Acta Medica Okayama volume18 issue4

An intestinal absorption test with the use of D-xylose has been performed on 19 patients including 3 of acute hepatitis, 7 of chronic hepatitis and 9 of liver cirrhosis, and the following results were obtained. 1) The 5 hr urinary excretion and 2 hr blood level of D-xylose tend to increase in patients of acute and chronic hepatitis with severer disorder of liver functions. 2) The standard deviations of the 5 hr urinary excretion and 2 hr blood level of D-xylose are larger in liver cirrhosis than in the other liver diseases. Those cases having severe disorder of liver functions are found to be diminished in 5 hr urinary excretion and 2 hr blood level of D-xylose. 3) A decrease in the absorption of D-xylose from the small intestine of liver cirrhosis might be caused by the diminished surface area of villi of the small intestine.

For the purpose to reveal the mechanism of the stimulated erythropoiesis in anemic condition, the author observed the numerical changes of the erythroblasts from normal rabbit bone marrow cultured under the environment of varied oxygen tensions, and revealed the following: 1. The erythroblasts incubated with air are increased after 24 to 48 hours and decreased gradually disappearing by 120 hours with a corresponding increase of erythrocytes. But no active proliferation of the stem cells or proerythroblasts is observed, all the cells have differentiated to erythrocytes. Hyperoxygen tension suppresses the increase of erythroblasts slightly, while hypoxygen tension stimulates the increase. Data suggest that the cell number destined to be ineffective erythropoiesis is regulated by oxygen tensions of the environment. 2. Basophilic erythroblasts are reduced in number from the beginning showing not any increasing tendency. The reducing rate is almost the same among those cultured under the hypo- and hyperoxygen tension, comparable to that incubated with air. 3. The hypoxygen tension brings about a marked increase in the number of orthochromatic erythroblasts with a decrease in polychromatic erythroblasts suggesting an accelerated cell differentiation, while the hyperoxygen tension elicits the suppression in the formation of orthochromatic erythroblasts with suppressed differentiation. Data also show the lack of denucleation mechanism in polychromatic stages in vitro differing from the case of the bone marrow of anemic animal.

Intestinal absorption tests with the use of D-xylose were conducted on 12 healthy Japanese subjects and the following results were obtained. 1) The mean value of the urinary xylose excretion within five hours after an oral administration of 25 g of D-xylose was 8.07 g and standard error of the mean was 0.11. The mean of urinary excretion was higher than most of previous reports. 2) The 5 hr urinary excretion after intravenous administration of 25 g D-xylose in normal subjects was almost equal to that reported by BUTTERWORTH et al. 3) The rate of D-xylose absorption from the intestine of normal Japanese subjects was higher than that in Europe, Canada and U. S. A. 4) The differences in the pattern of the intestinal absorption of D-xylose in normal individuals seemed to originate from different dietary habit continued over the period of many years, especially of carbohydrate contents.

An anatomical study was made to follow the degeneration of fibers by means of Marchi technique in cat after making experimentally lesion in Forel H field. As the results the following conclusions were reached. 1) The ipsilateral distribution of the degenerated granules was in the anterior sigmoid gyrus, caudate nucleus, putamen and globus pallidus, thalamic nuclei medial to the internal medullary lamina, substantia nigra, rubrocerebellar system, medial longitudinal fascicle system, mesencephalic and pontine reticular formation and medial lemniscus. 2) There was also contralateral distribution to the interpositus and dentatus nuclei of the cerebellum via brachium conjunctivum, to globus pallidus via supraoptic commissure, to subthalamic region and substantia nigra via supramammilary commissure, and to red nucleus via tegmental decussaion. 3) The degeneration is so extensive that the Forel H-field seems to be the cross road of the extrapyramidal system in association with brainstem activating system.

