Bronchial and alveolar absorption of inhaled 99mTc-DTPA

Journal Article · Sat Nov 01 04:00:00 EST 1986 · Am. Rev. Respir. Dis.; (United States)

DOI:https://doi.org/10.1164/arrd.1986.134.5.944· OSTI ID:7133377

Oberdoerster, G U; Utell, M J; Morrow, P E; Hyde, R W; Weber, D A

The clearance rate of 99mTc-DTPA deposited in the lung by inhalation has been used as an index to measure lung epithelial permeability. To determine if differences exist between alveolar and bronchial absorption of 99mTc-DTPA we measured regional clearance rates in 4 beagle dogs for 30 min after preferential bronchial and alveolar deposition. Alveolar deposition was maximized by inhalation for 2 min of small 99mTc-DTPA particles (activity median aerodynamic diameter, AMAD = 0.5 micron; geometric standard deviation, GSD = 1.6) with deep slow ventilation (VT = 350 ml; f = 9 min-1), and bronchial deposition was increased by inhalation of large particles (AMAD = 4.1 microns, GSD = 2.3) with rapid shallow ventilation (VT = 50 ml; f = 65 min-1). Respective clearance rates from basal regions, which represent mainly alveolar absorption, were: for small particles, 2.29% min-1; for large particles, 1.57% min-1 (p = 0.10). Apical regions, which contain relatively more bronchial surface than do the basal regions, showed the following clearance rates: for small particles, 1.76% min-1; for large particles, 1.31% min-1 (p less than 0.05). These results indicate that in vivo alveolar absorption of 99mTc-DTPA is more rapid than bronchial absorption. Control or verification of the site of deposition of the tracer in the lung is of importance for the interpretation of the results of the 99mTc-DTPA lung permeability assay.

• Research Organization: Univ. of Rochester, NY
• OSTI ID: 7133377
• Journal Information: Am. Rev. Respir. Dis.; (United States), Journal Name: Am. Rev. Respir. Dis.; (United States) Vol. 5; ISSN ARDSB
• Country of Publication: United States
• Language: English

Related Subjects

551001* -- Physiological Systems-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
AEROSOLS
AMINO ACIDS
ANIMAL TISSUES
ANIMALS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BODY
BRONCHI
CARBOXYLIC ACIDS
CHELATING AGENTS
CLEARANCE
COLLOIDS
DISPERSIONS
DOGS
DRUGS
DTPA
EPITHELIUM
EXCRETION
HOURS LIVING RADIOISOTOPES
INHALATION
INTAKE
INTERMEDIATE MASS NUCLEI
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
LUNG CLEARANCE
MAMMALS
NUCLEI
ODD-EVEN NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
PARTICLE SIZE
PERMEABILITY
RADIOISOTOPES
RADIOPROTECTIVE SUBSTANCES
RESPIRATORY SYSTEM
SIZE
SOLS
TECHNETIUM 99
TECHNETIUM ISOTOPES
TISSUES
UPTAKE
VERTEBRATES
YEARS LIVING RADIOISOTOPES