a decrease under high nitrate regimen (range 185-399 mg/24 h).