Abstract

VARIATIONS IN LYSOSOMAL ENZYMES OF UTERINE EPITHELIAL/STROMAL CELLS DURING PRE-IMPLANTATION PERIOD IN RAT UNDER CDRI-85/287

K. Singh, G. Gupta, F. W. Bansode* and J. D. Dhar

Abstract

Lysosomal enzymes play a pivotal role in uterine growth/proliferation, epithelial cellular destruction/programmed cell death during implantation and decidualization. However, exact role of uterine epithelial/stromal cells in triggering various biochemical and hormonal events during blastocyst-implantation is not yet clear. The present study was conducted to determine the lysosomal enzymes viz. Leucine aminopeptidase (LAP), cathepsin D and phospholipase A2 (PLA2) activity in uterine fractions viz. luminal washings(LW), epithelium(UE) and stroma(US) during pre-implantation days 3-5 postcoitum (p.c.) under the influence of CDRI 85/287 (2.5 mg/Kg, p.o.; on day 1 p.c.), an estrogen antagonist and antiimplantation agent. Results revealed the differential pattern of lysosomal enzymes activity in different uterine cells fractions. While the LAP activity showed a decrease on day 4 vs. day 3 p.c., it increased on day 5 p.c. in all uterine fractions (LW, UE and US). The activity of cathepsin D increased to maximum on day 4 p.c. but showed decrease on day 5 in LW from control rats. Uterine epithelial activity showed an increase from day 3-5 p.c., but, there was a decline in stromal enzyme activity from days 3-5 p.c. Uterine PLA2 activity showed an increasing trend from day 3-5 p.c. Administration of CDRI 85/287 (2.5 mg/Kg) caused significant decline in lysosomal enzymes (LAP, Cathepsin D and PLA2) in LW, UE and US fractions on days 3, 4 and 5 as compared to corresponding controls. Results of the study show significant inhibition of lysosomal enzyme activity in all the uterine fractions under the influence of CDRI 85/287 indicating inhibition of implantation associated uterine growth and decidual cell transformation may be possibly due to antiestrogenic mode of action of the compound. Results are discussed in relation to alterations caused in uterine pregnancy-specific „key‟ lysosomal enzymes under the influence of this novel molecule.

Keywords: Lysosomal enzymes, LAP, Cathepsin D, PLA2, Uterus, CDRI-85/287.