Stimulation of 86Rb+ and 32Pi movements in 3T3 cells by prostaglandins and phorbol esters

✍ Scribed by J. Moroney; A. Smith; L. D. Tomei; C. E. Wenner

• Publisher: John Wiley and Sons
• Year: 1978
• Tongue: English
• Weight: 741 KB
• Volume: 95
• Category: Article
• ISSN: 0021-9541
• DOI: 10.1002/jcp.1040950306

✦ Synopsis

The potent tumor promoter tetradecanoyl phorbol acetate (TPA) induces early changes in ion movements analogous to those induced by prostaglandins El and Fz,. Among the earliest changes induced by TPA is a significant increase in 32PI incorporation within 15 minutes incubation of TPA (10-8-10-6 M) with post-confluent Swiss 3T3 mouse embryonic fibroblasts. Similarly, the active phorbol ester homolog 4-P-OH phorbol didecanoate but not the inactive stereoisomeric 4-a-OH phorbol didecanoate stimulated 32P1 incorporation. Also, TPA a t the above concentrations stimulated s6Rb+ influx shortly after administration. Both fluxes were ouabain-sensitive in accord with the idea that an early effect of TPA is to alter (Na' + K+)-ATPase activity. Further, prostaglandin El (10-7-10-6 M) and prostaglandin Fz, (3 X 10-9-10-7 M) caused a similar stimulation of 86Rb+ and 32PI uptake. The finding that watersoluble prostaglandin Fz, also exhibited stimulatory effects indicated that those hormone-induced responses are not mediated by solvent interactions. The similar responses of phorbol esters and prostaglandin derivatives suggests that phorbol esters and prostaglandin derivatives may act a t common membrane sites.

The finding that stimulatory effects were observed a t discrete times in the logarithmic phase of growth suggests that the activation of membrane receptors may be cell-cycle dependent.