Hepatocyte apoptosis in rats exposed to benzo(a)pyrene

We studied the effect of benzo(a)pyrene on activity of nuclear endonucleases and expression of molecular regulator of apoptosis Bcl-2 in liver cells in rats. Intraperitoneal injection of benzo(a)pyrene (in a total dose of 60 mg/kg body weight) reduced activity of nuclear endonucleases in the liver cells, which attests to inhibition of apoptosis by the nuclear pathway. Injection of the toxicant enhanced the expression of intracellular molecular regulator of apoptosis Bcl-2 protein in the liver cells, which attested to triggering of proapoptotic signaling in these cells and organism's attempts to limit the development of apoptosis by the mitochondrial mechanism via activation of Bcl-2-dependent anti-apoptotic defense.