Elevation of plasma peptidoglycan and peripheral blood neutrophil activation during hemorrhagic shock: plasma peptidoglycan reflects bacterial translocation and may affect neutrophil activation.
OBJECTIVE
To investigate the relations among bacterial transloation, plasma peptidoglycan elevation, and peripheral blood neutrophil activation during hemorrhagic shock.


METHODS
Prospective, randomized, unblinded animal study.


METHODS
Surgical research laboratories of Shiga University of Medical Science.


METHODS
Male, specific pathogen-free Sprague-Dawley rats.


METHODS
The rats were randomly divided into three groups: a conventional group with normal intestinal flora (NF), an antibiotic (streptomycin and penicillin G) decontaminated group (AD), and a sham shock group with normal intestinal flora. The NF and AD groups were subjected to hemorrhagic shock (mean arterial pressure 30 mm Hg, for 30 to 90 mins). Rats were killed at 30, 60, and 90 mins after shock induction. Systemic blood and mesenteric lymph nodes (MLNs) were cultured for the determination of bacterial translocation (BT). Systemic plasma peptidoglycan and endotoxin concentrations were measured. To evaluate peripheral blood neutrophil activation, phagocytosis and hydrogen peroxide generation were assayed by flow cytometry.


RESULTS
In the NF group, BT to MLNs was significantly increased from 30 mins after shock induction. Blood culture and plasma endotoxin were positive at 90 mins but there were no significant differences. Assayed plasma peptidoglycan was significantly increased at 90 mins. Phagocytosis and hydrogen peroxide generation were significantly increased. Assayed plasma peptidoglycan concentrations showed significant positive correlations with the magnitude of BT to MLNs (r2 = .54) and hydrogen peroxide generation (r2 = .22) in individual animals. Furthermore, BT and these parameters were significantly suppressed in the AD group.


CONCLUSIONS
First, we concluded that assayed plasma peptidoglycan reflects BT induced by hemorrhage because the increase in assayed plasma peptidoglycan was suppressed, as was BT, by antibiotic decontamination. Second, peripheral blood neutrophil activation was also suppressed when BT was prevented. We concluded BT to be involved in neutrophil activation. Our findings suggest hydrogen peroxide generation by neutrophils to be involved in plasma peptidoglycan elevation.
Shimizu
Tomoharu
T
First Department of Surgery, Shiga University of Medical Science, Otsu-shi Shiga, Japan.
Tani
Tohru
T
Endo
Yoshihiro
Y
Hanasawa
Kazuyoshi
K
Tsuchiya
Masakazu
M
Kodama
Masashi
M
D000818:Animals; D018988:Bacterial Translocation / Q000502:physiology*; D004731:Endotoxins / Q000097:blood; D008297:Male; D018375:Neutrophil Activation / Q000502:physiology*; D010400:Penicillin G / Q000494:pharmacology; D010457:Peptidoglycan / Q000097:blood*; D010587:Phagocytosis; D011446:Prospective Studies; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D012771:Shock, Hemorrhagic / Q000097:blood* / Q000382:microbiology; D013047:Specific Pathogen-Free Organisms; D013307:Streptomycin / Q000494:pharmacology
D004731:Endotoxins; D010457:Peptidoglycan; D010400:Penicillin G; D013307:Streptomycin