Clearance of [sup 99m]Tc-labeled albumin from lungs in anesthetized guinea pigs

Journal Article · · Experimental Lung Research; (United States)

OSTI ID:6774546

Connelly, J C; Peterson, B T ^[1]

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1. Univ. of Texas Health Center, Tyler (United States)

Gamma imaging was used to measure the rate of clearance of aerosolized [sup 99m]Tc-human serum albumin (HSA) from the lungs of control guinea pigs and guinea pigs that received increased lung inflation or lung injury. Anesthetized guinea pigs were ventilated for 6 min with an aerosol of HSA and the radioactivity in the chest was monitored for 2 h with a gamma camera to determine whether the clearance rate would be a reliable assessment of lung epithelial permeability. Increased lung volumes were effected by application of 5 or 7 cm H[sub 2]O positive end-expired pressure (5-PEEP and 7-PEEP, respectively). Lung injury was induced either by intravenous oleic acid (OA, 27-73 [mu]l/kg) or inhalation of nitrogen dioxide (NO[sub 2], 80-100 ppm) for 2 h. Postmortem extravascular lung water volume (EVLW) provided an assessment of the degree of lung injury. Tracer clearance rates in animals receiving 5 or 7 cm H[sub 2]O PEEP were not significantly different from controls (K = 0.15 [+-] 0.05 and 0.24 [+-] 0.10 vs 0.12 [+-] 0.03%/min, respectively, p > .05). Animals exposed to NO[sub 2] had faster tracer clearance rates (K = 0.33 [+-] 0.21%/min, p < .05) and higher EVLW (5.8 [+-] 3.0 vs 3.7 [+-] 0.2 mL/g dry lung, p < .05) than controls. Clearance rates of HSA from the lungs of NO[sub 2]-exposed guinea pigs correlated well with injury as assessed by EVLW (r = .93, p < .01). Clearance rates of HSA and EVLW in animals receiving oleic acid were significantly higher than controls and the group receiving 5 cm H[sub 2]O PEEP (K = 0.58 [+-] 0.41%/min, EVLW = 8.1 [+-] 0.8 mL/g dry lung tissue, p < .05), but there was no correlation between these parameters in this injury model. It is concluded that imaging of the disappearance of radiolabeled HSA in the guinea pig can be a useful index of lung epithelial permeability, but this technique is limited to certain models of lung injury. 33 refs.

• OSTI ID: 6774546
• Journal Information: Experimental Lung Research; (United States), Journal Name: Experimental Lung Research; (United States) Vol. 19:2; ISSN EXLRDA; ISSN 0190-2148
• Country of Publication: United States
• Language: English

Related Subjects

550601* -- Medicine-- Unsealed Radionuclides in Diagnostics
62 RADIOLOGY AND NUCLEAR MEDICINE
ALBUMINS
ANIMAL TISSUES
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOLOGICAL EFFECTS
BODY
CARBOXYLIC ACIDS
CHALCOGENIDES
CLEARANCE
EPITHELIUM
EXCRETION
GAMMA RADIOGRAPHY
HOURS LIVING RADIOISOTOPES
INDUSTRIAL RADIOGRAPHY
INJURIES
INTERMEDIATE MASS NUCLEI
INTERNAL CONVERSION RADIOISOTOPES
ISOMERIC TRANSITION ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
LUNG CLEARANCE
LUNGS
MONOCARBOXYLIC ACIDS
NITROGEN COMPOUNDS
NITROGEN DIOXIDE
NITROGEN OXIDES
NUCLEI
ODD-EVEN NUCLEI
OLEIC ACID
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANS
OXIDES
OXYGEN COMPOUNDS
PERMEABILITY
PROTEINS
RADIOISOTOPES
RESPIRATORY SYSTEM
TECHNETIUM 99
TECHNETIUM ISOTOPES
TISSUES
TRACER TECHNIQUES
YEARS LIVING RADIOI