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 may be a useful marker of collagen turnover, was examined in the serum of rats with implanted silicones. No significant difference in spectrofluorometrically determined enzyme activity was demonstrated in rats subjected to dorsal submuscular pocket dissection without implantation and corresponding nonoperative controls. Rats with implanted solid silicone elastomer or free polydimethylsiloxane gel (both components obtained from mammary implant) revealed enhanced activity of serum beta-GAL. Higher enzyme activity was observed in animals with implanted silicone gel with a peak level of 2.73 +/- 0.08 pmol/30 min/ml 16 weeks after implantation. Increased collagen deposition and capsular thickness was demonstrated around implanted gel material as compared with that around elastomer shell. Animals with implanted absorbable and nonabsorbable materials, polyglactin and Teflon (polytetrafluoroethylene), respectively, after initial increase of beta-GAL activity demonstrated enzyme activity within the normal range. Findings indicate that there is enhanced lysosomal beta-GAL activity after silicone implantation in rats. Clinical relevance and its possible significance as a predictor or indicator of local or systemic fibrosis after silicone implantation seems worthy of further investigation.