ENHANCED ACTIVITY OF LYSOSOMAL BETA-GALACTOSIDASE AFTER SILICONE IMPLANTATION - AN EXPERIMENTAL-STUDY IN RATS

Biologic consequences of silicone implantation may include changes in host connective tissue metabolism. Lysosomal beta-galactosidase (beta- GAL) activity, which is a sensitive marker of fibrotic diseases and ma y be a useful marker of collagen turnover, was examined in the serum o f rats with implanted silicones. No significant difference in spectrof luorometrically determined enzyme activity was demonstrated in rats su bjected to dorsal submuscular pocket dissection without implantation a nd corresponding nonoperative controls. Rats with implanted solid sili cone elastomer or free polydimethylsiloxane gel (both components obtai ned from mammary implant) revealed enhanced activity of serum beta-GAL . Higher enzyme activity was observed in animals with implanted silico ne gel with a peak level of 2.73 +/- 0.08 pmol/30 min/ml 16 weeks afte r implantation. Increased collagen deposition and capsular thickness w as demonstrated around implanted gel material as compared with that ar ound elastomer shell. Animals with implanted absorbable and nonabsorba ble materials, polyglactin and Teflon (polytetrafluoroethylene), respe ctively, after initial increase of beta-GAL activity demonstrated enzy me activity within the normal range. Findings indicate that there is e nhanced lysosomal beta-GAL activity after silicone implantation in rat s. Clinical relevance and its possible significance os a predictor or indicator of local or systemic fibrosis after silicone implantation se ems worthy of further investigation.