DOBUTAMINE MAINTAINS INTESTINAL VILLUS BLOOD-FLOW DURING NORMOTENSIVEENDOTOXEMIA - AN INTRAVITAL MICROSCOPIC STUDY IN THE RAT

Purpose: The gut plays a pivotal role in sepsis. Intestinal hypoperfus ion with subsequent ischemia leads to translocation of endotoxin, Dobu tamine has been demonstrated to increase mesenteric blood flow during endotoxic shock; however, its effects on mucosal blood flow especially in intestinal villi is not known. Therefore, we investigated its infl uence on the blood flow and the arteriolar diameters in intestinal vil li in a model of normotensive endotoxemia. Materials and Methods: Twen ty-one male Wistar rats were divided into three groups: (1) control, s aline; (2) endotoxin, endotoxin 1.5 mg/kg during 60 minutes; and (3) d obutamine, endotoxin 1.5 mg/kg (60 minutes) and dobutamine 2.5 mu g/kg /min during 120 minutes. Villus blood flow and arteriolar diameters we re determined at 0 minutes, 60 minutes, and 120 minutes in each group using intravital microscopy. Results: Villus blood flow was constant i n the control group, significantly reduced at 120 minutes in the endot oxin group (120 minutes, 55.1 +/- 7.4%), and remained at baseline valu es in the dobutamine group. The arteriolar diameters remained constant in the control and the dobutamine groups, but they were significantly reduced in the endotoxin group at 120 minutes (7.8 +/- 0.2 to 6.5 +/- 0.7 mu m) Conclusion: Our results indicate that in rats with normoten sive endotoxemia, arteriolar diameters and blood flow in intestinal vi lli were reduced. Dobutamine prevented arteriolar constriction and mai ntained villus blood flow at preendotoxemic values. Copyright (C) 1997 by W.B. Saunders Company.