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M Takeda

Publications and source records attributed to M Takeda.

At least 1,045 records · Page 58Linked to original sources
PubMed1979

Stimulation by subsynaptosomal fractions of transmitter efflux from plain synaptic vesicle fraction.

The effects were investigated of purified subsynaptic fractions on the efflux of radioactivity from a plain synaptic vesicle fraction which had incorporated [3H]dopamine. About 50% of the radioactivity incorporated into the plain vesicles (120 microgram protein) was liberated on exposure to purified synaptic membranes (30 microgram protein). The synaptic membrane-dependent efflux appeared to depend on both adenosine triphosphate and divalent cations, especially Ca2+. Of the sub-cellular fractions used, the heavy microsomal fraction showed the same effects as the synaptic membrane fraction. Purified synaptic junctions exhibited the strongest stimulating effects: the efflux was 2 times greater than that observed with synaptic membranes. The stimulating effects of myelin were less than one-seventh of those of synaptic junctional fraction. These observations may indicate that the transmitters are liberated by interaction of vesicle membrane with synaptic membrane in the presence of ATP and divalent cations.

Adenylyl Imidodiphosphate↗
PubMed1979

Analysis of pure pancreatic juice in patients with chronic alcoholism.

To elucidate early biochemical changes of pancreatic juice and their reversibility in chronic alcoholics, pure pancreatic juice was collected from 23 chronic alcoholics by endoscopic retrograde catheterization of the papilla. Samples were collected at 1 minute intervals for 20 minutes after intravenous injection of secretin (Eisai, 1 U/kg) and for 10 minutes after CCK-PZ injection (Boots, 1 U/kg). Volume, bicarbonate concentration, protein concentration and three hydrolases were determined. Following results were obtained. (1) Five patients showed hypersecretory state. Four of the five patients showed hyperconcentration of protein. (2) Seventeen patients showed hyposecretory state. Lipase secretion was most frequently affected (94%). Maximal bicarbonate concentration was the next to be affected (82%). Amylase and chymotrypsinogen secretion were less frequently affected (65%). Flow rate was least frequently affected (24%). (3) It was suggested that exocrine dysfunction in chronic alcoholics is reversible in an early stage and that sequence of events with advancement of the stage is hypersecretion, hyperconcentration of protein, normalization of water secretion with a decrease in lipase secretion and maximal bicarbonate concentration, a decrease in amylase and chymotrypsinogen output, and finally a decrease in flow rate.

Adult↗
PubMed1979

The control of phosphoprotein phosphatase by the second-site phosphorylation of a substrate. Studies with H2B histone as model substrate.

The phosphorylation of Ser-32, in addition to Ser-36 of H2B histone, stimulated the rate of Pi release from Ser-36 by the small form (Mr 31 000) of pig heart phosphoprotein phosphatase both in the absence and presence of 50 mM magnesium acetate. By phosphorylation at Ser-32, the Km value for Ser-36 phosphate in H2B histone was increased from 0.38 microM to 1.16 microM in the absence of magnesium acetate, but not significantly changed (from 37.4 microM to 26.2 microM) in the presence of magnesium acetate. With the large form (Mr 224000) of the phosphoprotein phosphatase, however, the phosphorylation at Ser-32 suppressed the rate of Pi release from Ser-36 both in the absence and presence of magnesium acetate. The Km value of the large form for Ser-36 phosphatase in H2B histone was nevertheless increased by phosphorylation at Ser-32, from 1.2 microM to 5.3 microM in the presence of magnesium acetate, but not changed (from 0.26 microM to 0.23 microM) in the absence of magnesium acetate.

Animals↗
PubMed1979

Lateral eye movement while eyes are closed.

The present study was designed (1) to clarify whether lateral eye movements appear when eyes are closed as well as when they are open and (2) to examine some possible factors which may affect the phenomenon. Horizontal eye movements of 8 males and 8 females during reflection were recorded by means of electro-oculography. All the subjects showed fewer lateral eye movements in eyes-closed condition than in eyes-open condition, and neither the consistency of direction nor the effect of question types was replicated. These facts cannot be explained by the hemispheric activation hypothesis.

Dominance, Cerebral↗
PubMed1979

Chenodeoxycholic acid-induced diarrhea in rats: effects of atropine and codeine.

