Decrease in the rat bronchial acetylcholinesterase activity after toluene diisocyanate inhalation.
Acetylcholinesterase (AChE) activity was measured in bronchial tissue homogenate and blood from rats subjected to single and repeated 4-h daily inhalation exposure to toluene diisocyanate (TDI) or control atmospheres. A single 4-h exposure to TDI in the concentration range of 0.7-4.3 ppm did not decrease AChE activity in bronchial tissue but a 4-h exposure to 0.6 ppm TDI, or greater, for two consecutive days did reduce this activity (19% to 33% of the controls). Increasing the level of exposure to TDI for two consecutive days from 0.6 to 4.0 ppm and extending the length of exposure to 1.2 ppm TDI from 2 to 4, 9 or 14 days produced no further decrease in bronchial ACHE activity. Throughout these experiments, blood AChE activity remained unchanged. In rats exposed to 0.3 or 1 ppm TDI for 3 weeks, staining of the bronchial smooth muscle for AChE was reduced (36% of the controls) after exposure to 1 ppm TDI. These results support, for the first time, in vivo and localized anti-AChE activity by TDI.
Brondeau
M T
MT
Institut National de Recherche et de Sécurité, Vandoeuvre, France.
Ban
M
M
Simon
P
P
Bonnet
P
P
de Ceaurriz
J
J
D000110:Acetylcholinesterase / Q000097:blood / Q000378:metabolism*; D000280:Administration, Inhalation; D000818:Animals; D001980:Bronchi / Q000187:drug effects / Q000201:enzymology* / Q000378:metabolism; D002800:Cholinesterase Inhibitors / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D006651:Histocytochemistry; D007274:Injections, Intraperitoneal; D008297:Male; D009130:Muscle, Smooth / Q000201:enzymology / Q000378:metabolism; D009388:Neostigmine / Q000008:administration & dosage / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D013997:Time Factors; D014051:Toluene 2,4-Diisocyanate / Q000008:administration & dosage / Q000494:pharmacology*
D002800:Cholinesterase Inhibitors; D014051:Toluene 2,4-Diisocyanate; D009388:Neostigmine; D000110:Acetylcholinesterase