Quote Originally Posted by khoa
my 2 cents,

why doesn't that tar eventually give you cancer like cigarettes do? Well there's a nifty enzyme by the name of CYP1A1 that goes around activating these carcinogens. It's not the only one, but it's the primary one. Anyways, nicotine is known to activate this, but THC however, simply doesn't. This is probably where the lung cancer prevention argument comes from. This definitely isn't the only way, but it's a pathway that i've studied for half a semester this fall for a class. Causes asthma? Haha yeah, when THC dilates your bronchioles and helps you breathe better, that'll definitely cause asthma. I use to carry an inhaler around all the time and had it really really bad when i was in grade school. What's weird is that I've never touched one of those since high school, around the time i started smoking mj.
A+ Post Cytochrome P450? Activated by PAH's? Coolio!

http://www.ncbi.nlm.nih.gov/entrez/q...list_uids=1543