Transport of potassium-42 from blood to tissue in isolated mammalian skeletal muscles.

RENKIN, EUGENE M. Trans-ort of jwtassium-q2 from blood to pissue in isolated mammalian skeletal muscles. Am. J. Physiol. Ig7(6): no5-121o. I g5g.A method is described for studying transcapillary diffusion of K42 in isolated perfused muscles of dogs. Blood flow and arteriovenous K42 differences are mea+ ured and blood-tissue clearance calculated by the Fick principle. A theoretical relation between blood flow and blood-tissue clearance is developed for a uniform circulation characterized by a constant permeability-surface area product (PS). The experimental observations conform reasonably close1 y o prediction. However, systematic variation in measured PS L roduct with changes in blood flow and vascular resistance indicate that the capillary circulation is not uniform.