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).
Conclusion: 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.