Effect of glutamine on the total antioxidant system of rats subjected to renal ischemia and reperfusion

Abstract

PURPOSE: To evaluate the protective effects of glutamine administered before renal ischemia-reperfusion on plasma antioxidant protection, and lung and renal tissue injury. METHODS: 33 rats underwent right nephrectomy. On the eighth postoperative day, animals were randomized into three groups (n=11): glutamine, control and sham. Each group of animals received, by gavage, a particular diet for 7 days. On day 14 following nephrectomy, the animals were subjected to left renal ischemia-reperfusion. After this, blood samples were collected and the animals were killed. At necropsy the kidney and lung were removed for histology. RESULTS: The levels of total antioxidant capacity were higher in the glutamine group and control group compared with the sham group. The levels of glutathione peroxidase in both the sham and glutamine groups were higher when compared with the control group (p<0.05). The level of superoxide dismutase in the sham group was clearly higher than that in the glutamine and control groups. Histological examination showed no differences between the three groups. CONCLUSION: Prior intake of glutamine improves total antioxidant capacity and increases glutathione peroxidase levels in rats subjected to renal ischemia-reperfusion.

Dietary glutamine prevents the loss of intestinal barrier function and attenuates the increase in core body temperature induced by acute heat exposure

“…The beneficial effects of dietary Gln enrichment on gastrointestinal function have already been reported in rodents subjected to different stressful conditions that are not necessarily associated with hyperthermia, such as intestinal obstruction ( 12 , 30 ) and burns ( 9 ) . Under these experimental conditions, Gln exerts beneficial effects through several mechanisms, including intestinal tropism ( 57 ) , inhibition of apoptosis ( 7 ) , stimulation of the Th1 inflammatory response ( 8 ) , reinforcement of the immune system against bacteria and endotoxins ( 9 ) , preservation of glutathione ( 11 ) and increased expression of HSP ( 3 , 5 ) . In particular, HSP are involved in the most basic mechanisms of cellular protection against stressful conditions ( 58 ) .…”

“…Glutamine (Gln) is an amino acid with many important metabolic functions. It serves as a fuel for rapidly dividing cells (particularly lymphocytes and enterocytes) ( 1 , 2 ) , induces the expression of heat shock proteins (HSP) ( 3 – 6 ) , prevents apoptosis induced by injury ( 7 ) , has immunoregulatory functions ( 8 , 9 ) , and is a key precursor for the intestinal synthesis of glutathione, one of the major antioxidants in the body ( 3 , 10 , 11 ) . Although Gln is the most abundant amino acid in the bloodstream, under certain conditions of stress, such as trauma, sepsis, major surgery, bone marrow transplantation, and intense chemotherapy and radiotherapy, the physiological requirement for Gln may exceed the capacity for endogenous synthesis such that Gln becomes a conditionally essential amino acid ( 3 ) .…”

Antioxidants as Renoprotective Agents for Ischemia during Partial Nephrectomy

“…This could reflect mainly non-specific scavenging ROS [48]. Another study shows that the use of glutamine amino acid supplementation, a precursor of GPx, prior to renal I/R elevates this powerful endogenous antioxidant in rats, which again proved to be efficient as an endogenous scavenger that preserved renal function [52].…”