Acute blood stasis reduces interstitial uptake of albumin from intestinal microcirculatory networks.
Temporary blood flow stoppage occurs in a greater percentage of the capillaries when blood flow to organs is reduced. Previous studies on the small intestine have suggested that acute blood stasis (< or = 10 min) results in expression of negative charge, not present when blood flow is brisk, on the luminal surface of mucosal capillaries. Negative surface charge would tend to reduce transcapillary passage of albumin from blood to interstitium, since albumin is also negatively charged. Here we test the hypothesis that acute blood stasis reduces the interstitial uptake of albumin from mucosal capillary networks in rat small intestine in situ. Animals were subjected to two treatments, which included intestinal blood flow and acute stasis. After each treatment, fluorescent albumins were perfused into the intestinal circulation, and then interstitial fluorescence was recorded using fluorescence 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 interstitial fluorescence intensity values. These results may have relevance to the mechanisms by which albumin flux in the small intestine is synchronized with digestion and fasting, which are associated with high and low intestinal blood flow, respectively.
Merkle
C J
CJ
College of Nursing and Department of Physiology, University of Arizona, Tucson 85721, USA.
Wilson
L M
LM
Baldwin
A L
AL
D000818:Animals; D001783:Blood Flow Velocity; D002196:Capillaries / Q000378:metabolism*; D004563:Electrochemistry; D016650:Fluorescein-5-isothiocyanate / Q000031:analogs & derivatives; D005456:Fluorescent Dyes; D007413:Intestinal Mucosa / Q000098:blood supply; D007422:Intestines / Q000098:blood supply*; D007511:Ischemia / Q000378:metabolism*; D008297:Male; D008856:Microscopy, Fluorescence; D051381:Rats; D017207:Rats, Sprague-Dawley; D012709:Serum Albumin / Q000378:metabolism*; D012710:Serum Albumin, Bovine
D005456:Fluorescent Dyes; D012709:Serum Albumin; C039217:fluorescein isothiocyanate bovine serum albumin; D012710:Serum Albumin, Bovine; D016650:Fluorescein-5-isothiocyanate