Distribution kinetics of inorganic mercury in the subcellular fractions of fish liver.

The present study tries to find out the kinetics of distribution of mercury in the different subcellular fractions of the liver in a freshwater perch Anabas testudineus over a period of 48 h after a single i.m. injection of [203Hg]mercuric nitrate at a dose of 4 mg/kg body weight. The fish were killed at 15 min, 2 h, 6 h and 48 h post injection. In addition the interaction of this metal with different biomolecules, viz., protein, DNA and RNA, was also investigated. Cytosol was found to be the major site of mercury accumulation. Moderate amounts of accumulation occurred in the nuclear, mitochondrial and microsomal fractions, although varying with time, while the lysosomal fraction did not reveal any spectacular retention of mercury. A significant increase in the protein content of nuclear, mitochondrial, lysosomal and cytosolic fractions was also noticed at different time periods of mercury injection. In the nuclear, microsomal and cytosolic proteins, mercury binding increased more significantly over time than the mitochondrial and lysosomal proteins. A biphasic binding pattern of mercury was seen in nuclear and mitochondrial DNA and mitochondrial and cytosolic RNA.