AGE-RELATED-CHANGES ON MAO IN BL C57 MOUSE-TISSUES - A QUANTITATIVE AUTORADIOGRAPHIC STUDY/

The distribution of MAO-A and -B in brain and peripheral tissues of B1 /C57 mice and their changes during ageing were studied by quantitative enzyme radioautography with [H-3]Ro41-1049 and [3(H)]Ro19-6327. In th e brain, MAO-A decreased between weeks 4 and 8 and then remained uncha nged until 25 months, whereas MAO-B increased for the whole period stu died. Heart also showed a continuous increase in MAO-B, but not MAO-A, with ageing, and liver showed a decrease in MAO-B in the older animal s. These results show marked species differences in the distribution a nd age-related changes of MAO and might help to elucidate the high sen sitivity of B1/C57 mouse of MPTP, which increases with age.