Effects of Cytochrome C on Lipid and Sugar Metabolism in Aged Rats

Abstract

Results of studies on actions of cytochrome c on the liver have been reported by the authors (1-4). In a previous report (4), a conclusion was reached that the improving action exhibited by cytochrome c on spontaneously decreasing liver function in aged rats results from the improvement of mitochondrial function and an increase in hepatic glutathione.In the present study, attempts have been made to determine the effects of aging on lipid and sugar metabolism as well as the effects of cytochrome c administration of lipid and sugar metabolism in aged rats showing spontaneous decrease in liver function. MATERIALS AND METHODSThe experimental materials and methods conformed to those described in the previ ous report (4). Equine cytochrome c was given to 500 day-old rats i.nn. into thigh or p.o.in the form of enteric-coated granules in a dose of 100 mg/kg for 21 consecutive days and biochemical studies were conducted in comparison with 70 and 250 day-old rats.Method of Lipid Determination: Total serum lipids, serum cholesterol and phospho lipids were measured by means of the Bragdon's oxidation method (5), the Zurkowsky's method (6) and the Hoeflmayer and Fried's method (7) respectively, whereas free fatty acid, triglyceride and f3-lipoprotein were measured by means of the Doncomb's method (8), the Van Handel's method (9) and the heparin calcium chloride sedimentaion method (10) respectively. In determining hepatic lipids, total lipids, cholesterol, phospholipids and neutral fat were measured by the same method as used in serum determinations by extracting lipids from a homogenate prepared by adding 9 ml. of 0.9 % aqueous sodium chloride to 1 g. of the liver with the use of a mixture of chloroform and methanol (2: 1).Analysis of Fatty Acid Composition: The fatty acid composition of the serum total lipids and the hepatic total lipids were analyzed by Higasa's method (11) and Takenaka's method (12), respectively.