“Since smoking exposes the entire body to the tobacco compounds that inhibit MAO B, we believed it had the potential to limit MAO B activity throughout the body – and the evidence backs our supposition,” said Joanna Fowler, one of the study’s authors.
Dr. Fowler and her colleagues in the Medical and Chemistry Department at Brookhaven National Laboratory in Upton, NY and the Psychiatry and Applied Mathematics Departments at the State University of New York in Stony Brook, NY developed a tracer method to determine whether smokers have reduced MAO B activity in their peripheral organs. Their findings were presented at the Society of Nuclear Medicine’s 50th Annual Meeting.
The study involved giving 7 smokers PET scans with the MAO B-specific binding radiotracers [11C]L-deprenyl and [11C]L-deprenyl-D2, with results compared to those from a group of 8 non-smokers. The study found that MAO B activity in the heart, lungs, kidneys, and spleen was significantly reduced in smokers relative to non-smokers. Reductions ranged from 33 to 46%. “The consequences of these reduced MAO-B levels,” declared Fowler, “need to be examined in greater detail, but at the very least it is clear that smokers’ peripheral organs are significantly impacted by their habit.”