title: Trichlorethylene and halothane inhibit uptake of 5-hydroxytryptamine in the isolated perfused rat lung.
abstract: Lung uptake of 5-hydroxytryptamine (5-HT) was determined in isolated perfused and ventilated rat lung, and was found to decrease with time according to a two-compartmental model. When the lungs were exposed to either trichlorethylene (TRI) or halothane, the uptake of 5-HT was drastically reduced. Both TRI and halothane gave log dose inhibition curves, which were superimposed, i.e. they were equally potent to inhibit lung uptake of 5-HT. At a concentration TRI of 18,000 ppm, the extraction of 5-HT was inhibited by 80 +/- 2 (X +/- S.E.M.) per cent, at 8500 ppm the inhibition was 65 +/- 6 per cent and 25 +/- 1 per cent at 3000 ppm. When the lungs were exposed to halothane, the inhibition was 85 +/- 6 per cent at 40,000 ppm, 48 +/- 1 per cent at 6000 ppm, and 15 +/- 0.3 per cent at 2000 ppm. When exposure to the solvent was discontinued, extraction of 5-HT was rapidly normalized. There was no detectable displacement of [3H]-5-HT from lungs saturated with the amine when they subsequently were exposed to solvent-containing atmosphere. This inhibition of lung uptake of 5-HT from the circulation is therefore postulated as to be an effect dependent on concentration solvent in the tissue, and is probably due to a reversible membrane stabilization of the endothelium.
mesh_terms: D000818:Animals; D001693:Biological Transport, Active / Q000187:drug effects; D000242:Cyclic AMP / Q000378:metabolism; D005260:Female; D006221:Halothane / Q000633:toxicity*; D066298:In Vitro Techniques; D008168:Lung / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D010477:Perfusion; D051381:Rats; D011919:Rats, Inbred Strains; D012701:Serotonin / Q000378:metabolism*; D014241:Trichloroethylene / Q000633:toxicity*
chemical_list: D014241:Trichloroethylene; D012701:Serotonin; D000242:Cyclic AMP; D006221:Halothane