Acrylonitrile inhalation in rats: I. Effect on intermediary metabolism.

In male Wistar rats the inhalation exposure to acrylonitrile (AN), 280 mg X m-3, 8 hours a day for five days significantly decreased the serum concentration of cholesterol and triglycerides, but the liver concentrations of phospholipids, and esterified fatty acids were unchanged. The liver microsomal protein and cytochrome P-450 content decreased significantly. On the other hand the levels of glucose, lactate and pyruvate in the blood and brain significantly increased up to 250% of controls. A microscopic examination of the lungs, liver, kidneys and adrenals did not show structural changes and the numbers and enzyme activities of alveolar macrophages were also unaffected. In single 12-hour inhalation exposures the elevation of blood glucose was proportional to the inhaled concentration of AN (average concentrations 57, 125, or 271 mg X m-3); the effect was significant at the lowest AN concentration and was intensified in the glucose tolerance test. The elevation of blood glucose proved to be the most sensitive and dose-related indicator of AN exposure of those observed.