PHENOMENA OF ADAPTATION IN RATS CONTINUOUSLY EXPOSED TO LOW CONCENTRATIONS OF ACROLEIN

Abstract

After 11 to 21 days, rats continuously exposed to 0.55 ppm acrolein had significantly lower body weight, liver weight (relative to weight), and serum levels of acid phosphatases than the controls. The intoxicated rats also showed signs of irritation in the upper respiratory tract, a significant lowering of the number of alveolar macrophages and a higher susceptibility to airborne Salmonella enteritidis infection. The difference at the respiratory stage, between acrolein intoxicated animals and controls subsequently disappeared however, even though exposure was continued, so that, at the 63rd day of exposure, the two groups showed an identical susceptibility to airborne S. enteritidis infection. In the same way, the differences between the weight percentages of the liver and the levels of acid phosphatases, disappeared. A highly significant difference remained however between the body weights of the control and intoxicated rats. The adaptation phenomena seemed to become established after 3 to 4 weeks of exposure.