Orally administered chenodeoxycholic acid (300 mg/kg) produced diarrhea and accumulation of gastro-intestinal fluid in rats. The fluid in the stomach and small intestine remained accumulated even after the accumulated colonic fluid and the diarrheal excretion decreased. When instilled into an intestinal closed-loop, chenodeoxycholic acid caused a marked inhibition of fluid absorption in the colon and jejunum but less effect in the ileum. On the contrary, an intravenous administration of chenodeoxycholic acid caused neither diarrhea nor impairment of colonic absorption of fluid. Atropine and codeine (10 mg/kg s.c.) blocked or at least delayed the diarrhea produced by oral administration of chenodeoxycholic acid. The antidiarrheal activity of codeine was found to be more potent and longer-lasting than that of atropine. Both drugs delayed the passage of chenodeoxycholic acid containing gastric fluid into the duodenum, but neither of them prevented chenodeoxycholic acid-induced jejunal secretion of fluid and electrolytes. These results indicate that the diarrheal excretion by chenodeoxycholic acid was ascribable to the impairment of fluid absorption in the colonic mucosa and partly to the activation of gastro-intestinal propulsive motility.

Analgesia↗
PubMed1979

Separation of normal paraffins and evaluation of petroleum contamination in foods.

A method for separating n-paraffins from petroleum hydrocarbons in foods was developed. The method consists of 5 initial steps: digestion of sample with alkali, silica gel column chromatography, molecular sieve adsorption, destruction of the sieve with HCl, and oxidation with KMnO4. Recoveries of n-paraffins added to 55 g oyster at a level of 0.36 ppm ranged from 80% for normal pentadecane to 100% for n-paraffins over 18 carbon atoms. This method also facilitated the analysis of iso-paraffins such as pristane (2,6,10,14-tetramethylpentadecane) and phytane (2,6,10,14-tetramethylhexadecane), and other hydrocarbons, which are thought to be good marker compounds for the estimation of petroleum pollution.

Environmental Pollutants↗
PubMed1978

Effects of polyamine hydrochlorides and salts on phosphoprotein phosphatase.

Polyamine hydrochlorides, NaCl and magnesium acetate stimulated the enzymatic dephosphorylation of phosphorylated H2B histone by two forms (large form, mol. wt. 250 000; small form, mol. wt. 30 000) of a pig heart phosphoprotein phosphatase (phosphoprotein phosphohydrolase, EC 3.1.3.16). These ionic compounds stimulated the large form of the enzyme 5--9-fold but stimulated the small form of theenzyme only 2-fold. With phosphorylated H2B histone as substrate, these effectors caused an increase in both Km and V values of the two forms of the enzyme. On the other hand, when a tryptic phosphodecapeptide derived from phosphorylated H2B histone was used as substrate, these effectors were always inhibitory apparently non-competitively with respect to the substrate. Using phosphorylated H1 histone as substrate, these effectors stimulated the large form of the enzyme 2-fold but inhibited the small form. With phosphorylase a as substrate, the reactions were also inhibited by these effectors irrespective of the enzyme employed. With respect to phosphorylase a, this inhibition was apparently of a competitive type for the large form and a non-competitive type for the small form of the enzyme.

Animals↗
PubMed1978

Comparison of two forms of pig heart phosphoprotein phosphatase.

A phosphoprotein phosphatase (phosphoprotein phosphohydrolase, EC 3.1.3.16) was partially purified from pig heart using as substrate H2B histone which had been phosphorylated at Ser-32 and Ser-36 by adenosine 3',5'-monophosphate-dependent protein kinase (EC 2.7.1.37). The enzyme had a molecular weight of approx. 250 000 and was converted to a smaller form with a molecular weight of approx. 30 000 upon treatment with ethanol. Phosphorylase alpha (EC 2.4.1.1) and phosphorylated H1 histone also served as substrates for both forms of the enzyme. The conversion of the large form of the enzyme to the small form decreased the phosphohistone phosphatase activity to 25-50% with a concomitant 7-fold increase in the phosphorylase alpha phosphatase activity. Ser-36 phosphate was removed 6- and 15-fold more rapidly than was Ser-32 phosphate by the large and small forms of the enzyme, respectively. Among Ser-36-containing tryptic phosphopeptides derived from phosphorylated H2B histone, Lys-Glu-Ser(P)-Tyr-Ser-Val-Tyr was the shortest phosphopeptide which was dephosphorylated at a significant reaction rate with the phosphoprotein phosphatase. The Km values for phosphorylated H2B histone and the tryptic phosphopeptide were 23.7 micron and 187.1 micron, respectively, with the large form, and 81.4 micron and 90.0 micron, respectively, with the small form of the enzyme.

Animals↗