MACROPHAGES ARE A MAJOR SOURCE OF ACETALDEHYDE IN CIRCULATING ACETALDEHYDE ALBUMIN COMPLEXES FORMED AFTER EXPOSURE OF MICE TO ETHANOL

C57BL mice were depleted of macrophages by an intravenous injection of liposome encapsulated dichloromethylene diphosphonate (DCMDP), and co ntrol mice were uninjected or injected with empty liposomes. One day a fter injection, a proportion of the DCMDP-treated and control mice was continuously exposed to ethanol vapor for 4 days. Albumin fractions w ere separated from the sera of both ethanol-unexposed and ethanol expo sed animals and tested for cytotoxicity against a monolayer of A9 cell s using two indicators of cytotoxicity: detachment of adherent cells a nd a decrease in the ability of cells to reduce tetrazolium. The resul ts show that, in mice exposed to ethanol, macrophages are a major sour ce of the acetaldehyde in circulating cytotoxic acetaldehyde-albumin c omplexes and presumably also of free acetaldehyde.