Vol. 282, Issue 1, L67-L74, January 2002
Acute lung injury and lung transplantation influence in vitro
subtype conversion of pulmonary surfactant
Gayatri
Maitra1,
Kevin
Inchley1,
Richard J.
Novick2,
Ruud A. W.
Veldhuizen3,
James F.
Lewis3, and
Fred
Possmayer1
1 Medical Research Council Group in Fetal and Neonatal
Health and Development, Departments of Biochemistry and Obstetrics and
Gynaecology, University of Western Ontario, London N6A 5A5;
2 Transplant-Immunology Group, Robarts Research Institute, and
Division of Cardiovascular-Thoracic Surgery, London Health Sciences
Centre-University Campus, London N6A 5A5; and 3 Division of
Respiratory Medicine, Department of Physiology, and Lawson Health
Research Institute, St. Joseph's Health Centre, London, Ontario,
Canada N6A 4V2
The effects of
surfactant treatment on surfactant subtype conversion after lung injury
were examined. Dogs were subjected to hyperventilation for 8 h
with or without surfactant treatment. Lungs were stored for 17 h,
and the right lung was transplanted and reperfused for 6 h. Conversion
of large aggregate (LA) surfactant to small aggregates was investigated
using in vitro surface area cycling. LA from transplanted lungs
(Transplant-LA) from the nontreated group converted more rapidly than
Transplant-LA from the treated group. Transplant-LA from both groups
converted more rapidly than LA from normal lungs. Calculations based on
[3H]dipalmitoylphosphatidylcholine in the administered
surfactant [bovine lipid extract surfactant (BLES)] showed that the
endogenous component of Transplant-LA converted more rapidly than the
exogenous component. This indicates exogenous BLES did not equilibrate
completely with endogenous surfactant. LA from hyperventilated, stored
donor right lungs and from the recipients' native lungs from the
nontreated group converted more rapidly than corresponding LA in the
BLES-treated group. Similar relative conversions were observed with
exogenous components from all lungs. Relative conversion of endogenous
component from Transplant-LA was more rapid than that from LA from
donor's stored right lung or from the recipient's native right lung.
Low levels of phenylmethylsulfonyl fluoride inhibited conversion of Transplant-LA to a greater extent than normal LA. LA from all experimental groups had similar protein levels. These studies show
acute lung injury, transplant, ischemia-reperfusion, and surfactant treatment have major effects on surfactant subtype integrity.
carboxyesterase; convertase; dipalmitoylphosphatidylcholine; ischemia-reperfusion; surfactant subtype conversion
