title: Differential response of articular chondrocyte populations to thromboxane B2 and analogs of prostaglandin cyclic endoperoxides.
abstract: The effects of two unsaturated fatty acids, protaglandin E2, thromboxane B2 (TxB2) and 2 analogs of PG endoperoxide on monolayer cultures of rabbit articular chondrocytes have been studied. Arachidonic and linoleic acids had no effect on either DNA or sulfated-glycosaminoglycan biosynthesis, while 13,14 dihydro-PGE2 and PGE2 markedly inhibited the former. Two epoxymethano analogs of endoperoxide PGH2 (Em-;pgh2) at concentrations of 2.5 and 24 microgram/ml stimulated cell proliferation while reducing 35SO4 incorporation. By contrast, Em-PGH2 at lower concentrations (0.25 - 250 ng/ml) inhibited DNA synthesis in a dose-dependent manner. TxB2 at 2.5 microgram/ml did not alter cellular proliferation. At lower concentrations, 2.5 and 25 ng/ml, TxB2 significantly stimulated sulfated-glycosaminoglycan biosynthesis in at least one of the chondrocyte populations tested. The results also demonstrated marked differences in the effects of TxB2 and the Em-PGH2 analogs on the partitioning of newly synthesized sulfated-proteoglycan between the cells and medium of these cell cultures.
mesh_terms: D000818:Animals; D001095:Arachidonic Acids / Q000494:pharmacology; D002358:Cartilage, Articular / Q000187:drug effects* / Q000378:metabolism; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D004247:DNA / Q000096:biosynthesis; D015232:Dinoprostone / Q000031:analogs & derivatives*; D006025:Glycosaminoglycans / Q000096:biosynthesis; D008041:Linoleic Acids / Q000494:pharmacology; D011450:Prostaglandin Endoperoxides, Synthetic / Q000494:pharmacology*; D011459:Prostaglandins E, Synthetic / Q000494:pharmacology; D011817:Rabbits; D013464:Sulfuric Acids / Q000096:biosynthesis; D013929:Thromboxane B2 / Q000494:pharmacology*; D013931:Thromboxanes / Q000494:pharmacology*
chemical_list: D001095:Arachidonic Acids; D006025:Glycosaminoglycans; D008041:Linoleic Acids; D011450:Prostaglandin Endoperoxides, Synthetic; D011459:Prostaglandins E, Synthetic; D013464:Sulfuric Acids; D013931:Thromboxanes; C013786:A73025; C025395:13,14-dihydroprostaglandin E2; D013929:Thromboxane B2; D004247:DNA; D015232:Dinoprostone