Insulin-like growth factor-I improves mucosal structure and function in transplanted rat small intestine

Area of Science:

• Gastroenterology and Transplant Surgery
• Endocrinology and Molecular Biology

Background:

• Small bowel transplantation often results in mucosal atrophy, impaired absorption, and bacterial translocation.
• Elemental diets or total parenteral nutrition exacerbate these post-transplant complications.

Purpose of the Study:

• To investigate the effects of insulin-like growth factor-I (IGF-I) on the mucosal structure and barrier function of rat small bowel isografts.
• To assess IGF-I's impact on nutrient absorption and bacterial translocation following small bowel transplantation.

Main Methods:

• Adult Lewis rats underwent either jejunal isograft transplantation or small bowel transection.
• Rats received a polymeric diet via gastrostomy and were infused with either IGF-I or a vehicle control.
• Measurements included crypt cell production, morphometrics, absorption, body weight, bacterial translocation, and gene expression (IGF-I, IGF-IR, IGFBP-3, IGFBP-4).

Main Results:

• IGF-I infusion significantly increased jejunal crypt cell production, villus height, crypt depth, and surface area in both transplanted and control rats.
• Glucose and water absorption were significantly improved in IGF-I treated groups.
• IGF-I administration reduced bacterial translocation to mesenteric lymph nodes and increased body weight.

Conclusions:

• Administration of IGF-I improves mucosal structure, enhances absorptive function, and reduces bacterial translocation in small bowel transplants.
• IGF-I demonstrates potential as both an endogenous and administered factor to support transplanted small bowel viability and function.