ALKYLATION DAMAGE AND REPAIR IN ALZHEIMERS-DISEASE LYMPHOCYTES

We have previously shown that lymphocytes from Alzheimer's disease (AD ) patients are hypersensitive to ionising radiation, as revealed by th eir higher levels of dicentrics than those from age-matched, normal in dividuals. We have now examined the sensitivity of these cells to N-me thyl-N-nitro-sourea or methyl methanesulphonate, using a variety of as says, namely unscheduled DNA synthesis, viability, sister chromatid ex change and, via high performance liquid chromatography, level of methy lation and repair of the adducts, 7-methylguanine, 0(6)-Methylguanine and 3-methyladenine. We have found that AD lymphocytes and age-matched normal lymphocytes respond similarly to methylation damage, as assess ed by all these techniques.