Some investigations have been done on the relationships between the swelling-shrinkage change, oxygen consumption and state of oxidation-reduction of pyridine nucleotides of mitochondria, and between the swelling-shrinkage change of mitochondrial structure by Ca2+ and accumlation of Ca45 in rat liver mitochondria. A parallel relationship is observed between the Ca2+ induced swelling and Ca2+ accumulation. Both of them require Pi but not Mg2+, ATP and exogenous respiratory substrates and are inhibited by respiratory inhihitors or uncouplers of oxidative phosphorylation but not by the inhibitors of phosphorylating respiration. In this case the Ca2+ is transported with the phosphate even in ice cold. Even in the presence of antimycin A, moreover, Pi-dependent Ca2+ accumulation and Ca2+ induced swelling can be overcome by addition of ATP, which are inhibited by oligomycin. In the presence of Pi, mitochondria show shrinkage by addition of Ca2+ before the high amplitude swelling, which is closely correlated to the electron ransport chain and phosphorylation process of mitochondria, and the pattern of the mitochondrial shrinkage is quite similar to that observed in the case of respiratory control by ADP in intact mitochondria. This shrinkage of mitochondria is inhibited by respiratory inhibitor or uncoupler of oxidative phosphorylation but not by the inhibitor of phosphorylating respiration. From these data, therefore, it is considerd that the Ca2+ accumulation and Ca2+ induced shrinkage-swelling of mitochondria require the energy of oxidative phosphorylation with respect to the initial step before the oligomycin block.

In the previous papers, it has been shown that the substrate inhibition of xanthine oxidase (xanthine: O2 oxidoreductase, EC 1. 2. 3. 2) induced by excess purines requires a small amount of exogenous metallic ions. Among these ions, Cu²+ was the most typical one. At any stage of enzyme reaction, the inhibition began immediately on addition of a small amount of Cu²+ such as 6.6 X 10-7 M. Since the depressed activity was not restored by the addition of chelating agents such as histamine and EDTA, it was suggested that the substrate, Cu²+ and enzyme form a stable inactive enzyme complex, from which chelating agent can no longer remove Cu. The present communication describes the further investigations concerned with the formation of the substrate-enzyme complex in the presence of Cu²+ and with the catalytic nature of this complex on other substrate and acceptor systems.

In the course of studies on the cleavage reaction of S-(isopropylcarboxymethyl) glutathione (GSIV) into isovalthine in kidney homogenate or glutathionase preparation, it has sometimes been observed that the amount of isovalthine formed is far less than that of GSIV decomposed¹. Furthermore, when such reaction mixture is analyzed on an automatic amino acid analyzer, prominent peak corresponding to the reasonable amount of S-(isopropy1carboxymethyl)cysteinylglycine which is an expected intermediate of the GSIV cleavage reaction cannot be found up to 400 effluent ml. Though several reasons may be considered for the explanation of the above curious phenomenon, the effect of cystathionase on isovalthine is at first examined here. But the result was negative. L- and L-Alloisovalthineused as substrate were prepared by the method of OHMORI². Homoserine and purified cystathionase in ammonium sulfate solution prepared according to the method of GREENBERGB³ were kindly furnished by Prof. M. Suda of Osaka University. Incubation mixture contains 0.1 ml of enzyme solution, 1.0 ml of 0.2 M borate buffer (pH 8.0) containing 2×10-³M cysteine, 0.lml of 0.1 M substrate, and 0.8ml of deionized water containing 5×10-4M EDTA. The mixture was shaken at 37°C for 30 minutes in the air. The reaction was terminated by adding 2ml of 10% trichloroacetic acid and the α-keto acids formed were determined by the method of FRIEDEMANN and HAUGEN4 with a following modification: toluene extract was washed once with 8 ml of 10% sodium sulfate. The results obtained are summarized in Table l. When the reaction mixtures are analyzed before or after incubation on an automatic amino acid analyzer, the amount of L- or L-Alloisovalthine is found to be unchanged. Furthermore, as indicated in Table 1, L-isovalthine showed no inhibitory effect on the homoserine cleavage by cystathionase. Since amino acid oxidases have already been reported to have no effect on isovalthine³, the curious phenomenon above cited may have to be explained by other reaction mechanism such as transpeptipation reaction.