Effect of Escherichia coli endotoxin on adenine nucleotide translocation in canine heart mitochondria

Mitochondrial function in shock

Studies utilizing animal models of circulatory shock have revealed mitochondrial structural and functional damage in the liver, kidney, and brain. Adenosine triphosphate (ATP) synthesis and calcium transport rates of these mitochondria decline significantly during circulatory shock. The specific enzyme functions affected deleteriously by low flow states are the ATP synthetase, adenine nucleotide translocase, and carrier-mediated calcium transport. Other cellular alterations that possibly are responsible for, or are related to, the shock-induced mitochondrial deterioration are discussed. Differences in the mitochondrial responses to endotoxemia and hyperdynamic sepsis are described. Data are presented on the beneficial effects of early glucocorticoid treatment in prevention of mitochondrial functional deterioration during endotoxemia.

Respiratory activities of subsarcolemmal and intermyofibrillar mitochondrial populations isolated from denervated and control rat soleus muscles

Ultraturrax and Nagarse released populations of mitochondria isolated from control and day 21 denervated rat soleus muscle were characterized with respect to their oxidative phosphorylation, ADP translocase and ATPase activities. Both Ultraturrax and Nagarse released mitochondrial populations displayed lower capacities for oxidative phosphorylation; lower ADP translocase activities and higher Mg2+ stimulated ATPase activities than their corresponding controls. For both the denervated and control states, the Nagarse-released mitochondrial populations displayed significantly higher respiratory activities than the Ultraturrax released fractions. The significance of these findings is discussed with regard to the process of mitochondrial respiratory control. In addition the role of mitochondrial dysfunction in denervation muscular atrophy is assessed.