The Effect of Low-, Medium- and High-Tar Cigarette Smoke on the Fate of Arachidonic Acid in Isolated Hamster Lungs

Abstract: Isolated hamster lungs were ventilated with smoke from low-, medium- and high-tar cigarettes when 45 nmol of ¹⁴C-arachidonic acid was infused into the pulmonary circulation. Most of the infused radioactivity was found in different phospholipid and neutral lipid fractions of the perfused lungs and a smaller amount was found in the nonrecirculating perfusion effluent mainly as metabolites. Cigarette smoke ventilation increased the amount of ¹⁴C-arachidonic acid in the triacylglycerols of the perfused lungs but had usually no effect on the amount of radioactivity in diacylglycerols or in different phospholipids. The increased amount of radiolabel in triacylglycerols was significantly greater in the lungs ventilated with smoke from medium- or high-tar cigarettes than in those ventilated with low-tar cigarette smoke. Cigarette smoke ventilation increased the amount of unmetabolized arachidonate in the perfusion effluent and decreased the amount of many metabolites. The present study indicates that low-, medium- and high-tar cigarettes have effects of the fate and metabolism of arachidonic acid in isolated hamster lungs and that the effects of medium- and high-tar cigarettes are more clear that those of low-tar cigarettes when the cigarettes are burned with a constant puff volume and rate.