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Biomedical subjects

H Takiguchi

Publications and source records attributed to H Takiguchi.

At least 91 records · Page 5Linked to original sources
PubMed1983

Effect of prostaglandin A2 on Na+-K+-ATPase in basolateral plasma membrane of rat intestine in vitro inhibition of activation of K+-dependent p-nitrophenylphosphatase by Na+ and ATP.

1. The activation of K+-dependent p-nitrophenylphosphatase (EC 3.6.1.7) by both Na+ and ATP in rat intestinal basolateral plasma membrane is inhibited by prostaglandin A2. 2. The drug's inhibition of the activation of the enzyme by both Na+ and ATP is due to a decrease in the affinity of the enzyme for Na+ and in the Vmax of the enzyme. 3. The Ki values for this drug for Na+ and ATP in the activation of the enzyme were 45 and 70 microM, respectively.

4-Nitrophenylphosphatase↗
PubMed1983

Vitamin D-mediated decrease of Ca2+-pump activity in the rat parotid gland.

In vitro activities of Ca2+-ATPase and 45Ca2+ uptake in microsomes, which were prepared from vitamin D-deficient rat parotid glands, were decreased in parallel by the oral administration of vitamin D3 as compared with those of control animals (r = 0.83). In vivo 45Ca2+ uptake in the parotid glands of vitamin D-deficient rats was also decreased by the oral administration of vitamin D3.

Animals↗
PubMed1982

Influence of thyroid hormone on (Na+ + K+)-dependent adenosine triphosphatase activity in rat submandibular glands.

Surgical thyroidectomy decreased (Na+ + K+)-dependent adenosine triphosphatase (Na-K-ATPase) activity in rat submandibular glands. Three successive doses of triiodothyronine (100 microgram/100 g of body wt) to euthyroid and hypothyroid rats produced 24 and 23 per cent increase in the enzyme activity, compared to control values. When hypothyroid rats were given smaller doses of triiodothyronine (4 microgram/100 g body wt every 48 h) for 27 days, Na-K-ATPase activity increased 40 per cent over the corresponding values in the control hypothyroid rats. Thus, thyroid hormone acts on rat submandibular glands to increase the Na-K-ATPase activity of that target tissue.

Animals↗
PubMed1982

Some characteristics of cytosol binding protein for 1 alpha,25-dihydroxycholecalciferol, 24R,25-dihydroxycholecalciferol and 25-hydroxycholecalciferol in rat parotid gland.

1. 1 alpha,25-dihydroxycholecalciferol (1,25-(OH)2VD3), 24R,25-dihydroxycholecalciferol (24,25-(OH)2VD3) and 25-hydroxycholecalciferol (25-OHVD3) binding proteins were existed in cytosol of rat parotid gland. 2. The dissociation constants of binding proteins for 1,25-(OH)2VD3, 24,25-(OH)2VD3 and 25-OHVD3 were 3.15 x 10(-9), 5.05 x 10(-9) and 6.60 x 10(9) M, respectively. 3. The mol wt and the isoelectric point (pI) of binding proteins for 1,25-(OH)2VD3, 24,25-(OH)2VD3, 24,25-(OH)2VD3 and 25-OHVD3 were the same to each other (with mol wt of 155,000 and pI of 4.87). 4. The binding specificity of 1,25-(OH)2VD3 binding protein was similar to that of 24,25-(OH)2VD3 and 25-OHVD3 binding protein. 5. The extent of loss of binding activity for 1,25-(OH)2VD3 by pronase and trypsin was much greater than that of binding activity for 24,25-(OH)2VD3 and 25-OHVD3.

Animals↗
PubMed1982

Effect of indomethacin on Ca2+-stimulated adenosine triphosphatase in the synaptic vesicles of rat brain in vitro.

1. Indomethacin inhibits calcium-stimulated adenosine triphosphatase (Ca2+-ATPase), calcium, magnesium-stimulated adenosine triphosphatase (Ca2+,Mg2+-ATPase) and magnesium-stimulated adenosine triphosphatase (Mg2+-ATPase) activities in rat brain synaptic vesicles in vitro. 2. The Ca2+-ATPase activity is most strongly affected by this drug all of the activities of ATPases tested. 3. The decrease of Ca2+-ATPase activity by addition of indomethacin is due to a decrease of Vmax. 4. The Ki values for this drug for ATP and Ca2+ in Ca2+-ATPase were 1.13 mM and 0.68 mM, respectively.

Adenosine Triphosphate↗
PubMed1982

Inhibitory effect of prostaglandin A2 on Na+-K+-ATPase activity in synaptic plasma membrane of rat brain in vitro.

1. The Na+-K+-ATPase activity in the synaptic plasma membrane of rat brain was inhibited by PGA2 in vitro. 2. PGA2 concentration required for 50% inhibition was 8.91 x 10(-5) M. 3. Inhibition mode of PGA2 for both ATP and Mg2+ was uncompetitive type. 4. PGA2 was competitive and noncompetitive with Na+ and K+, respectively. 5. The Ki values for PGA2 inhibition for ATP. Na+, K+ and Mg2+ were 6.0 x 10(-5), 2.7 x 10(-5), 10.8 x 10(-5) and 0.6 x 10(-5) M, respectively.

Animals↗
PubMed1982

Inhibitory characteristics of indomethacin on the activation of K+-dependent p-nitrophenylphosphatase by both Na+ and ATP in vitro.

1. The activation of K+-NPPase by both Na+ and ATP was inhibited by indomethacin in vitro. 2. Indomethacin concentration required for 50% inhibition was 6.25 X 10(-4) M. 3. Inhibition manners of indomethacin for Na+ and ATP were competitive type and noncompetitive type, respectively. 4. The Ki values for indomethacin for Na+ and ATP were 1.4 X 10(-4) M and 8.8 X 10(-4) M, respectively. 5. The inhibitory effect of indomethacin was reversible.

4-Nitrophenylphosphatase↗
PubMed1982

Mode of inhibition of activity of Na+-K+-stimulated adenosine triphosphatase by indomethacin.

1. The activity of the overall Na+-K+-ATPase reaction was inhibited by indomethacin in vitro. 2. The K+-NPPase activity was also inhibited by indomethacin. 3. The activity of Na+-dependent phosphorylation of Na+-K+-ATPase was activated by indomethacin. 4. Indomethacin required for 50% inhibition of K+-NPPase activity was 0.4 mM. 5. Inhibition mode of indomethacin for both the substrate and K+ in K+-NPPase reaction was competitive type. 6. The Ki values for indomethacin for the substrate and K+ in K+-NPPase reaction were 0.4 and 0.24 mM, respectively. 7. Inhibitory effect of indomethacin on K+-NPPase was reversible.

4-Nitrophenylphosphatase↗