[Chronic exposure to arsenic in rats: morphological and functional findings]

Male Sprague-Dawley rats, who had received 50 micrograms/ml of arsenic (as sodium arsenate) in drinking water for 320 days, showed high urinary excretion of this element. Arsenic was accumulated in tissues, mostly in the kidney and in the liver. In the kidney were evident slight focal alterations in tubules and glameruli; some of the tubules contained casts of amorphous hyaline material. The hepatocytes close to the centrolobular veins were swollen and showed ultrastructural alterations. The seric GOT, GPT and LDH activities were normal, while the alkaline phosphatase alto have been found in the brain, sciatic nerve, lung, heart and arteries. No significant changes of systolic and diastolic blood pressure levels were observed. Similarly, cardiac inotropism and chronotropism were unchanged. The electrocardiogram, also, was normal. The cardiovascular reactivity to noradrenaline, acetylcholine, histamine, serotonin, bradykinin and angiotensin II was unchanged. However, the vascular reactivity to the beta-stimulation was increased, while it was decreased to the angiotensin I. On the whole, our results suggest that chronic arsenic exposure produces focal alterations in the kidney and characteristic modifications in the hepatic structure and in the cardiovascular reactivity.