The Expression of Peroxidase Superfamily Gpo and Lpo Enzymes in Rat Lacrimal Gland

Abstract

Purpose: : Peroxidase superfamily enzymes activity are being used as biomarkers of tears expression and action. However, the specific role of different peroxidases was never explored in exocrine glands. The aim of this study is to identify and distinguish the members of peroxidase superfamily in rat lacrimal gland

Methods: : Male and female Wistar rats lacrimal glands (LG) were homogenized and evaluated by Western blot to compare the expression of glutathione peroxidase-3 (GPO3) and lactoperoxidase (LPO). Total peroxidase activity was also compared among the groups.

Results: : Western blot analysis had shown that GPO3 and LPO proteins were expressed in LG. GPO3 expression was significantly reduced in LG of female compared to male (P<0.05), however LPO was significantly higher in LG of female rats (P<0.05). Total peroxidase activity was 0.29 mU/ml in male and 0.98 mU/ml in female rat lacrimal gland (P=0.0022).

Conclusions: : The present work shows that LPO expression is higher in LG of female rats. This data reveals that peroxidase activity in LG is exerted by different enzymes. Moreover, it suggests that peroxidase activity as measured by enzymatic assays express better the secretory function rather than antioxidant capacity. In further studies our group will explore the influence of environmental and intracellular variables in those enzymes to estimate the potential utility peroxidases in therapeutic strategies.

Keywords: lacrimal gland • enzymes/enzyme inhibitors