Vol. 281, Issue 4, G957-G963, October 2001
Role of gut flora on intestinal group II
phospholipase A2 activity and intestinal injury in
shock
Ranna A.
Rozenfeld1,
Xueli
Liu1,
Isabelle
Deplaen1, and
Wei
Hsueh2
Departments of 1 Pediatrics and 2 Pathology,
Children's Memorial Hospital, Northwestern University Medical
School, Chicago, Illinois 60614
We previously showed
that group II phospholipase A2 (PLA2-II), a
secretory, bactericidal, and proinflammatory protein in intestinal crypts, is upregulated after lipopolysaccharide (LPS) and
platelet-activating factor (PAF) challenge. Here we examined whether
germ-free environment (GF) or antibiotic treatment (ABX) affects the
pathophysiological responses and intestinal PLA2-II
activity after PAF (1.5 µg/kg) or LPS (8 mg/kg) injection. We found
that LPS and PAF induced hypotension and mild intestinal injury in
conventionally fed (CN) rats; these changes were milder in ABX rats,
whereas GF rats showed no intestinal injury. PLA2-II enzyme
activity was detected in normal rat small intestine; the basal level
was not diminished in ABX or GF rats. PAF and LPS caused an increase in
PLA2-II activity, which was abrogated in GF and ABX rats.
Recolonization of GF rats by enteral contamination restituted their
PLA2-II response to PAF and LPS and susceptibility to bowel
injury. We conclude that PAF- and LPS-induced increases in
PLA2-II activity are dependent on gut bacteria, and ABX and
GF rats are less susceptible to LPS-induced injury than CN rats.
germ-free environment; mixed-antibiotic treatment; platelet-activating factor; lipopolysaccharide; bacteria
