EXPERIMENTAL CARDIAC HYPERTROPHY: RATE OF DEVELOPMENT AND EFFECT OF ADRENALECTOMY

Abstract

In albino rats subjected to the Grollman technic for inducing hypertension (unilateral nephrectomy and figure-of-8 ligature around the pole of the remaining kidney), cardiac hypertrophy developed rapidly. In a series of animals killed in groups at intervals of 2-120 days postoperatively, a significant increase in heart wt. appeared as early as 2 days, and half of the ultimate increase in heart wt. was reached in 10 days. No significant progression of hypertrophy occurred after 40 days. Three of 8 surviving rats at 120 days had developed fibrinoid arteritis of the perarteritis nodosa type, involving extrarenal vessels of 200-1000 u. in diam. None of the animals developed glomerular sclerosis or necrotizing arteriolitis of the type seen in malignant hypertension. Control series of sham-operated and unilaterally nephrectomized rats were used. Comparably prepared rats subjected also to bilateral adrenalectomy showed significant cardiac hypertrophy at 10 days but at 20 days the hearts of these animals were only slightly larger than those of control rats. It is suggested that in the adrenalectomized animals the hypertensive load was not maintained.