INTERACTIONS BETWEEN HEPATIC ASCORBIC-ACID, CYTOCHROME-P-450 AND LIPIDS IN FEMALE GUINEA-PIGS WITH DIFFERENT ASCORBIC-ACID INTAKE

Changes in serum and liver lipids, hepatic ascorbic acid (AA) and cyto chrome P-450 were investigated in female guinea pigs divided into thre e groups with different AA intake in drinking water (10, 100 and 1000 mg AA per liter) for 10 weeks. Serum and liver total cholesterol signi ficantly decreased in guinea pigs receiving 100 and 1000 mg AA per lit er of drinking water when compared with guinea pigs with suboptimal AA intake (10 mg/l). Similarly, serum triglycerides were decreased in th e groups with higher AA intake. Liver AA concentration increased signi ficantly in accordance with rising AA doses. High AA intake (1000 mg/l ) for 10 weeks resulted in significant increase of both cytochromes P- 450 and cytochrome bg and total haeme content in liver microsomes when compared to guinea pigs with suboptimal AA intake. A significant posi tive correlation between hepatic AA concentration and cytochrome P-450 content was observed. A close negative correlation between liver tota l cholesterol and cytochrome P-450 content in hepatic microsomes was a lso seen. Long-term suboptimal AA intake may unfavourably alter the bl ood and liver lipid profile as well as the capacity of hepatic drug me tabolizing enzymes in both male and female guinea pigs.