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Biomedical subjects

K Sumikawa

Publications and source records attributed to K Sumikawa.

At least 181 records · Page 10Linked to original sources
PubMed1981

Further investigations on a novel gamma-glutamyl transpeptidase in human renal carcinoma.

The enzymic and immunological properties of a novel gamma-glutamyl transpeptidase found in human renal carcinoma tissues were investigated further in comparison with those of the normal kidney enzyme. On isoelectric focusing, the novel gamma-glutamyl transpeptidase separated into two main forms, having pI values below 3.6, while the normal kidney enzyme separated into multi-molecular forms with pI values of 4.0-5.0. Neuraminidase treatment diminished the difference between these two enzymes, the products of the novel enzyme and the normal kidney having pI values of 5.4 and 5.6, respectively. The percentages of the total activity of the novel gamma-glutamyl transpeptidase binding with Con A before and after neuraminidase treatment were about 40% and 80%, respectively, while the corresponding percentages of the activity of the normal kidney enzyme were less that 10% and about 25%, respectively. The novel gamma-glutamyl transpeptidase was immunologically identical with the normal kidney enzyme in the activity inhibition test and the double diffusion test. The present data suggest that the novel gamma-glutamyl transpeptidase has the same antigen site as the normal kidney enzyme, but differs from the latter at least in its sialic acid content and in some other carbohydrate moieties.

Carcinoma↗
PubMed1981

gamma-Glutamyltransferase from human hepatoma tissue in comparison with normal liver enzyme.

gamma-Glutamyltransferase was solubilized from human hepatoma tissues by bromelain treatment, and some of its properties were compared with those of the normal adult liver enzyme. An electrophoretic study showed a slightly different mobility between the two enzymes before and after neuraminidase treatment. The hepatoma tissue enzyme was distinguished from the normal liver enzyme by decreased affinity to Con A. However, the enzymes from the two sources were found to be very similar or identical with respect to molecular weight, Michaelis constant, pH optimum, thermostability, effect of various L-amino acids as acceptors, behavior to divalent cations or ethylenediaminetetraacetate, inhibition by urea or sodium dodecyl sulfate, and immunological properties. These results suggest that the hepatoma tissue gamma-glutamyltransferase is largely due to altered glycosylation of this glycoprotein in hepatoma cells.

Carcinoma, Hepatocellular↗
PubMed1981

Quinuclidinyl benzilate binding in house fly heads and rat brain.

House fly heads contain a binding site for 3-quinuclidinyl benzilate (QNB) that is quite similar in pharmacology to the muscarinic acetylcholine receptor of vertebrate tissues. The house fly site binds [3H]QNB reversibly with a Kd of 260 pM and Bmax of 1 pmol/g of heads from direct binding measurements. The Kd calculated from the ratio of the dissociation rate constant (2 x 10(-4)sec-1) to the association rate constant (2.5 x 10(6) M-1sec-1) was 80 pM. The house fly site binds (-)quinuclidinyl benzilate preferentially, as do classic muscarinic receptors. The binding is also sensitive to other muscarinic antagonists and agonists. Nicotinic and other drugs are no more effective on the house fly site than they are on the rat brain muscarinic receptor itself. These binding studies suggest that the house fly QNB binding site is a muscarinic receptor.

Animals↗
PubMed1981

Gamma-glutamyl transpeptidase in a newly established cell line from human renal carcinoma, OUR-10.

A newly established cell line, OUR-10, from human renal carcinoma seems to have the same gamma-glutamyl transpeptidase as the novel one which was found recently in renal carcinoma tissue; the enzymic properties such as electrophoretic mobility, