The impact of inhaled acrolein on hypertension-sensitive and resistant rats

The Dahl selected rat lines, one susceptible to salt-induced hypertension (DS) and the other resistant to salt-induced hypertension (DR), were subchronically exposed to filtered air, 0.4, 1.4, or 4.0 ppm acrolein. All of the DS rats exposed to 4.0 ppm acrolein died within the first 11 days, while 60% of the DR animals survived. Neither dose dependent blood pressure changes nor altered behavioral characteristics were evident following acrolein exposure. Exposure to 4.0 ppm acrolein increased the level of several serum enzymes. This concentration of acrolein also led to pulmonary edema and a significant increase in lung connective tissue. There was a marked difference in the pulmonary pathology observed in DS and DR rats exposed to 4.0 ppm acrolein. The lungs of the DS rats exhibited severe airway epithelial necrosis with edema and hemorrhage, while surviving DR rats primarily showed a proliferative change. Following exposure to 0.4 to 1.4 ppm acrolein, both rat lines displayed similar pathologic change. Epithelial hyperplasia and/or clusters of macrophages were usually found near terminal bronchiolar areas. These findings suggest that further investigation of the physiopathologic sensitivity of the DS rat line may elucidate a model for investigating the underlying characteristics of stress susceptible populations.