Stimulation of cyclic AMP in chondrocyte cultures: effects on sulfated-proteoglycan synthesis.
The effects of N6,O2'-dibutyryladenosine 3':5'-cyclic monophosphate (DBcAMP), 8-bromoadenosine 3':5'-cyclic monophosphate (8Br-cAMP), 3':5'-cyclic monophosphate (cAMP), L-isoproterenol and L-epinephrine on sulfated-proteoglycan synthesis by rabbit articular chondrocytes were compared. DBcAMP and 8Br-cAMP in the presence or absence of 3-isobutyl-1-methylxanthine (IBMX) stimulated sulfated-proteoglycan biosynthesis after 20 h of incubation. cAMP had no significant effect. Both DBcAMP and 8Br-cAMP increased the hydrodynamic size of the newly synthesized proteoglycan monomer (A1D1) relative to control cultures. By contrast, although isoproterenol and epinephrine stimulated total cAMP synthesis, neither stimulated sulfated-proteoglycan synthesis. Whereas intracellular cAMP accumulated after incubation with DBcAMP and 8Br-cAMP, this was not the case with isoproterenol whether IBMX was present or not. Thus, stimulation of sulfated-proteoglycan synthesis by cAMP analogues in chondrocyte cultures appears to be dependent on increased intracellular cAMP accumulation rather than total cAMP biosynthesis.
D015124:8-Bromo Cyclic Adenosine Monophosphate / Q000494:pharmacology; D000818:Animals; D003994:Bucladesine / Q000494:pharmacology; D002358:Cartilage, Articular / Q000187:drug effects / Q000378:metabolism*; D002478:Cells, Cultured; D000242:Cyclic AMP / Q000502:physiology*; D004837:Epinephrine / Q000494:pharmacology; D007545:Isoproterenol / Q000494:pharmacology; D011509:Proteoglycans / Q000096:biosynthesis*; D011817:Rabbits
D011509:Proteoglycans; D015124:8-Bromo Cyclic Adenosine Monophosphate; D003994:Bucladesine; D000242:Cyclic AMP; D007545:Isoproterenol; D004837:Epinephrine