Interactions between hepatic ascorbic acid, cytochrome P-450 and lipids in female guinea pigs with different ascorbic...

Changes in serum and liver lipids, hepatic ascorbic acid (AA) and cytochrome P-450 were investigated in female guinea pigs divided into three groups with different AA intake in drinking water (10, 100 and 1000 mg AA per liter) for 10 weeks. Serum and liver total cholesterol significantly decreased in guinea pigs receiving 100 and 1000 mg AA per liter of drinking water when compared with guinea pigs with suboptimal AA intake (10 mg/l). Similarly, serum triglycerides were decreased in the groups with higher AA intake. Liver AA concentration increased significantly 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 b5 and total haeme content in liver microsomes when compared to guinea pigs with suboptimal AA intake. A significant positive correlation between hepatic AA concentration and cytochrome P-450 content was observed. A close negative correlation between liver total cholesterol and cytochrome P-450 content in hepatic microsomes was also seen. Long-term suboptimal AA intake may unfavourably alter the blood and liver lipid profile as well as the capacity of hepatic drug metabolizing enzymes in both male and female guinea pigs.