title: Evaluation of effects of PAF on alveolar fluid clearance with use of NMR imaging.
abstract: Autologous serum with or without platelet-activating factor (PAF) was instilled into one lung lobe of an anesthetized cat, and changes in the regional lung water content were monitored for 4 h with proton nuclear magnetic resonance (NMR) images and relaxation time measurements. With serum as an instillate, water was cleared with a half time of approximately 670 min; after 4 h, 86 +/- 6% of that instilled remained. With PAF added to the instillate, clearance was biphasic with an initial clearance half time of approximately 30 min followed by clearance similar to that observed after serum instillation; after 4 h, 35 +/- 4% of that instilled remained. In contrast, 4 h after instillation of serum or serum plus PAF, 91 +/- 3% and 82 +/- 5%, respectively, of the instilled 125I-labeled albumin remained in the lung (P = 0.06). From transverse magnetization relaxation curves we were able to resolve two relaxation components, which we have attributed to the instilled fluid in the air spaces (relaxation time = 177 +/- 7 ms) and the tissue-bound fluid (relaxation time = 25 +/- 1 ms).
authors.affiliation: Department of Applied Sciences in Medicine, University of Alberta, Edmonton, Canada.
authors.forename: P W
authors.initials: PW
authors.lastname: Stroman
authors.forename: P S
authors.initials: PS
authors.lastname: Allen
authors.forename: D C
authors.initials: DC
authors.lastname: Lien
authors.forename: G
authors.initials: G
authors.lastname: Machin
authors.forename: S F
authors.initials: SF
authors.lastname: Man
mesh_terms: D000818:Animals; D002415:Cats; D005070:Evans Blue; D015633:Extravascular Lung Water / Q000187:drug effects / Q000378:metabolism*; D008168:Lung / Q000033:anatomy & histology; D008279:Magnetic Resonance Imaging; D008706:Methemoglobin / Q000031:analogs & derivatives / Q000378:metabolism; D010972:Platelet Activating Factor / Q000494:pharmacology*; D011650:Pulmonary Alveoli / Q000187:drug effects / Q000378:metabolism*; D012121:Respiration, Artificial; D012711:Serum Albumin, Radio-Iodinated
chemical_list: D010972:Platelet Activating Factor; D012711:Serum Albumin, Radio-Iodinated; C007169:cyanomethemoglobin; D005070:Evans Blue; D008706:Methemoglobin