Androgenic regulation of enzymes involved in DNA synthesis in epididymis of young rats.
In the epididymis of young rats, activities of DNA polymerases alpha, beta and gamma and DNA topoisomerase I decreased after castration. DNA polymerase alpha and gamma increased with androgen administration and activity reached 81.3% and 78.0%, respectively, of the activity in the sham-operated group on day 21. Activity of DNA polymerase beta remained at the activity of day 7 during androgen administration and was almost the same as that in the sham-operated group on day 21. DNA topoisomerase I activity showed a slight increase with androgen administration and reached 50.3% of that in the sham-operated group. The activities of these enzymes were not fully restored to those in the sham-operated group. These results indicate that in young rats activities of epididymal DNA polymerase alpha and gamma and DNA topoisomerase I are partially, and that of DNA polymerase beta wholly, dependent on androgens and may provide a means of investigating the regulation of epididymal cell proliferation.
Imanishi
O
O
Department of Urology, Kobe University School of Medicine, Japan.
Fujisawa
M
M
Matsumoto
O
O
Kamidono
S
S
D000728:Androgens / Q000502:physiology*; D000818:Animals; D004247:DNA / Q000096:biosynthesis*; D004256:DNA Polymerase I / Q000378:metabolism; D004257:DNA Polymerase II / Q000378:metabolism; D004258:DNA Polymerase III / Q000378:metabolism; D004264:DNA Topoisomerases, Type I / Q000378:metabolism; D004259:DNA-Directed DNA Polymerase / Q000378:metabolism*; D004822:Epididymis / Q000378:metabolism*; D008297:Male; D009919:Orchiectomy; D051381:Rats; D017208:Rats, Wistar
D000728:Androgens; D004247:DNA; D004256:DNA Polymerase I; D004257:DNA Polymerase II; D004258:DNA Polymerase III; D004259:DNA-Directed DNA Polymerase; D004264:DNA Topoisomerases, Type I