Histological Evaluation of Insulin-like Growth Factor-I in Experimental Intestinal Ischemia–Reperfusion Injury: A Rat Study

Purpose: Intestinal ischemia–reperfusion injury (IRI) remains a major clinical challenge associated with substantial morbidity. Although the biological functions of insulin-like growth factor-I (IGF-I) have been extensively investigated, evidence regarding the direct administration of exogenous recombinant IGF-I in experimental intestinal IRI remains limited. This study evaluated the histological effects of recombinant IGF-I administered at different time points in a rat model of intestinal IRI. Methods: Male Wistar rats underwent 45 min of superior mesenteric artery occlusion followed by 3 h of reperfusion. Animals were allocated to five groups: Sham, untreated Control, and three IGF-I-treated groups receiving intraperitoneal recombinant IGF-I before ischemia, during ischemia, or at reperfusion. Histological injury was assessed using the Chiu grading system (0–5). Data were analyzed using non-parametric statistical methods. Results: Forty-five rats were included in the final analysis. Untreated controls demonstrated the greatest mucosal injury (median Chiu score: 4, IQR: 3–4), whereas Sham-operated animals exhibited minimal injury (median: 0, IQR: 0–1). All IGF-I-treated groups demonstrated lower median histological injury scores (median: 2), with the lowest median observed in the reperfusion group (IQR: 1–3). However, none of the individual comparisons with untreated controls remained statistically significant after Bonferroni correction. A post hoc exploratory pooled analysis demonstrated a similar histological pattern but likewise did not show a statistically significant difference between pooled IGF-I-treated animals and controls after adjustment for multiple comparisons. Conclusions: In this experimental rat model, exogenous recombinant IGF-I administration was consistently associated with lower histological injury scores than untreated ischemia–reperfusion controls, although a definitive treatment effect could not be established. These findings provide additional experimental evidence regarding the histological effects of recombinant IGF-I in intestinal ischemia–reperfusion injury and support further investigation in larger experimental studies incorporating quantitative histological, molecular, and functional endpoints.