Alanyl-glutamine dipeptide does not affect hemodynamics despite a greater increase in myocardial heat shock protein 72 immunoreactivity in endotoxemic sheep

The possible beneficial effect of supplemental glutamine (Gln) in criticall y ill patients has been suggested to be mediated by the induction of the cy toprotective heat shock proteins (HSP)32 and HSP72. There is evidence that HSP72 and HSP32 have opposite effects on the hemodynamic situation during e ndotoxemia. Therefore, the effect of Gin supplementation on the cardiovascu lar system is not clear. We investigated the effect of alanyl-Gln (Ala-Gln) dipeptide on cardiovascular function in healthy and endotoxemic sheep, Ten sheep catheterized for chronic studies received Ala-Gln 700 mg/(kg.d) [equ al to 470 mg/(kg.d)Gln] on 4 consecutive days, and 10 sheep received NaCl ( 9 g/L) as the control solution. On d 4, four sheep of each group were kille d and myocardial samples were taken for immunohistochemistry. The remaining sheep received a continuous infusion of endotoxin [Salmonella typhosa, 10 ng/(kg.min)]. Hemodynamic parameters were measured before application of Al a-Gln or the control solution, and during endotoxemia. Myocardial HSP72 imm unoreactivity was determined by immunohistochemistry. After 24 h of endotox emia, the sheep exhibited a hyperdynamic circulation. No difference was fou nd in the hemodynamic parameters between treatment and control group. Ala-G ln treated sheep had a greater increase in myocardial HSP72 immunoreactivit y compared with controls after (P < 0.05) but not before endotoxemia. In su mmary, Ala-Gln increased HSP72 immunoreactivity after endotoxemia, but did not alter hemodynamic parameters. Thus, Ala-Gln supplementation does not se em to aggravate the hyperdynamic circulation in endotoxemic shock.