Lead nitrate-induced proliferation and death (apoptosis) in liver, kidney, and spleen of rats

Abstract

Among the many circumstances in which apoptosis plays a role, there is the reduction of cell number during regression of organ hyperplasia due to mitogens. The present study investigates whether a single intravenous injection of lead nitrate to rat could exert a proliferative stimulus in a number of organs (i.e., liver, kidney, spleen, intestine, stomach, brain, and heart), and, as well, looks at the fate of the cells generated by the mitogenic stimulus. Microscopic analysis revealed that liver, spleen, and kidney are affected by metal intoxication, while intestine, stomach, brain, and heart are partially or totally resistent to the treatment. Proliferation of the hepatic, renal, and splenic tissues was observed within a few days of treatment, followed by regression of hyperplasia due to apoptosis. The appearance of apoptotic cells was never observed during proliferation or at restoration of the organ mass. In the tissue sections, apoptotic cells were observed both in the extracellular spaces and inside the cytoplasm of the healthy ones, as a result of their phagocytosis