Maintenance of brain monoamine oxidase B inhibition in smokers after overnight cigarette abstinence

Objective: The authors' goal was to replicate a previous finding that smoke rs have lower brain monoamine oxidase B (MAO-B) levels than comparison nons moking subjects and to determine if levels recover after overnight cigarett e abstinence. Method: Brain MAO-B levels were measured by means of positron emission tomo graphy in six smokers who were scanned twice: 11.3 hours (baseline) and 10 minutes after smoking one cigarette. Results: Average MAO-B levels in smokers in the present study were similar to those found in the previous study and averaged 39% (SD=17) lower than th ose found in a comparison group of nonsmokers. Brain MAO-B levels did not d iffer between baseline levels and 10 minutes after smoking. Conclusions: This study reinforces the need to investigate whether MAO-B in hibition may account for some of the behavioral and epidemiological feature s of smoking.