Failure of tachykinins including substance P and its fragments to influence proteoglycan and protein synthesis in bovine chondrocytes in vitro.

Adult bovine articular chondrocytes were exposed to substance P, neurokinins A and B or substance P fragments, SP1-4, SP1-6 and SP7-11 in vitro. Proteoglycan synthesis was assessed by measuring proteoglycans which were released into the culture medium or incorporated into the cell layer. The intact tachykinins or substance P fragments had no direct effect on proteoglycan synthesis. Nor was total protein production affected. Gel chromatography, under dissociative conditions, revealed that sulphated proteoglycans detected in the medium or cell layer following treatment of chondrocytes with substance P, contained proteoglycans of similar molecular weight to those produced by cells exposed only to diluent controls. Therefore, we conclude that the acceleration of arthritis by substance P does not appear to be mediated through an effect on chondrocyte synthetic function.