Inhibitory and stimulating effects of various types and series of prostaglandins on in vitro biosynthesis of proteochondroitin-4,6-sulfate and protein and anaerobic glycolysis in calf rib cartilage.

The effect of various types of prostaglandins (PGs) have been studied in a semi-in-vitro system with cartilage slices of calf ribs. 0.1 mmol/1 PG B1, D2, E1, E2, F1 alpha, F2 alpha inhibit biosynthesis of Ch-4,6-S protein to a higher extent than 10 mumol/l; 1 and 2 series PG E and F (but not B) inhibit similarly, PG A2 inhibits twice as much. With biosynthesis of total protein 2-series PG A, B, E, F act more inhibitorily than 1-series PG. 10 mumol/l PG A2, E1, E2 produce cAMP-like effects, e.g. acceleration of biosynthesis of Ch-4,6-S protein and total protein as well as of anaerobic glycolysis; PG F2 alpha stimulates the first two anabolic processes, PG B1 only the second one. PG A1 stimulates Ch-4,6-S protein biosynthesis and anaerobic glycolysis, a cGMP-like effect. 20 mumol/l diBu-cAMP or cAMP (together with 0.1 mmol/l theophylline) produce stimulating and inhibitory effects on these three anabolic processes; both compounds produce additively positive or additively negative effects in connection with the inhibitory PG effects on these three anabolic processes.