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T Matsuda

Publications and source records attributed to T Matsuda.

At least 1,639 records · Page 91Linked to original sources
PubMed1978

Effect of cyclic AMP on placental active transport of amino acid in rats.

In pursuit of the probable relationship of cAMP to the placental active transport of amino acids as suggested by our previous human data, experiments were done in this study with dibutyryl cAMP and theophylline loaded in pregnant rats to examine the changes in level of 14C-lysine in the maternal liver, placenta and fetus. The results are: (1) Loading of dibutyryl cAMP had no effect on the uptake of 14C-lysine in the maternal liver, placenta or fetus, except that the correction of the values with its concentration in the maternal blood revealed only a slightly significant elevation in the value in each of them 30 min after the loading. (2) Loading of theophylline significantly increased the uptake of 14C-lysine in all these organs. (3) The content of cAMP in the placenta significantly increased with the loading of theophylline. These results have led the authors to believe that endogenous cAMP is significantly linked with the placental active transport of amino acids, though there is no apparent contribution to it by exogenous cAMP.

Amino Acids↗
PubMed1978

Regulation of regional perfusion distribution in the lungs. Experimental model and effect of alveolar pressure.

An experimental model for studying changes in regional perfusion distribution in the lungs of a dog was described. The right upper lobe was separated in vivo from the rest of the lungs by a balloon catheter and gas exchange of the lobe was artificially done asynchronously with the rest of the lungs by using a gas of interest at a prescheduled aveolar pressure. 99mTc-albumin microsphere was the agent of choice for multiple sequential studies in one dog. Alveolar gas composition reached a plateau after the 4th inflation of the right upper lobe. Effect of alveolar pressure on regional perfusion distribution was studied by using nitrogen and air as exchange gases. Perfusion distribution in the right upper lobe was the least at the maximal alveolar pressure of 14 to 19 cm H2O, while it was the greatest at the tidal maximal alveolar pressure of 1 to-1cm H2O with either gas. Alveolar hyperinflation in a localized lung region due to the increase in regional alveolar pressure reduced regional perfusion distribution.

Air↗
PubMed1978

Characterization of thiamine diphosphatase in rat small intestine.

The properties of thiamine diphosphatase (TDPase) and p-nitrophenylphosphatase (p-NPPase) in rat small intestine were investigated. TDPase activity, like p-NPPase activity, was high in the mucosa and in the proximal region. Both activities were high in the membrane-associated fractions of the duodenal mucosa. Furthermore, TDPase had the same properties as intestinal alkaline phosphatase (al-Pase). These results suggest that thiamine diphosphate (TDP) and p-nitrophenylphosphate (p-NPP) are hydrolyzed by a single enzyme, al-Pase, in the intestine.

4-Nitrophenylphosphatase↗
PubMed1978

Centrally mediated hyperglycemia by 6-aminonicotinamide.

Some metabolic changes induced by the intraventricular administration of 6-aminonicotinamide (6-AN) were studied in mice. Five or ten microgram/animal of 6-AN produced a marked hyperglycemia, lowered glycogen content in the brain and liver, and reduced the adrenal epinephrine content. Adrenalectomy or hexamethonium prevented 6-AN-induced hyperglycemia and decrease of glycogen content in the liver but not in the brain. Decrease of adrenal epinephrine content induced by 6-AN was overcome by hexamethonium. Pretreatment with 6-AN (10 microgram/animal) markedly lowered the toxic action, but not the hypoglycemic action, of a large dose of insulin.

6-Aminonicotinamide↗
PubMed1978

[Studies on the fibrinolytic system in ruptured intracranial aneurysm.--Part 2: Fibrinogen changes in acute stage of SAH as a risk factor of the ischemic complications following vasospasm (author's transl)].

Repeated fibrinogen determination were made in 24 patients suffering from subarachnoid hemorrhage(SAH), in order to know the influence of blood content of fibrinogen upon the ischemic complications following vasospasm. In 11 cases (group II) among those 24 patients admitted within two weeks after the last SAH due to ruptured intracrainal aneruysm, a rise in fibrinogen over 600 mg/dl occurred, while in remaining 12 cases (group I) the levels of fibrinogen were kept below 600 mg/dl during the acute stage. In cases of group II, fibrinogen began to increase in accordance with the augmentation of vasospasm and reached to peak within 4 to 9 days after the onset of SAH. Blood viscosity also increased showing positive correlation with the increase in fibrinogen, and rose over 1.5 times normal value when fibrinogen exceeded 600 mg/dl. Reduction of anti-thrombin III was also observed in group II patients previous to the increase in fibrinogen, suggesting the occurrence of hypercoagulability in association with the appearance of vasospasm. In most cases of group II, their neurological signs deteriorated markedly at the time when fibrinogen rose over 600 mg/dl. The mortality in group II whose fibrinogen increased over 600 mg/dl was of 6 of 11, with poor recovery of function among the survivors; of those with levels below 600 mg/dl (group I), only 1 of 12 died and all of remaining 11 made a reasonably good functional recovery. These facts suggest that the increase in fibrinogen would cause the aggression of the ischemic complications following vasospasm through the diminution the cerebral microcirculation induced by the raised blood viscosity, and the critical level of fibrinogen increase as the alarming sign for the ischemic complications was 600 mg/dl. One should attract attention to the changes of fibrinogen level as one of the risk risk factors in acute stage of SAH.

Acute Disease↗
PubMed1978

Studies on immunosuppression by cobra venom factor. II. On responses to DNP-Ficoll and DNP-Polyacrylamide.

We have reassessed the effects of CVF administration on the humoral responses to two T-independent immunogens: DNP-Ficoll and DNP-Polyacrylamide. With high immunogen doses, little or no evidence of suppression was found. However, when the immunizing dose was reduced, suppression of both IgG and IgM responses became apparent. As indicated in a previous report, the immunosuppressive effect of CVF on T-dependent responses may result not only from C depletion but also from the generation of C cleavage products that may impair the auxiliary contribution of macrophages to the generation of these humoral responses. A similar mechanism may be applicable to the suppression of antibody production to DNP-Ficoll and DNP-PAA in view of recent reports showing a macrophage requirement for the response to these immunogens.

Acrylamides↗
PubMed1978

Studies on immunosuppression by cobra venom factor. III. On early responses to sheep erythrocytes in C5-deficient mice.

CVF administered before immunization can profoundly depress humoral responses in C-sufficient mice. In AKR/JC5- mice given CVF before i.v. immunization with SRBC, only IgG levels were depressed, IgM titers being equivalent to those of untreated controls. The immunosuppressive effect became inapparent when the i.p. route of immunization was adopted. In DBA/2J C5- mice reduction of both IgG and IgM titers was observed irrespective of the route of immunization. The degree of suppression was, however, much more marked when mice were challenged intravenously. Essentially identical results were obtained with C5+ DBA/1J mice. These studies indicate that immunosuppression by CVF is unrelated to activation of the late C components. The significance of these findings is discussed with reference to the possibility that the generation of biologically active C fragments in conjunction with a C3 deficiency may account for immunosuppression by CVF.

Animals↗