Evidence that endogenous cyclic AMP does not modulate serum sulfation factor action on embryonic chicken cartilage

The role of cartilage cyclic AMP as a mediator or modulator of serum sulfation factor (SSF) action on embryonic chicken cartilage was assessed. Media with concentrations of rat serum (7.5%) sufficient to maximally stimulate chondromucoprotein synthesis as measured by 35SO 4 incorporation did not change cartilage cyclic AMP levels. Theophylline (2.5mM) doubled cyclic AMP in cartilage incubated in media but had no effect on 35SO 4 incorporation. In media containing 5% rat serum, theophylline at 0.5, 1.5 and 2.5mM caused a similar and significant rise in tissue cyclic AMP but only 2.5mM inhibited SSF stimulated 35SO 4 incorporation. The data indicate that cartilage cyclic AMP neither mediates nor modulates SSF action on cartilage chondromucoprotein synthesis.