The effects of nutrition on plasma cholinesterase activity and cocaine toxicity in mice

Background: Low plasma cholinesterase activity is associated with severe co caine toxicity in human subjects and animal experiments. Exogenously enhanc ed plasma cholinesterase activity is protective against cocaine toxicity in animals, Cocaine users tend to have tower plasma cholinesterase activity t han controls. Yet, when cocaine users are allowed to use cocaine in control led settings without dietary restriction, their plasma cholinesterase activ ity increases. This study evaluates the influence of diet on plasma choline sterase activity and cocaine toxicity. Methods: Forty-five Swiss albino mic e were maintained on a high (30%) protein diet for 3 weeks. They were then randomized into equal groups and given either the high protein diet, an iso caloric low protein diet, or a protein and calorie deficient diet which con sisted of reduced intake of the high protein diet. Body weights and plasma cholinesterase activities were measured after a 21-day study period. All an imals then received a fixed dose of intraperitoneal cocaine and were observ ed for seizures and death. Results: Body weights and plasma cholinesterase activities of the high protein animals remained stable. Weights for the low protein and reduced intake animals fell by 5% and 15%, respectively (p < 0 .05 for both vs baseline), Similarly, plasma cholinesterase activities for the low protein and reduced intake animals fell by 4% and 10%, respectively (p = 0.06 for low protein and < 0.05 for reduced intake vs baseline). Coca ine caused seizures in 67% of the high protein animals as compared to 93% a nd 100% of the low protein and reduced intake animals, respectively (p < 0. 05 for high protein vs reduced intake). None of the high protein animals di ed as compared to 20% and 100% of the low protein and reduced intake animal s, respectively (p < 0.05 for high protein vs reduced intake). Conclusion: Protein and calorie malnutrition is associated with a reduction in plasma c holinesterase activity and enhanced cocaine toxicity in mice. Further study is needed to determine if dietary factors are partially responsible for va riations in plasma cholinesterase activity and cocaine susceptibility in hu mans.