Smoking is a very fast method of absorption due to the base environment of the lungs (basic environment is faster absorption than acidic environment when the drug is basic, like cigarette smoke). Wouldn't inhaling vapor still enter the lungs in order to get into the bloodstream? When you say MAOIs do you mean the drugs that inhibit mono amine oxidase? MAO is an enzyme that clears a synaptic channel, not a chemical produced in smoke. I'm just wondering how vapor could differ from smoke in absorption, having studied the subject quite extensively...
36mg of nicotine, if ingested, would put an average human in the hospital. Rarely does a cigarette exceed 2mg. Generally, they average a tad bit over 1 mg each. One would feel very ill if they consumed 36 cigarettes at the exact same moment...
EDIT: Were you referring to the article that found lower MAO A and MAO B in rats from cigarette chemicals other than nicotine alone? If so, I got you now. The chemicals other than nicotine act as MAOIs. That is interesting. The nasty "other chemicals" would then contribute to increased pleasure, and thus be more addictive. That is terrible, but interesting.