Insulin Attenuates the Systemic Inflammatory Response in Endotoxemic Rats

• Published in: Endocrinology (Philadelphia) 2004-09, Vol.145 (9), p.4084-4093
• Main Authors: Jeschke, Marc G, Klein, Dagmar, Bolder, Ulrich, Einspanier, Ralf
• Format: Article
• Language: English
• Subjects: Animals; Biological and medical sciences; Blood Glucose - metabolism; CCAAT/enhancer-binding protein; Cell activation; Cell survival; Chemokine CCL5 - genetics; Cytokines; Cytokines - genetics; DNA-Binding Proteins - genetics; Electrolyte metabolism; Electrolytes; Electrolytes - blood; Endotoxemia; Endotoxemia - drug therapy; Endotoxemia - immunology; Fundamental and applied biological sciences. Psychology; Gene expression; Glucose; Glucose metabolism; Hepatocytes; High mobility group proteins; Hypoglycemic Agents - pharmacology; Inflammation; Inflammatory response; Insulin; Insulin - pharmacology; Interleukins; Liver; Liver - physiology; Lymphocytes; Lymphocytes T; Macrophages; Male; Proteins; RANTES; Rats; Rats, Sprague-Dawley; Repressor Proteins - genetics; RNA, Messenger - analysis; Sepsis; Serum levels; Signal Transduction - immunology; STAT3 Transcription Factor; Suppressor of Cytokine Signaling 3 Protein; Suppressor of Cytokine Signaling Proteins; Trans-Activators - genetics; Transcription activation; Transcription factors; Transcription Factors - genetics; Vertebrates: endocrinology
• ISSN: 0013-7227; 1945-7170
• DOI: 10.1210/en.2004-0592

Insulin decreases the mortality and prevents the incidence of infection and sepsis in critically ill patients. The molecular and cellular mechanisms by which insulin improves survival have not been defined. The purpose of the present study was to determine the effect of insulin on the inflammatory reaction during endotoxemia. Endotoxemic rats were randomly divided into two groups to receive either saline or insulin. The effects of insulin on hepatic signal transcription factor mRNA expression, proinflammatory and antiinflammatory cytokine mRNA and protein concentration were determined. Insulin administration did not change glucose or electrolyte levels, but significantly decreased proinflammatory signal transcription factors [CCAAT/enhancer-binding protein-β, signal transducer and activator of transcription-3 and-5, RANTES (regulated on activation, normal T cell expressed and secreted)] and cytokine expression in the liver and serum levels of IL-1β, IL-6, macrophage inflammatory factor, and TNFα. Insulin administration further decreased high mobility group 1 protein in the serum compared with controls. In addition, insulin increased antiinflammatory cytokine expression in the liver; serum levels of IL-2, IL-4, and IL-10; and hepatic suppressor of cytokine signaling-3 mRNA expression. Insulin modulates the inflammatory response by decreasing the proinflammatory and increasing the antiinflammatory cascade. Because glucose and electrolyte levels did not differ between insulin-treated patients and controls, we hypothesize that the effects are direct antiinflammatory mechanisms of insulin, rather than indirect, through modulation of glucose or electrolyte metabolism.