Reperfusion-induced changes in capillary perfusion and filtration: effects of hypercholesterolemia.
Fluid filtration rate (J(v)/S) and red blood cell velocity (V(RBC)) in individual mesenteric capillaries of normocholesterolemic (NC) and hypercholesterolemic (HC) rats were measured before and after ischemia and reperfusion (I/R). In NC rats, a correlation was found between baseline J(v)/S and the percent of the feeding arteriole length that was paired (<15 micrometer) with a postcapillary venule (A-V pairing), but not in the HC group. Additionally, in NC rats only, a correlation was found between baseline V(RBC) and A-V pairing. In capillaries in which A-V pairing was substantial (>20%), V(RBC) dropped after reperfusion in the HC group (54% of baseline; P < 0.05), but not in the NC group (79%). The decrease in V(RBC) in HC rats could be attenuated by a P-selectin antibody (PB1.3). PB1.3 was also able to attenuate the increase in I/R-induced capillary J(v)/S in HC rats (median increase = 1.26-fold vs. 1.53-fold without PB1.3). These data suggest a role for A-V pairing in capillary perfusion in NC rats and a potential role for P-selectin in I/R-induced microvascular dysfunction in HC rats.
Harris
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Bioengineering Program, Pennsylvania State University, University Park, Pennsylvania 16802-6804, USA. nrh1@psu.edu
D000818:Animals; D002196:Capillaries / Q000503:physiopathology; D002199:Capillary Permeability; D006937:Hypercholesterolemia / Q000150:complications* / Q000503:physiopathology*; D008297:Male; D008833:Microcirculation; D019007:P-Selectin / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D012016:Reference Values; D015427:Reperfusion Injury / Q000150:complications* / Q000503:physiopathology*; D013152:Splanchnic Circulation
D019007:P-Selectin