monensin and Malnutrition

We investigated the effect of high (12, 20, and 50 mM) extracellular K+ concentrations ([K+]0) on [U-14C] acetate oxidation to CO2 in cerebral cortex slices of control and perinatal malnourished rats. High [K+]o increased the acetate oxidation, compared with a medium containing 2.7 mM [K+]0. By investigating the mechanisms involved in this stimulation, it was shown that (i) ouabain (1 mM) and monensin (10 microM) prevented this increase; (ii) in a medium with physiological [K+]0 (2.7 mM), the decreasing of [Na+]0 stimulated acetate oxidation. These results suggest that the stimulatory effect of [K+]0 on acetate oxidation was due to the decreasing of Na1 levels. Considering that malnutrition could alter the activity of Na+,K(+)-ATPase and/or other pertinent proteins, its effect on acetate oxidation was investigated. The malnutrition, which altered the body and cerebral weight of rats, did not modify the acetate oxidation in any protocol.

Topics: Acetates; Animals; Body Weight; Brain; Cerebral Cortex; Female; Malnutrition; Monensin; Ouabain; Oxidation-Reduction; Potassium; Pregnancy; Prenatal Exposure Delayed Effects; Rats; Rats, Wistar; Reference Values