Unspecific and specific stimulating effects of 3',5'-cyclic nucleotides (cGMP, cAMP, cIMP, cCMP) on the in vitro biosynthesis of proteochondroitin-4,-6-sulfate and on other anabolic processes from calf rib cartilage.

ABSTRACT

With cartilage slices from calf ribs, cGMP as well as cAMP accelerate dose-dependently and specifically label rates of Ch-4-,-6-S protein; they slightly elevate rates of anaerobic glycolysis dose-independently and unspecifically, similar to their 5-monophosphate compounds. cAMP, but not cGMP, slightly stimulates labeling of total protein dose-dependently. Guanosine and adenosine (as well as adenine) accelerate more significantly all three anabolic processes in the order Ch-4-,-6-S protein formation greater than or equal to total protein labeling greater than anaerobic glycolysis. Acceleration of some of the processes rises further after adding theophylline or SQ 20.009, depending on the nucleoside used. diBu-cAMP (but not 8-Br-cAMP) stimulates the three processes more than cAMP; diBu-cGMP and 8-Br-cGMP alone increase the labeling rates of protein more than cGMP, cCMP and cIMP slightly accelerate at least one of the three processes dose-independently and unspecifically, similar to their 5-monophosphate compounds. cUMP was almost inactive. The results point to specific and unspecific effects of cGMP similar or different to those of cAMP.