Effects of bombesin on gut mucosal immunity in rats after thermal injury.
OBJECTIVE
Severe burns induce a disruption in gastrointestinal mucosal integrity and facilitate bacterial translocation (BT). Bombesin (BBS), a tetradecapeptide analogous to mammalian gastrin-releasing peptide, can induce the release of all gut hormones except secretin. This study examined the effects of BBS on mucosal immunity in rats after thermal injury.


METHODS
Forty-two Sprague-Dawley rats were divided into one sham control group and six burn groups. Burn groups were subjected to 35% total body surface area burn injury. One to 6 days after the injury, six animals (one from each group) were killed every 24 hours. Biliary secretory immunoglobulin A (SIgA), jejunal mucosal height, intestinal permeability, and BT to the mesenteric lymph nodes (MLNs), liver, and spleen were examined. In a second experiment, three groups of rats (6 in each) received either sham treatment and saline injection, or thermal injury and saline injection, or thermal injury and BBS injection. Twenty-four hours after burns or sham treatment, six animals (1 from each group) were killed. The biliary SIgA, jejunal mucosal height, and BT to the MLNs, liver, and spleen were examined.


RESULTS
The biliary SIgA decreased to one-seventh of normal levels 1 day after burn injury, and increased thereafter. The jejunal mucosal height decreased significantly to two-thirds of the normal value 1 day after burn injury. The intestinal mucosal permeability increased significantly to three times the normal level 2 days after the burn injury, and decreased thereafter. BBA significantly reduced the BT incidence and significantly increased the biliary SIgA and jejunal mucosal height 1 day after burn injury.


CONCLUSIONS
The results of this study show that, in rats, the intestinal permeability increased, the gut mucosal barrier failed, and the gut immunity deteriorated in the first few days after burn injury. BBS therapy helped to restore the postburn gut mucosal barrier in rats, by increasing biliary SIgA levels and the jejunal mucosal height.
Department of Surgery, Veterans General Hospital-Kaohsiung, Taiwan.
L W
LW
Chen
C M
CM
Hsu
J K
JK
Huang
J S
JS
Chen
S C
SC
Chen
D000818:Animals; D018988:Bacterial Translocation / Q000187:drug effects; D001839:Bombesin / Q000494:pharmacology*; D002056:Burns / Q000276:immunology*; D018928:Immunity, Mucosal / Q000187:drug effects; D007071:Immunoglobulin A, Secretory / Q000032:analysis; D007413:Intestinal Mucosa / Q000187:drug effects* / Q000276:immunology; D051381:Rats; D017207:Rats, Sprague-Dawley
D007071:Immunoglobulin A, Secretory; D001839:Bombesin