Altering Diffusion Rates

Abstract

In a recent article concerned with the relation between glucose absorption rate and serum globulin concentration in man the authors showed a direct linear relationship between glucose absorption rate in the jejunum and the serum γ-giobuiin concentration, with the glucose absorption rate decreasing as the γ-globulin concentration increased. (1) We have previously shown a direct linear relationship between the diffusivity of glucose in plasma and the γ-globulin concentration (2), which is almost exactly that seen in the previously-mentioned experiments. In both cases the variation of γ-globulin was over the physiological range, although those ranges were slightly different (Zambian African subjects for the glucose absorption studies and USA Caucasians for the diffusibity work). The striking similarity between the two sets of data brings to mind an interesting question of whether diffusion through plasma is of major importance in determining the rate of uptake and release of solutes by and from tissues.