SODIUM FLUORIDE ALTERATION OF PROTEIN CONTENT VIS-À-VIS ELECTROPHORETIC PATTERN OF MUSCLE ESTERASES (E.C.3.1.1.1) IN POECILIA RETICULATA PETERS ON CHRONIC EXPOSURE

ABSTRACT: A progressive reduction in protein content observed in the muscle of fish in present study was both as a function of time as well as increase in the concentration of fluoride. During chronic exposure to sodium fluoride, the banding pattern of esterase diminished in the treated group of fish viz. lowest (5.75 ppm), lower intermediate (7.18 ppm), higher intermediate (9.58 ppm) and highest (14.37 ppm) concentration of the 24 hrs. LC 50 (115 ppm) value when compared with the control group. SDS-PAGE and staining of the gel revealed that esterase in muscle of fish from control group resolved into six bands (lane-1). Exposure of fluoride to all the four concentrations showed significantly faint and diffused banding pattern of esterases and complete loss of esterase band-1 (Lane 2-5), probably due to chronic stress induced by fluoride. The esterase from band-1 might be sensitive to fluoride intoxication, thus completely vanished during chronic treatment. However in the higher intermediate (9.58 ppm) and highest (14.37 ppm) sodium fluoride treatment groups, sixth band of esterase (lane 4-5) was found to be very faintly visible on staining. Decrement in protein content & diminution of certain esterase bands in the muscle tissue of the treated group suggest soft tissue (non-skeletal) fluorosis induced by sodium fluoride during chronic exposure period, probably could be due to inhibition of biosynthetic mechanism of proteins vis-a-vis esterases. The study of esterase in fish calls attention to sensitive indicator of the environmental pollutants and can be used as contrivance in study of environmental dilapidations. KEY WORDS: Protein, Esterase isozymes, Electrophoresis, Sodium fluoride, Poecilia reticulata.