Pathologic findings and laboratory data in a new strain of obese hypertensive rats.

A new strain of rat characterized by genetic obesity, endogenous hyperlipidemia, and hypertension was obtained in this laboratory. The abnormal phenotype is inherited as a homozygous recessive trait. The animals exhibit marked hypertriglyceridemia, moderate hypercholesterolemia, and an electrophoretic pattern resembling that of human Type IV hyperlipoproteinemia. The average life-span is less than 1 year, due largely to the development of premature renal and vascular disease. The kidney lesion has both glomerulonephritic and nephrosclerotic components and is accompanied by marked proteinuria. About 12% of animals develop urinary tract calculi. The vascular disease consists of fibrous and fatty-fibrous intimal plaques, and polyarteritis. The obese animal offers a useful model for investigating abnormal lipid metabolism and the etiology and pathogenesis of atherosclerosis.