Respiration and phosphorylation of mitochondria isolated from the skeletal muscle of diabetic and normal subjects

Abstract

A group of diabetics, well controlled as far as blood sugar, free fatty acids and acetoacetate were concerned but with a high frequency of diabetic angiopathy in different organs, was compared with a group of controls in terms of the respiration and phosphorylation reactions in mitochondria isolated from skeletal muscle. Two keto-acidotic patients were also studied. The reactions studied were: respiration with glutamate or pyruvate plus malate as substrates, and also ratios of esterified inorganic orthophosphate to oxygen consumed and respiratory control with these substrates. The respiratory control in the absence of adenosine triphosphate was measured for pyruvate plus malate, and also the influence of serum albumin on this. Adenosine triphosphatase was measured under basal conditions and after maximal activation with 2,4-dinitrophenol. No certain differences were found between the non-ketotic diabetics and controls. Caution must be exercised in the interpretation of certain of the results because of difficulties in standardization of the mitochondrial isolation procedure in a patient material with wide ranges of age, infiltration of fibrous material in muscles, atrophy of muscles and other factors. © 1967 Springer-Verlag.