Process of critical movement of intravascular fluid into intracellular space.

A CCORDING to Chambers and Zweifach, water and water soluble substance move through only intercellular cement and lipophilic substances, 02 and CO2 move mainly through cell membrane. Therefore, the main factor which determines the capillary permeability to water is the porosity of inter-cellular cement. Almost all of physiological phenomena can be explained reasonably by considering that the intercellular cement has many small pores of 30-50 • ð in diameter. capillary of all organs has definite intercellular pathway or gap. According to Danielli, cell membrane is composed of lipoprotein complex. The basement membrane is a homogenous membrane of 500-600 • ð in width, and its chief component has been considered to be mucopolysaccharides which is substratum of connective tissue in general. While the substratum of connective tissue, however, disappears during the process of making specimen for electron micro-scopy, the basement membrane stains densely with osmium and shows selective and destructive change by ANTU injection (ANTU is a lipophilic substance !). Therefore, the basement membrane differs definitely from substratum of connective tissue and seems to be rich in lipids. Intercellular pathway of capillary wall is filled with same substance as basement membrane. In summary, all the basement membrane, cell membrane and intercellular pathway which determine the permeability to water are rich in lipids. When animals are fed a diet deficient in essential fatty acids for a certain period of time, fatty acid content in the organs shows a typical pattern of change, i. e. decrease in dienoic and tetraenoic acids and increase in trienoic acid. Essential fatty acids (abbreviated as EFA) in the skin also show same change. In parallel with this change, insensible water loss increases remarkably. These facts indicate that capillary permeability of the skin increases markedly in EFA-deficient organism. As is well known, the lung has the largest amount of collagenous tissue same as the subcutaneous tissue and its tissue tension against extravasation of fluid is very low. Therefore, the lung develops edema more easily than the