Similar level of metabolic activation of benzo(a)pyrene in perfused rat lung and liver and protection of lung by liver in a combined perfusion system

Abstract Irreversible binding of metabolically activated benzo(a)pyrene to DNA, RNA and protein proceeds by a different time course in perfused liver and lung of 5,6-benzoflavone-treated rats. Peak binding in liver is obtained after 15 min while binding in lung continuously increases over 120 min. Total irreversible binding per mg DNA or RNA is in the same order of magnitude in both organs. While binding in lung is lower at 15 min it exceeds binding in liver at 120 min. Binding per mg protein is higher in lung than in liver over the whole perfusion period. Introduction of a liver into the lung perfusion circuit decreases binding in lung. This protection effect is more pronounced when the li…