Effect of benz(a)pyrene and constant light exposure on rat liver lysosomes and biliary excretion of lysosomal enzymes.

Threefold administration of benz(a)pyrene in a dose of 20 mg/kg markedly stimulated biliary excretion of lysosomal enzymes from rat liver without signs of lysosomal damage. Constant light exposure induced changes attesting to functional activation of the lysosomal apparatus in liver cells and inhibited constitutive biliary excretion of lysosomal enzymes. Combined treatment decreased, but not abolished the stimulatory effect of benz(a)pyrene on vesicular transport of lysosomal enzymes to the bile.