Cytotoxic protein molecules generated as a consequence of ethanol metabolism in vitro and in vivo

A non-dialysable cytotoxic activity developed in the supernatants of human blood-monocyte-derived macrophages cultured in the presence of ethanol and in the serum of three healthy volunteers who drank 500-700 ml wine over 20-35 min. On 'Sephacryl S-300' gel filtration of the culture supernatants and the serum samples from the subjects who took alcohol, the cytotoxic activity eluted together with albumin molecules. Studies of human serum and of various commercially purchased human serum protein fractions treated with carbon-14-labelled acetaldehyde and non-radioactive acetaldehyde, respectively, provided strong circumstantial evidence that the cytotoxic proteins were albumin molecules that had become complexed with acetaldehyde generated by the metabolism of ethanol. The cytotoxic activity developing in vivo was greatest 6-10 h after the consumption of ethanol started, when blood alcohol levels were normal or only slightly high. The appearance of a circulating long-acting cytotoxic macromolecule after the ingestion of ethanol may be of considerable importance in clarifying the mechanisms underlying ethanol-induced tissue damage.