[Studies of the possible mechanisms for protective effects of recombinant human growth hormone on intestinal mucosa barrier in rat sepsis].
OBJECTIVE
To investigate the protective effects of recombinant human growth hormone (rhGH) on intestinal mucosal barrier in rat sepsis and explore its possible mechanisms.


METHODS
E. coli was injected intraperitoneally to produce rats sepsis models. Forty-two female SD rats were randomly divided into the control group (group C), sepsis group (group S) and treatment group (group T). Group S and group T were further divided into 1 d and 3 d subgroups (T1d,T3d, Sld, S3d), respectively. The expression of IGF-1 mRNA in liver, expression of Bcl-2 protein in intestine, bacteria translocation, the levels of growth hormone(GH) and insulin-like growth factor-1 (IGF-1) in plasma, and the histological appearance of intestine were determined dynamically by means of RT-PCR, radioimmunoassay, immunohistochemical staining and other corresponding methods, respectively.


RESULTS
(1) rhGH could significantly attenuate intestinal mucosal injuries and ameliorate bacteria translocation on sepsis rats. (2) The levels of Bcl-2 protein expression in intestine in group T (T1d:2441 +/- 117; T3d: 3628 +/- 235) were obviously higher than those of group S (S1d: 321 +/- 36; S3d: 1873 +/- 57) (P < 0.01). (3) The plasma levels of GH in group T (T1d: 1.28 +/- 0.24 microg/L; T3d: 2.14 +/- 0.48 microg/L) increased markedly than those of group S (S1d: 0.74 -/+ 0.12 microg/L; S3d: 0.60 +/- 0.18 microg/L) (P < 0.01). (4) The plasma levels of IGF-1 in group T (Tld: 168.94 +/- 65.67 microg/L; T3d: 201.56 +/- 64.98 microg/L) elevated significantly than those of group S (Sld: 116.72 +/- 13.96 microg/L; S3d:107.50 +/- 23.53 microg/L) (P < 0.05). (5) The levels of liver IGF-1 mRNA in group T (Tld: 0.98 +/- 0.20; T3d: 1.76 +/- 0.17) were significantly higher than those in group S (S1d: 0.38 +/- 0.09; S3d: 0.46 +/- 0.10) (P < 0.01).


CONCLUSIONS
rhGH conferred protective efficacy in maintaining the integrity of intestinal mucosal barrier against sepsis in rat. The possible mechanisms might involve the rhGH-diminished apoptosis of intestinal mucosa cells and the rhGH-maintained intestinal mucosa barrier via the roles of GH and IGF-1.
Department of Pathophysiology, West China School of Preclinical and Forensic Medicine, Sichuan University, Chengdu 610041, China.
Ying
Y
Huang
Cheng
C
Yi
Yang
Y
Long
Qiu-ling
QL
Zhao
Cong-xun
CX
Jiang
Yong-xia
YX
Cui
Rong-hua
RH
He
Shu-ren
SR
Wang
D000818:Animals; D018988:Bacterial Translocation / Q000187:drug effects; D004927:Escherichia coli Infections / Q000188:drug therapy*; D005260:Female; D019382:Human Growth Hormone / Q000097:blood / Q000235:genetics / Q000627:therapeutic use*; D006801:Humans; D007150:Immunohistochemistry; D007334:Insulin-Like Growth Factor I / Q000032:analysis / Q000096:biosynthesis / Q000235:genetics; D007413:Intestinal Mucosa / Q000187:drug effects* / Q000378:metabolism / Q000382:microbiology; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D011863:Radioimmunoassay; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D011994:Recombinant Proteins / Q000627:therapeutic use; D020133:Reverse Transcriptase Polymerase Chain Reaction; D018805:Sepsis / Q000188:drug therapy*; D051028:bcl-2-Associated X Protein / Q000096:biosynthesis / Q000235:genetics
D012333:RNA, Messenger; D011994:Recombinant Proteins; D051028:bcl-2-Associated X Protein; D019382:Human Growth Hormone; D007334:Insulin-Like Growth Factor I