EFFECT OF ACUTE AND REPEATED EXPOSURE TO LOW-DOSES OF HYDRAZINE ON HEPATIC-MICROSOMAL ENZYMES AND BIOCHEMICAL PARAMETERS IN-VIVO

A single dose of hydrazine (3 mg.kg(-1) i.p.) caused hepatic accumulat ion of triglycerides and depletion of ATP in rats after 9 h. Repeated exposure of rats to hydrazine (congruent to 2.5 mg.kg(-1) per day) for 10 days resulted in depletion of hepatic reduced glutathione (GSH) an d triglycerides. Repeated exposure to hydrazine also caused a signific ant (time dependent) induction of p-nitrophenol hydroxylase (NPH) acti vity together with changes in other hepatic microsomal enzymes. These included 7-pentoxyresorufin O-deethylase (PROD) and 7-ethoxyresorufin O-de ethylase (EROD) activity, total cytochrome P450, cytochrome b(5) and cytochrome P450 reductase activity. Repeated exposure to lower lev els of hydrazine (congruent to 0.250 mg.kg(-1) per day) caused no sign ificant hepatic biochemical or microsomal changes after 5 or 10 days e xcept for an increase in NPH activity (17%) and liver ATP (15%) after 5 days.