HEART MUSCLE CATECHOLAMINES AND ENZYMES IN EXPERIMENTAL THYROID DISEASES

(1) Heart muscle catecholamine content, pseudocholinesterase activity, and glutamic oxaloacetic transaminase and glutamic pyruvic transaminase activities were measured in rats after administration of 3, 5, 3' triiodothyronine and 1-methy 1-2-mercaptoimidazole in order to find further correlations between these and the effects of thyroid hormones. Heart muscle adrenaline content significantly decreased in hyperthyroid group compared with hypothyroid and coutrol group. The significance of this finding in explaining hypersensitivity of adrenaline in hyperthyroidism was discussed. The metabolism of catecholamines in relation to this finding was also discussed.(2) Pseudocholinesterase activity in the heart muscle significantly increased in hyperthyroid group and decreased in hypothyroid group compared with control group. Its possible significance in thyroid diseases was discussed.(3) Glutamic oxaloacetic transaminase and glutamic pyruvic transaminase activities in the heart muscle significantly decreased in hyperthyroid as well as hypothyroid group compared with control group. It is likely that muscular involvements in thyroid diseases are significant enough to cause possible liberation of these enzymes.