Induction of heme oxygenase-1 improves impaired intestinal transit after burn injury.
BACKGROUND
Burn injury has been shown to impair intestinal transit. The induction of heme oxygenase (HO)-1, the rate-limiting enzyme in heme degradation, has been demonstrated to provide protection against various injuries. The aim of this study was to investigate whether the induction of HO-1 by hemin would improve impaired intestinal transit after burn injury.


METHODS
Burn/sham rats were divided into 3 groups: saline solution, hemin (HO-1 inducer), and hemin plus tin protoporphyrin IX. Intestinal transit was measured with the use of phenol red and assessed with the geometric center. The gene and/or protein expression of inducible nitric oxide synthase (iNOS), cyclooxygenase (COX)-2, interleukin (IL)-1beta, HO-1, and p38 mitogen-activated protein kinase (p38 MAPK) was measured by real-time polymerase chain reaction and/or by Western blot analysis.


RESULTS
Intestinal transit was delayed with burn injury and improved significantly with the induction of HO-1; burn injury significantly activated p38 MAPK and myeloperoxidase and increased gene and/or protein expression of iNOS, COX-2, IL-1beta, and HO-1. The administration of hemin led to a significant decrease in the activation of p38 MAPK and myeloperoxidase and the gene and/or protein expression of iNOS, COX-2, and IL-1beta.


CONCLUSIONS
The induction of HO-1 improves burn-induced delayed intestinal transit. The beneficial effect of hemin treatment could be linked, at least in part, to the down-regulation of iNOS, COX-2, and IL-1beta expression, which suggests that the induction of HO-1 may provide an effective therapeutic measure for gut dysmotility after burn injury.
Gan
Hua Tian
HT
Department of Geriatric Medicine, West China Hospital, Sichuan University, Sichuan, China.
Chen
J D Z
JD
D000818:Animals; D002056:Burns / Q000378:metabolism* / Q000601:surgery*; D051546:Cyclooxygenase 2 / Q000235:genetics / Q000378:metabolism; D004790:Enzyme Induction / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005769:Gastrointestinal Motility / Q000187:drug effects* / Q000502:physiology; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D006419:Heme Oxygenase (Decyclizing) / Q000235:genetics* / Q000378:metabolism; D006427:Hemin / Q000494:pharmacology*; D053583:Interleukin-1beta / Q000378:metabolism; D007422:Intestines / Q000187:drug effects / Q000201:enzymology; D008297:Male; D008665:Metalloporphyrins / Q000494:pharmacology; D052247:Nitric Oxide Synthase Type II / Q000235:genetics / Q000378:metabolism; D009195:Peroxidase / Q000378:metabolism; D011183:Postoperative Complications / Q000188:drug therapy* / Q000378:metabolism; D011524:Protoporphyrins / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D020133:Reverse Transcriptase Polymerase Chain Reaction; D048051:p38 Mitogen-Activated Protein Kinases / Q000235:genetics / Q000378:metabolism
D004791:Enzyme Inhibitors; D053583:Interleukin-1beta; D008665:Metalloporphyrins; D011524:Protoporphyrins; D006427:Hemin; C032628:tin protoporphyrin IX; D009195:Peroxidase; D052247:Nitric Oxide Synthase Type II; C496318:Nos2 protein, rat; D006419:Heme Oxygenase (Decyclizing); C491523:Hmox1 protein, rat; D051546:Cyclooxygenase 2; D048051:p38 Mitogen-Activated Protein Kinases