Dose-response relationships between platelet activating factor and permeability--surface area product of FITC-dextran 150 in the hamster cheek pouch.
Changes in vascular permeability to FITC-dextran 150 associated with topical application of platelet activating factor (PAF) in the hamster cheek pouch preparation were calculated using a mathematical model (Baxter et al., Microvasc. Res. 34:336, 1987). Least square estimates of apparent permeability-surface area product (PS) and interstitial diffusion coefficient (D) were calculated from the data and the mathematical model using a Marquart optimization algorithm. Calculated PS products varied with applied PAF concentration while the best-fit estimate of apparent D remained constant at 10.5 X 10(-10) cm2/s. Average baseline PS was 16.5 X 10(-8) ml/s. PS increased to 45.2 X 10(-8) ml/s and 52.3 X 10(-8) ml/s with application of 10(-8)M and 10(-7)M PAF, respectively. A further increase in PAF concentration to 10(-6)M decreased the calculated PS product to 30.5 X 10(-8) ml/s. PAF is a potential modulator of macromolecular permeability in the microcirculation. This is the first study which quantitates the changes in PS of FITC-dextran 150 as a function of PAF concentration.
Bekker
A Y
AY
Department of Physiology, UMDNJ - New Jersey Medical School, Newark 07103-2757.
Dillon
P K
PK
Paul
J
J
Ritter
A B
AB
Durán
W N
WN
D000818:Animals; D002199:Capillary Permeability / Q000187:drug effects*; D002610:Cheek; D006224:Cricetinae; D003911:Dextrans / Q000493:pharmacokinetics*; D004305:Dose-Response Relationship, Drug; D008433:Mathematics; D008962:Models, Theoretical; D010972:Platelet Activating Factor / Q000494:pharmacology*; D012984:Software; D013499:Surface Properties
D003911:Dextrans; D010972:Platelet Activating Factor