STRONG EXPRESSION OF HEAT-SHOCK PROTEINS IN GROWTH-PLATE CARTILAGE, AN IMMUNOHISTOCHEMICAL STUDY OF HSP28, HSP10 AND HSP110

Heat shock proteins (HSPs) are known to be increased in response to st resses. Our immunohistochemical investigations revealed the strong exp ression of a wide range of HSPs in the chondrocytes of the tibial grow th plate cartilage from young rats. HSP28 and HSP70 are expressed in t he upper part of the hypertrophic zone of the growth plate cartilage. HSP110 are found from the proliferating zone to the hypertrophic zone. On the other hand, application of the TUNEL method has already shown apoptotic DNA fragmentation in the lower part of the proliferating zon e. From then one, HSP expression in the chondrocytes may be correlated with apoptosis, but its possible relation with the different events o ccurring during the calcification process cannot be excluded.