The permeability of human skin to electrolytes

Abstract

The epidermis is not only a protective covering against mechanical injury, but presumably protects the body also from diffusion inwards of foreign sub stances or diffusion outwards of normal constituents of the blood. In a previous paper (Whitehouse, Hancock and Haldane, 1932) it was shown that though the epidermis is permeable to water, and the actual permeation is under physiological control and plays an important part in the regulation of body-temperature, yet salts and colloidal substances do not appear to diffuse through the epidermis, so that in this respect the epidermis seems to play the part of a semi-permeable membrane. The question of the permeability of the epidermis to various substances which are met with in mining and other operations, or are applied with a remedial object, is of much practical interest, and in connection with the treatment of mining accidents from burning, the apparent impermeability of the outer epidermis to colloidal solutions of tannic acid and ionized solutions is of special importance. It is presumably the dense stratum lucidum of the external epidermis that tends to stop diffusion.The present investigation deals with the question whether the skin is entirely impermeable to electrolytes in solution. The choice of suitable substances for the tests was necessarily limited to elements which are either not present in urine or blood, or present in only very small amounts, and which could also be detected and determined very accurately.Lithium as a kation was chosen for the first series of experiments, since it is only present in very minute amounts in human blood and urine, and a very small increase in its concentration can be detected. A spectrographic method similar to that used previously by one of us (Ramage, 1929) was used to test for the presence of lithium. A measured volume of urine was rim on to a piece of MunktelFs ashless filter paper weighing about 0*11 gm. After drying in a steam oven, the paper was made into a tight roll and burnt in an oxy-coal gas flame issuing from a fused silica burner, the light being focussed by a quartz lens on the slit of the spectrograph. The piece of filter paper absorbed 0*1 c.c. of fluid easily and, if a larger quantity was necessary for the analysis, it was on May 9, 2018 http://rspb.royalsocietypublishing.org/ Downloaded from

Differential Roles of Layers of Human Epigastric Skin on Diffusion Rate of Water

“…Whitehouse and others 5 have stated that the stratum lucidum is chiefly responsible for the in¬ hibition of diffusion. In these studies it was not possible to demonstrate the stratum lucidum in the sections taken from the epigastrium.…”

Spectrographic Analysis of Plants and Soils

“…Further papers by this method on animal tissues are Sheldon & Ramage (1931) and Ramage, Sheldon & Sheldon (1933). Whitehouse & Ramage (1933) determined Li in an attempt to measure the permeability of the skin to electrolytes. Whilst Ramage's work had a very stimulating effect in encouraging subsequent research and development of methods, it must be realized that in the light of our present knowledge of interference effects and the behaviour of trace constituents in bases of different composition, quite considerable errors may have arisen from his practice of comparing solid ashes in filter paper with standards added to the paper in solution and then evaporated.…”