Table 6.5.

Cigarette smoking and Parkinson's disease: some possible biologic mechanisms

Nicotine

• Blocks nigral cell loss (hemitransection, MPTP)

• Increases growth factors

Cigarette smoke

• Reduces MAO‐B activity

• Gene–environment interaction of smoking and MAO‐B allele

• Complex mixture of combustion products – other actions?

MPTP, 1‐methyl‐4‐phenyl‐1,2,3,6‐tetrahydropyridine; MAO‐B, monoamine oxidase B.