Effects of thymulin on in vitro incorporation of 3H-thymidine into gonocytes of newborn rat testes.
3H-Thymidine incorporation into gonocytes was investigated by means of quantitative autoradiography in organ cultures of testes from newborn rats between day 0 (day of birth) and day 7, in the presence or absence of thymulin. The data indicated that thymulin had no effect on gonocyte incorporation on day 0 or on days 1 and 7; in contrast, thymulin had a strong effect on day 2. At day 2 the percentage of labeled gonocytes was 10-fold higher in experimental animals than in controls. Between days 2 and 6, thymulin had moderate activity. Thymulin thus appeared to have an age-dependent effect upon incorporation of 3H-thymidine into germ cells. On the other hand, in spite of a high incorporation rate of 3H-thymidine into gonocytes after incubation with thymulin, the number of mitoses remained low, suggesting that thymulin may affect DNA duplication in gonocytes of newborn rat testes.
Prépin
J
J
Département de Cytologie et Histologie, UFR Biomédicale des Saints-Pères, Paris, France.
Le Vigouroux
P
P
Dadoune
J P
JP
D000367:Age Factors; D000818:Animals; D000831:Animals, Newborn; D002455:Cell Division / Q000187:drug effects; D004261:DNA Replication / Q000187:drug effects*; D008297:Male; D009924:Organ Culture Techniques; D051381:Rats; D017208:Rats, Wistar; D013090:Spermatocytes / Q000187:drug effects* / Q000378:metabolism; D013737:Testis / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D013935:Thymic Factor, Circulating / Q000494:pharmacology*; D013936:Thymidine / Q000378:metabolism*; D014316:Tritium
D014316:Tritium; D013935:Thymic Factor, Circulating; D013936:Thymidine