BACKGROUND: We examined the effect of excessive stress on the production of basic fibroblast growth factor (bFGF) by bovine cartilage.METHODS: Bovine articular carpal bone was harvested and cut into 1 cm thick slices horizontally. Continuous compressive stress (0, 2, 20 MPa) was loaded on the cartilage of the carpal bone using a stainless-steel cylinder with a diameter of 8 mm for 1 h. The slices were cultured immediately after compression, and the supernatant of the culture medium was collected for bFGF and nitric oxide (NO) measurement. Interleukin-4 (IL-4) or N(G)-monoethyl-L: -arginine (L: -NMEA) was added to the culture medium in some experiments.RESULTS: Basic FGF production was significantly increased after 36 h of cultivation without mechanical stress (0.40 +/- 0.03 microg/ml). In contrast, the bFGF concentration was not increased by compressive stress of 20 MPa after 36 h of cultivation. An NO inhibitor, L: -NMEA, did not alter the effect of compressive stress on the production of bFGF. IL-4 reduced the production of bFGF by cartilage with or without mechanical stress.CONCLUSIONS: Excessive stress on cartilage inhibits the production of bFGF in an NO-independent manner, and IL-4 plays an important role in the reduction of bFGF.
Animals Carpal Joints