ACUTE BLOOD STASIS REDUCES INTERSTITIAL UPTAKE OF ALBUMIN FROM INTESTINAL MICROCIRCULATORY NETWORKS

Temporary blood Bow stoppage occurs in a greater percentage of the cap illaries when blood flow to organs is reduced. Previous studies on the small intestine have suggested that acute blood stasis (less than or equal to 10 min) results in expression of negative charge, not present when blood flow is brisk, on the luminal surface of mucosal capillari es. Negative surface charge would tend to reduce transcapillary passag e of albumin from blood to interstitium, since albumin is also negativ ely charged. Here we test the hypothesis that acute blood stasis reduc es the interstitial uptake of albumin ii om mucosal capillary networks in rat small intestine in situ. Animals were subjected to two treatme nts, which included intestinal blood flow and acute stasis. After each treatment, fluorescent albumins were perfused into the intestinal cir culation, and then interstitial fluorescence was recorded using fluore scence microscopy. Images were later quantified by computer analysis. After brisk blood flow, but not after acute blood stasis, fluorescence rapidly appeared in the interstitium and resulted in higher interstit ial fluorescence intensity values, These results may have relevance to the mechanisms by which albumin flux in the small intestine is synchr onized with digestion and fasting, which are associated with high and low intestinal blood flow, respectively.