The effects of glutamine-enriched feeding on incisional healing in rats

Abstract

Glutamine (Gln), which is the most abundant free amino acid in the circulation, and also a primary fuel for rapidly dividing cells, was used to determine its effects on incisional healing. The effect of Gln-enriched feeding was investigated using tensile strength mea- surement, which reflects the quality and speed of regen- eration, and by the measurement of tissue hydroxypro- line level which correlate directly with the collagen content of wounds. Forty albino Wistar rats in four equal groups received a special diet 7 days prior to sur- gery and 7 days after surgery. On the 7th day of study a 5-cm dorsal midline skin incision was made and then closed by interrupted sutures. Group 1 received a nor- mal diet for all 14 days; group 2 received a Gln-en- riched diet 7 days prior to surgery and a normal diet 7 days after surgery; group 3 received a normal diet prior to surgery and a Gln-enriched diet after surgery; group 4 received a constant Gln-enriched diet. On the 7th postoperative day, tensile strength measurements and hydroxyproline level analyses were done. A preopera- tive Gln-enriched diet did not show any significant im- provement in the tensile strength and hydroxyproline levels on the 7th postoperative day, but a pre- and post- operative, and a postoperative Gln-enriched diet signifi- cantly improved the tensile strength and hydroxyproline levels when compared with the normal diet group (P<0.0001). These findings show that wound healing is better when Gln was added in the postoperative, or both pre- and postoperative periods, but not when only added in the preoperative period.