Necrotizing vasculitis in athymic rats with infarct kidney hypertension.

Infarct kidney hypertension was induced in congenital athymic nude rats and in their haired normal littermates. In both groups a significant and similar elevation of blood pressure was observed. The mesenteric vessels were studied histologically five, 12 and 20 days after operation. Necrotizing vasculitis with and without perivascular inflammatory reactions was found in mesenteric arteries and arterioles in six out of six athymic and in six out of 11 control rats. In sham operated athymic rats and in haired littermates neither hypertension nor vasculitis was observed. These observations indicate that the thymus play no role in the pathogenesis of acute hypertensive vascular disease.