title: Leakage responses to L-NAME differ with the fluorescent dye used to label albumin.
abstract: Nitric oxide synthase (NOS) inhibitors have been reported to increase as well as to decrease microvascular transport of macromolecules in a variety of models. This study was performed to determine whether the influence of NOS inhibition on albumin leakage was dependent on the fluorescent dyes used to label albumin. Albumin leakage was assessed in rat mesenteric venules during control conditions and after exposure to the NOS inhibitor NG-nitro-L-arginine methyl ester (L-NAME). Albumin was labeled with any one of four dyes: FITC, sulforhodamine 101 [Texas Red (TR)], dichlorotriazinyl aminofluorescein (DTAF), or Oregon Green 514 (OG). Superfusion with L-NAME (10(-4) M) was accompanied by an increase in leakage of FITC-labeled albumin (n = 12) but not of albumin labeled with DTAF (n = 10), TR (n = 10), or OG (n = 4). In vessels perfused with both FITC- and TR-labeled albumin (n = 12), superfusion with L-NAME increased leakage of FITC- but not TR-labeled albumin. In conclusion, albumin leakage responses to L-NAME differ among various fluorescent dyes. Therefore, caution is advised in comparison of albumin leakage results that utilize different fluorescent dyes.
authors.affiliation: Department of Internal Medicine, Pulmonary and Critical Care Division, and Department of Physiology, University of Missouri-Columbia, Columbia, Missouri 65212, USA.
authors.forename: R E
authors.initials: RE
authors.lastname: Rumbaut
authors.forename: N R
authors.initials: NR
authors.lastname: Harris
authors.forename: A J
authors.initials: AJ
authors.lastname: Sial
authors.forename: V H
authors.initials: VH
authors.lastname: Huxley
authors.forename: D N
authors.initials: DN
authors.lastname: Granger
mesh_terms: D000818:Animals; D002199:Capillary Permeability / Q000187:drug effects*; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D005456:Fluorescent Dyes; D008297:Male; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012710:Serum Albumin, Bovine / Q000493:pharmacokinetics*; D013152:Splanchnic Circulation / Q000187:drug effects / Q000502:physiology; D014699:Venules / Q000187:drug effects / Q000502:physiology
chemical_list: D004791:Enzyme Inhibitors; D005456:Fluorescent Dyes; D012710:Serum Albumin, Bovine; D019331:NG-Nitroarginine Methyl Ester