Determination of microvessel permeability and tissue diffusion coefficient of solutes by laser scanning confocal microscopy.
Interstitium contains a matrix of fibrous molecules that creates considerable resistance to water and solutes in series with the microvessel wall. On the basis of our preliminary studies, by using laser-scanning confocal microscopy and a theoretical model for interstitial transport, we determined both microvessel solute permeability (P) and solute tissue diffusion coefficient (D) of alpha-lactalbumin (Stokes radius 2.01 nm) from the rate of tissue solute accumulation and the radial concentration gradient around individually perfused microvessel in frog mesentery. P(alpha-lactalbumin) is 1.7 +/- 0.7(SD) x 10(-6) cm/s (n = 6). D(t)/D(free) for alpha-lactalbumin is 27% +/- 5% (SD) (n = 6). This value of D(t)/D(free) is comparable to that for small solute sodium fluorescein (Stokes radius 0.45 nm), while p(alpha-lactalbumin) is only 3.4% of p(sodium fluorescein). Our results suggest that frog mesenteric tissue is much less selective to solutes than the microvessel wall.
Fu
Bingmei M
BM
Department of Mechanical Engineering, Cancer Institute, University of Nevada, Las Vegas, 4505 Maryland Parkway, Box 454027, Las Vegas, NV 89154, USA. fu@ccny.cuny.edu
Adamson
Roger H
RH
Curry
Fitz-Roy E
FR
D000818:Animals; D002199:Capillary Permeability / Q000502:physiology*; D003198:Computer Simulation; D004058:Diffusion; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D007768:Lactalbumin / Q000493:pharmacokinetics*; D008297:Male; D008643:Mesentery / Q000166:cytology / Q000502:physiology; D008833:Microcirculation / Q000166:cytology* / Q000502:physiology*; D018613:Microscopy, Confocal / Q000379:methods*; D008955:Models, Cardiovascular; D011894:Rana pipiens
D007768:Lactalbumin