Capillary permeability to endogenous macromolecules in the equine digit.
Microvascular permeability characteristics were evaluated in digits of 7 adult horses. After capillaries were isolated and an extracorporeal perfusion circuit for the digit was established, a lymphatic vessel draining the distal portion of the phalangeal region was cannulated at the level of the coronary band. Venous pressure was increased in a stepwise manner, and lymph flow, lymph protein concentration (Cl), and plasma protein concentration (Cp) were determined after measured variables were allowed to reach steady state. Lymph-to-plasma protein concentration ratios (Cl/Cp) and lymph and plasma oncotic pressures were determined from samples collected during steady state. The osmotic reflection coefficient was determined after Cl/Cp became constant, regardless of increasing lymph flow, and was expressed as 1--Cl/Cp. The osmotic reflection coefficient for the digit was 0.67. Seemingly, the microvasculature bed of the digit was relatively permeable and could maintain only 67% of the endogenous macromolecules within the vasculature.
Allen
D
D
Department of Large Animal Medicine, College of Veterinary Medicine, University of Georgia, Athens 30602.
Korthuis
R J
RJ
Clark
E S
ES
D000818:Animals; D001798:Blood Proteins / Q000502:physiology*; D002199:Capillary Permeability; D005260:Female; D005552:Forelimb / Q000098:blood supply; D006736:Horses / Q000502:physiology*; D006801:Humans; D008196:Lymph / Q000502:physiology*; D008297:Male; D014034:Toes / Q000098:blood supply*
D001798:Blood Proteins