Liver Regeneration in Oral Contraceptive Treated Female Rats - Effects of Moderate Malnutrition

Summary

Treatment of well-nourished female rats with a combination of 5 μg ethynyl estradiol and 100 μg ethynodiol diacetate, increased the DNA content, ³H thymidine incorporation into DNA and mitotic activity in the non-regenerating liver, but impaired liver regeneration after partial hepatectomy. In rats which were moderately malnourished by feeding 25 percent less calories and 50 percent of recommended allowance for vitamins A and B₂, OC treatment had similar stimulatory effect on non-regenerating liver, but did not impair liver regeneration after partial hepatectomy.

Analysis of nucleotide bases after hydrolysis of unpolymerised nucleotides and nucleosides revealed significant perturbations due to OC treatment. However, the impaired liver regeneration due to OC treatment of wellnourished rats could not be attributed to diminished availability of bases, particularly thymidine. Data on mitotic index and binucleate cell numbers suggest that besides inhibiting mitosis (DNA duplication), OC treatment of well-nourished rats may also impair partitioning of binucleate cells.

Key-Words:

Oral Contraceptive - Liver Regeneration - Calorie Deficiency - Vitamin Deficiency - Liver Nucleic Acids - Nucleotide Bases - Thymidine Incorporation - Liver Protein - Binucleate Cells - Mitotic Index