A DNA topoisomerase I inhibitor blocks the differentiation of rat granulosa cells induced by follicle-stimulating hormone.
Follicle-stimulating hormone (FSH), acting through a cycle AMP-mediated mechanism, promotes differentiation of rat granulosa cells cultured in a defined medium. Camptothecin, a DNA topoisomerase I blocker, inhibited the increase in progesterone and oestradiol production stimulated by FSH. This effect was not due to non-specific inhibition of protein synthesis, as shown by measurement of [35S]methionine incorporation. A transient increase in DNA topoisomerase I activity was observed after 24 h of culture in the presence of FSH or dibutyryl cyclic AMP. Our results are consistent with a key role for DNA topoisomerase I in the modulation of gene expression by FSH in rat granulosa cells.
Barañao
J L
JL
Instituto de Biología y Medicina Experimental, (Consejo Nacional de Investigaciones Científicas y Técnicas), Buenos Aires, Argentina.
Bley
M A
MA
Batista
F D
FD
Glikin
G C
GC
D000818:Animals; D003994:Bucladesine / Q000494:pharmacology; D002166:Camptothecin / Q000494:pharmacology*; D002454:Cell Differentiation / Q000187:drug effects*; D002478:Cells, Cultured; D004264:DNA Topoisomerases, Type I / Q000378:metabolism*; D004054:Diethylstilbestrol / Q000494:pharmacology; D005260:Female; D005640:Follicle Stimulating Hormone / Q000494:pharmacology*; D006107:Granulosa Cells / Q000166:cytology* / Q000187:drug effects / Q000201:enzymology; D007328:Insulin / Q000494:pharmacology; D007700:Kinetics; D008715:Methionine / Q000378:metabolism; D014176:Protein Biosynthesis; D051381:Rats; D011919:Rats, Inbred Strains; D059004:Topoisomerase I Inhibitors
D007328:Insulin; D059004:Topoisomerase I Inhibitors; D003994:Bucladesine; D004054:Diethylstilbestrol; D005640:Follicle Stimulating Hormone; D008715:Methionine; D004264:DNA Topoisomerases, Type I; D002166:Camptothecin