Changes in brain mitochondrial bioenergetics in protein-deficient rats.

An assessment of mitochondrial bioenergetics in protein-malnourished rats indicates that there is a reduction of brain mitochondrial metabolism in protein malnutrition. Specifically, mitochondria of protein-malnourished offspring of malnourished rats exhibit (i) an enhancement of state 4 respiration, (ii) a reduction of ADP-stimulated state 3 respiration, (iii) a decrease in ADP:O ratios, (iv) reductions of FCCP-induced ATPase action and in the rates of proton and calcium ion translocation, and (v) diminished activities of redox enzymes. In general, these changes are less pronounced in malnourished weanling rats born of healthy dams. Although the exact molecular mechanism of these defects is not yet known, the alterations are definitely caused by diet-induced changes in the structure and integrity of inner mitochondrial membrane components.