Kazuo Mizushima

Proceedings of the 23rd Autumn Meeting from October 14–16, 1981-Yonago City, Tottori, Japan

The methodology currently used in the field of physiology of intestinal absorption was reviewed and important progresses in our knowledge of mechanisms of intestinal absorption brought about by introduction of new methods were also summarized. The physiological methods currently employed can cover a broad range of investigations from those at an organ level, e.g. perfusion of intestinal segments, to those at a molecular level, e.g. transport studies in reconstituted systems with purified membrane proteins. By these methods, Na +-dependent mechanism of uphill uptake of various organic solutes and electrolytes across the brush border membrane have been largely clarified and active transport of various solutes is now explained on the basis of the concept of the secondary active transport. The mechanism of exit of solutes from the enterocytes have also been investigated in isolated cell suspensions and purified basolateral membrane vesicles, and some carriers responsible for the exit have been characterized. The charge transfer associated with organic solute transport has been studied by electrophysiological techniques. These studies indicate that organic solutes induce a Na + pathway and resultant Na + flow across the membrane causes a coupled flow of the cosubstrate. A relatively new problem is the transport of small peptides in intact form. Its physiological significance, comparative and developmental aspects are now under investigation in several laboratories. Vira l hepatitismRecent advances of its fundamental research

Abnormality of serum immunoglobulins in chronic liver disease-immune complex like substances, abnormaly basic γ-globulin, secretory IgA and anti-DNA antibody

1) Serum secretory IgA was reduced in chronic liver disease while it was increased in obstructive jaundice. 2) Serum anti-dsDNA antibody was slightly increased in chronic liver disease, especially it was significantly increased in lupoid hepatitis in which its titer paralelled with the course of disease activity. 3) Serum Clq binding activity, Clq binding inhibition activity and polyclonal rheumatoid factor binding inhibition activity were increased in chronic liver disease and their disease activity was correlated with concentration of macromolecular immune complexes which were fractionated with sucrose density gradient ultracentrifugation. 4) Abnormally basic y-globulin which was dominantly found in chronic hepatitis B sera was determined to be monomeric IgG. I t was increased in aggravation of the disease but has no correlation with Clq binding monomeric IgG. 5) Liver membrane specific lipoprotein (LP-1), Espinosas liver specific antigen (LSA), Nerenbergs hepatorenal antigen (HRA) and Tamm-Horsfall glycoprotein (THGP) had positive charge, and LP-2 and F-antigen did negative charge. 6) Human liver cell membrane fraction could not be obtained by the method of Ray or aqueous two phase polymer system which have been used for rat liver.