ABSTRACT
This study was conducted to investigate the effect of a new phosphorothionate, the methyl ester of 2-butenoic acid-3-diethoxy phosphinothioyl (RPR-II) on membrane bound target enzymes aspartate amino transferase (ASAT), alanine amino transferase (ALAT) and RBC acetylcholinesterase (AChE) in different tissues of male and female albino wistar rats when treated orally with 0.014 (low), 0.028 (medium) and 0.042 (high) mg/kg daily for a period of 90 days. Repeated administration of RPR-II caused significant increase of ASAT and ALAT enzymes in serum, liver and kidney and significant decrease was recorded in lung in both male and female rats when measured after 45 and 90 days of treatment. This compound also caused significant inhibition of RBC AChE indicating its effect on nerve synapsis. Females were more susceptible than males with regard to ASAT and ALAT levels in serum and liver and also in kidney ASAT, whereas reverse trend was recorded in lung ALAT, suggesting sexual dimorphism in the treated rats. These studies also indicated that the levels of these affected enzymes were recovered to normal conditions after 28 days of post treatment (withdrawal study). Positive correlation was observed with regard to these enzymes between serum, liver and kidney, whereas in case of serum and lung a negative correlation was recorded. These enzymes profile elucidates lung necrosis whereas in other tissues the level of enzymes increased showing an adaptive mechanism due to the chemical stress.