Inhibin and activin regulate [3H]thymidine uptake by rat thymocytes and 3T3 cells in vitro.
[3H]Thymidine incorporation by adult rat thymocytes, in the presence of phytohaemagglutinin (PHA), was stimulated by bovine inhibin (ED50 0.7 nM), and inhibited by bovine activin (ID50 0.4 nM) and porcine transforming growth factor-beta (TGF-beta) (ID50 4 pM); inhibin opposed the actions of activin and TGF-beta. Bovine 35 kDa follicle stimulating hormone (FSH) suppressing protein (FSP) had no effect on either unstimulated or PHA-stimulated thymocytes. Inhibin also stimulated thymocytes in the presence of a submaximal dose of concanavalin A (ConA), and in the absence of either lectin. Thymocytes which had been maximally stimulated by ConA were inhibited by TGF-beta (ID50 0.02 nM), but not affected by inhibin and activin. Both activin and TGF-beta stimulated [3H]thymidine uptake by 3T3 fibroblasts, but inhibin and FSP had no effect, alone or on activin-stimulated 3T3 fibroblasts. The results indicate that inhibin and activin have opposing, cell type-specific effects on the proliferation of T-lymphocytes, while activin also stimulates fibroblast proliferation in vitro.
Hedger
M P
MP
Department of Anatomy, Monash University, Clayton, Victoria, Australia.
Drummond
A E
AE
Robertson
D M
DM
Risbridger
G P
GP
de Kretser
D M
DM
D000818:Animals; D002455:Cell Division / Q000187:drug effects; D002460:Cell Line; D003208:Concanavalin A / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D005640:Follicle Stimulating Hormone / Q000494:pharmacology; D007265:Inhibins / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D008297:Male; D051379:Mice; D010835:Phytohemagglutinins / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D013936:Thymidine / Q000378:metabolism*; D013950:Thymus Gland / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D015291:Transforming Growth Factors / Q000494:pharmacology
D010835:Phytohemagglutinins; D003208:Concanavalin A; D007265:Inhibins; D015291:Transforming Growth Factors; D005640:Follicle Stimulating Hormone; D013936:Thymidine