Ghrelin and gastrointestinal wound healing. A new perspective for colorectal surgery

The effect of stromal vascular fraction and Platelet-Rich Plasma combination on basic Fibroblast Growth Factor serum level during anal trauma healing in a Wistar rat model

Introduction

Stromal Vascular Fraction (SVF) and Platelet-Rich Plasma (PRP) application play important roles in the healing process by increasing basic Fibroblast Growth Factor (bFGF) secretion. This research assesses the effect of combined SVF and PRP local injection on bFGF levels, using an anal trauma model in Wistar rats.

Method

Twenty-eight adult Wistar rats were divided into three groups. Groups A and B underwent modified surgical anal trauma and repair; Group A was treated with the SVF and PRP combination local injection, while Group B was treated with only normal saline. Subsequently, we examined bFGF levels in Groups A and B on days 1, 7, and 14. Group C consisted of healthy controls sacrificed on day 0 to obtain baseline data on bFGF levels.

Results

The bFGF levels were higher in Group A than in Group B on every experimental day. The Repeated Measures test shows a significant increase in bFGF levels on day 1 (p = 0.000), day 7 (p = 0.000), and day 14 (p = 0.000). This test also indicates that the local injection combination of SVF and PRP increased bFGF levels by 96.2% compared to the placebo group.

Conclusion

The combination of SVF and PRP can increase bFGF levels during anal trauma healing in the Wistar rat model. Basic FGF is an important factor throughout the anal trauma healing process.

•

The combination of SVFs and PRP is effective to increase the concentration of bFGF.

•

Administration of SVFS + PRP by injection was better at increasing the expression of bFGF than by placebo.

•

The combination of SVFs and PRP increases the level of bFGF in the healing process of anal trauma.

Ghrelin regulates sepsis‑induced rat acute gastric injury

Ghrelin, a peptide expressed in the gastric mucosa, has an essential role in sustaining the normal function of the digestive system. Sepsis is one of the primary causes of mortality in intensive care units and can lead to multiple organ dysfunction, especially in the gastrointestinal system. The aim of the present study was to explore the effect of ghrelin on gastric blood flow in a rat model of sepsis, as well as the effect of ghrelin on the expression of the apoptotic markers, B-cell lymphoma 2 (Bcl-2) and Bcl-2-associated X (Bax), in gastric tissues. The sepsis model was established using cecal ligation and puncture (CLP). The expression levels of apoptosis-related factors in gastric epithelial cell were determined by immunohistochemistry, reverse transcription quantitative-PCR and western blotting. Collectively, the present results suggested that ghrelin administration attenuated sepsis symptoms induced by CLP. Blood flow in the stomach greater curvature was significantly higher in the CLP-induced sepsis group rats (284.3±95.7 perfusion units) compared with the sham operation group (317.8±5.2 perfusion units; P<0.05), whereas there was no difference between the CLP group treated with ghrelin (377.8±99.0 perfusion units) and the sham rats. Ghrelin administration also reduced the secretion of pro-inflammatory cytokines compared with the CLP-induced sepsis group rats. In addition, CLP significantly reduced the expression of Bcl-2 and enhanced the expression of the pro-apoptotic proteins, Bax and cleaved caspase-3; whereas, ghrelin application reversed the effects of CLP on these apoptosis-associated proteins. In conclusion, the present study revealed that ghrelin has the ability to increase blood flow in the gastrointestinal tract in a sepsis model and can also regulate the expressions of apoptosis-associated factors in gastric tissues. These results suggest that ghrelin could be a novel treatment for sepsis-induced gastric injury.

Effects of Ghrelin on the Oxidative Stress and Healing of the Colonic Anastomosis in Rats

BACKGROUND

Anastomotic leakage is the deadliest complication of colonic procedures. Ghrelin is an orexigenic hormone with potent actions on growth hormone release and functions in the processes of growth, tissue inflammation, repair, and oxidative stress. We evaluated the hypothesis that the exogenous administration of ghrelin causes beneficial effects on the healing of colonic anastomosis.

MATERIALS AND METHODS

Sixty-four male Wistar rats were randomly assigned to eight subgroups receiving postoperative intraperitoneal administration of ghrelin (23 μg/kg/d) or saline after a colonic anastomosis. The anastomotic tissue was evaluated on the third, seventh, and 14th postoperative days. Anastomotic bursting pressure, histological parameters, hydroxyproline content, and tissue oxidative stress markers were compared.

RESULTS

There was a significant increase in the mean anastomotic bursting pressure in the ghrelin subgroup on the seventh postoperative day (P = 0.035). Histological evaluation demonstrated a significant difference in the neutrophilic infiltrate (P = 0.035) on the third and 14th d and in apoptosis (P = 0.004), granulation tissue (P = 0.011) and peritoneal inflammation (P = 0.014) on the 14th postoperative day. There was a statistically significant increase in the hydroxyproline content in the ghrelin subgroup on the 14th postoperative day (P = 0.043). There were significant differences in the nitrite tissue levels (P = 0.021) on day 3 and in reactive oxygen species (P = 0.012) on day 14.

CONCLUSIONS

The administration of ghrelin had beneficial anti-inflammatory and antioxidant effects, increasing the resistance of the anastomosis and the hydroxyproline tissue content in the postoperative period.