Soluble factor from the hypertrophied left ventricle of dogs in experimental hypertension: ability to stimulate protein metabolism of cultured heart cells.

Abstract

Our study concerned the existence of humoral factor(s) in cardiac hypertrophy arising from experimental perinephritic hypertension in dogs. Hypertension was induced by the method of Page with some modifications. A microassay technique was used on cultured neonatal rat heart cells. Heart extract from the hypertrophied left ventricle of dogs with experimentally induced renal hypertension, but not sham-operated dogs, increased the uptake of 3H-uridine by cultured rat heart cells. At a final heart extract concentration of 5 X 10(-3)% v/v (1-3 micrograms/ml), 3H-uridine was increased by a mean of about 15%, from four experiments. High performance liquid chromatography showed that the heart extract contained at least 16 molecules. Among them, a molecule of approximately 11,200 molecular weight stimulated the uptake of both 3H-uridine and 14C-leucine by cultured rat heart cells. These results indicate that the heart extract from the hypertrophied left ventricle of dogs with experimentally induced renal hypertension contained a factor that might induce and/or modulate myocardial hypertrophy in the model of hypertension.