THE PERMEABILITY OF THE SYNOVIAL MEMBRANE

¹ Wilkie Surgical Research Laboratory and the Department of Pharmacology, University of Edinburgh

The permeability of the synovial membranes was studied by injecting intravenously a series of dyes in rabbits and cats, and perfusing the knee joints afterwards.

It was found that only dyes of acid character reach the joint cavity and appear in the perfusate. The amount excreted was in direct proportion to the diffusibility of the dye.

Alkaline dyes were not excreted into the joint cavity, irrespective of their diffusibility. The importance of this fact for joint pathology is stressed.

The permeability of the inflamed synovial membrane is considerably diminished compared with the normal. It is proposed that this fact should be utilised as a functional test of joints for diagnostic purposes, in analogy to the dye excretion tests of the kidney.

Sod. salicylate and Prontosil appeared in the perfusate in large quantity. It is suggested that the method of joint perfusion offers possibilities for building up a systematic pharmacology of joints.

I wish to express my thanks to the Medical Research Council for their grant and to Professor A. J. Clark for the interest taken in the experiments.