Effects of Unilateral Nephrectomy on Erythrocytosis and Arteriosclerosis Induced in Rats by Intrarenal Injection of Nickel Subsulfide

Administration of Ni3S2 to rats by unilateral inrarenal (ir) injection (5 mg/rat) caused erythrocytosis, arteriosclerosis, and abnormal plasma concentrations of asparagine, glycine, histidine, and lysine. Resection of the ipsilateral (Ni3S2-treated) kidney on the fourth day after the ir injection prevented erythrocytosis, amino acid disturbances, and severe arteriosclerotic lesions (fibrous intimal plaques and focal medial necrosis), but did not prevent early arteriosclerotic lesions (subintimal oedema with splitting of elastica). The early arteriosclerotic lesions appear to be initiated by vascular dissemination of Ni3S2 particles immediately post-injection, whereas the erythrocytosis, amino acid disturbances, and advanced arteriosclerotic lesions depend upon continued presence of the Ni3S2-injected kidney. Resection of the contralateral (non-injected) kidney has no effect upon Ni3S2-induced erythrocytosis, arteriosclerosis, or amino acid disturbances. Glomerulomegaly and mesangial hyperplasia developed in control rats following unilateral nephrectomy, owing to compensatory renal hypertrophy. Glomerulomegaly was more pronounced in Ni3S2-treated rats following contralateral nephrectomy than following ipsilateral nephrectomy, suggesting that erythrocytosis and compensatory renal hypertrophy act synergistically to enhance glomerulomegaly.