Fast cold-induced activation of the external pathway of NADH oxidation in liver mitochondria of hyperthyroid rats.
The exposure of a cold-adapted rat for 15 min at 4 degrees C results in the appearance of measurable oxidation of added NADH via the external amytal- and antimycin-A-resistant pathway in liver mitochondria. This effect increases if the animal has been treated with thyroid gland preparation for 4-5 days. In vitro, the addition of Mg2+ or increase in the tonicity of incubation mixture suppresses external NADH oxidation. Addition of 70 mg X ml-1 serum albumin or 70 mg X ml-1 polyvinylpyrrolidone in the presence of Mg2+ and addition of 20 microM palmitic or 20 microM oleic acids induces to some extent external NADH oxidation in the mitochondria of control (nontreated) and of cold-adapted, thyroidgland-preparation-treated rats. It is concluded that hyperthyroid rats can be used as a model of cold-induced initiation of the external pathway of NADH oxidation. A relation between the increase of exogenous NADH oxidation and phospholipase A2 activity in liver mitochondria is discussed.
D000654:Amobarbital / Q000494:pharmacology; D000818:Animals; D000968:Antimycin A / Q000494:pharmacology; D003080:Cold Temperature; D005260:Female; D006980:Hyperthyroidism / Q000378:metabolism*; D008274:Magnesium / Q000494:pharmacology; D008930:Mitochondria, Liver / Q000187:drug effects / Q000378:metabolism*; D009243:NAD / Q000378:metabolism*; D019301:Oleic Acid; D009829:Oleic Acids / Q000494:pharmacology; D010084:Oxidation-Reduction; D010101:Oxygen Consumption; D019308:Palmitic Acid; D010169:Palmitic Acids / Q000494:pharmacology; D051381:Rats; D012710:Serum Albumin, Bovine / Q000494:pharmacology; D013963:Thyroid Hormones / Q000494:pharmacology
D009829:Oleic Acids; D010169:Palmitic Acids; D013963:Thyroid Hormones; D009243:NAD; D012710:Serum Albumin, Bovine; D019301:Oleic Acid; D019308:Palmitic Acid; D000968:Antimycin A; C004227:thyroidin; D000654:Amobarbital; D008274:Magnesium