[Role of hydrogen sulfide on expression of phosphatidylinositol 3 kinase/protein kinase B signal pathway in rats with intestinal ischemia/reperfusion injury]

Abstract

Objective: To explore the effect of hydrogen sulfide (H₂S) on expression of phosphatidylinositol 3 kinase/protein kinase B (PI3K/Akt) signal pathway in rats with intestinal ischemia/reperfusion (IRI) injury.

Methods: Thirty male Wistar rats were divided into sham operation group (Sham group), IRI group, and H₂S precursor sodium hydrosuphide (NaHS) intervention group (IRI+NaHS group) by random number table method, with 10 rats in each group. The animal model of IRI was established by 60 minutes superior mesenteric artery (SMA) blockage with non-invasive vascular clamp and 120 minutes reflow. SMA was dissociated and peritoneum cavity was closed in Sham group. The rats in IRI+NaHS group was received NaHS (100 μmol/kg bolus+1.07 mmol×kg^-1×h^-1 infusion) 10 minutes prior to the onset of reperfusion, while the rats in IRI group and Sham group were received equal volume of normal sodium. Blood in vena cava was collected. H₂S was detected by sensitive sulfide electrode. Rats were sacrificed after blood collection. Histopathology change was observed by hematoxylin-eosin (HE) staining, ileal pathological score was studied by Chiu score. The protein expressions of phosphated Akt (p-Akt), Akt, PI3K, cleaved caspase-9, mammalian target of rapamycin (mTOR) were determined by Western Blot.

Results: Compared with the Sham group, there was intestinal mucosa structure disorder edema and shedding villous fracture in the IRI group. Ileal pathological score in IRI group was significantly increased (4.21±0.15 vs. 0.15±0.03, P < 0.01), while plasma H₂S in IRI group was significantly decreased (μmol/L: 26.72±3.17 vs. 38.34±5.24, P < 0.01). Ileal p-Akt, PI3K, caspase-9 and mTOR protein in IRI group were significantly increased (p-Akt/GAPDH: 2.67±0.12 vs. 0.24±0.05, PI3K/GAPDH: 1.42±0.07 vs. 0.57±0.08, caspase-9/GAPDH: 4.23±0.61 vs. 0.13±0.02, mTOR/GAPDH: 2.17±0.23 vs. 0.23±0.02, all P < 0.01). Compared with the IRI group, pathological changes of intestinal mucosa in the IRI+NaHS group was improved, ileal pathological score was significantly decreased (1.56±0.02 vs. 4.21±0.15, P < 0.01), plasma H₂S was significantly increased (μmol/L: 32.36±2.45 vs. 26.72±3.17, P < 0.01) and ileal p-Akt, PI3K were significantly increased (p-Akt/GAPDH: 5.12±0.08 vs. 2.67±0.12, PI3K/GAPDH: 3.14±0.05 vs. 1.42±0.07, both P < 0.01), while caspase-9, mTOR in IRI+NaHS group were significantly decreased (caspase-9/GAPDH: 2.12±0.24 vs. 4.23±0.61, mTOR/GAPDH: 1.37±0.28 vs. 2.17±0.23, both P < 0.01).

Conclusions: H₂S attenuates intestinal injury in IRI rats by up-regulating PI3K/Akt signal pathway and down-regulating caspase-9 and mTOR.