Pulmonary effects of the cocaine pyrolysis product, methylecgonidine, in guinea pigs.
The pulmonary effects of the cocaine pyrolysis product, methylecgonidine (MEG; anhydroecgonine methyl ester), were assessed in guinea pigs. Specific airway conductance (SGaw), which decreases during bronchoconstriction, was measured in guinea pigs exposed to atmospheres containing a condensation aerosol of MEG free base (13 +/- 1 mg/liter of air), nebulized MEG fumarate (3 and 12% in phosphate buffered saline) or nebulized acetylcholine chloride (0.2 and 0.4% in phosphate buffered saline). A decrease in SGaw to 24.0 +/- 4.2% (mean +/- 2 S.E.M.) of baseline levels was observed in guinea pigs breathing MEG free base. A decrease to 28.4 +/- 4.5% of baseline was observed following administration of 0.4% acetylcholine. No change in SGaw was measured in guinea pigs exposed to 3% MEG fumarate but SGaw was reduced to 69.3 +/- 5.3% of baseline after exposure to 12% MEG fumarate. MEG free base poses an alkaline challenge to the lung, 3% MEG fumarate is neutral (pH approximately 7.4) and 12% MEG fumarate is acidic (pH approximately 4.3); thus, MEG free-base and 12% MEG fumarate might provoke a reflex bronchoconstriction due to direct pulmonary irritant effects. These results suggest that MEG free base produced during crack pyrolysis may play a role in bronchoconstriction observed in crack smokers.
Chen
L C
LC
Nelson Institute of Environmental Medicine, New York University Medical Center, Tuxedo 10987.
Graefe
J F
JF
Shojaie
J
J
Willetts
J
J
Wood
R W
RW
D000818:Animals; D016084:Bronchoconstriction / Q000187:drug effects*; D003042:Cocaine / Q000031:analogs & derivatives* / Q000378:metabolism / Q000633:toxicity*; D006168:Guinea Pigs; D006358:Hot Temperature; D008297:Male
C068464:anhydroecgonine methyl ester; D003042:Cocaine