Sequential Changes on Arteritis in Rat Treated With Both X-Irradiation and Sodium Chloride

Five-week-old male Crj: CD (SD) rats were treated with 10% sodium chloride after a total dose of 20 Gy of X-ray administered to the gastric region in two equal fractions separated by 3 days. After treatments, the animals were sacrificed seqentially and analyzed quantitatively on the medial and small arteries in the stomach. In the early phase after X-irradiation, fibrous thickening of the intima was observed in the medium-sized arteries. Slight fibrosis of the adventitia appeared in the late phase after X-irradiation. The small artery with the fibrinoid necrosis of the serosa in the glandular stomach was recognized at 9 weeks after treatment with X-ray plus NaCl. These lesions were expanded into the small artery of the muscular layer, the submucosal and the mucosal layers, and the medium artery of the serosa. In quantitative analysis of the arteries using an image analyser, thickness of the arterial wall and the diameter of arteries became enlarged progressively in rats treated with X-ray plus NaCl.