Metabolic effects of isoflurane on rat lungs perfused in situ.
1. The current experiments studied the effects of the inhalation anesthetic, isoflurane, on 5-hydroxytryptamine (5-HT) metabolism, protein synthesis, and angiotensin-converting enzyme activity in perfused rat lungs. 2. Under first order reaction conditions, isoflurane decreased the accumulation of tissue 5-hydroxyindoleacetic acid, the principle metabolite of 5-HT in a concentration-related, competitive, and reversible manner, indicating inhibition of endothelial 5-HT uptake. 3. In apparent contrast, isoflurane appeared to stimulate uptake of 5-HT by an imipramine-sensitive process, into a cell type unable to metabolize the parent amine. 4. Isoflurane increased absolute angiotensin-converting enzyme activity only at an inspired concentration of 5%. The anesthetic did not affect lung protein synthesis.
Martin
D C
DC
Department of Anesthesiology, Medical College of Georgia, Augusta 30912.
Carr
A M
AM
Watkins
C A
CA
D000818:Animals; D006246:Harmaline / Q000494:pharmacology; D007099:Imipramine / Q000494:pharmacology; D007530:Isoflurane / Q000494:pharmacology*; D007700:Kinetics; D008168:Lung / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D008297:Male; D009929:Organ Size / Q000187:drug effects; D007703:Peptidyl-Dipeptidase A / Q000378:metabolism; D010477:Perfusion; D010649:Phenylalanine / Q000378:metabolism; D014176:Protein Biosynthesis; D051381:Rats; D011919:Rats, Inbred Strains; D012701:Serotonin / Q000378:metabolism
D012701:Serotonin; D010649:Phenylalanine; D006246:Harmaline; D007530:Isoflurane; D007703:Peptidyl-Dipeptidase A; D007099:Imipramine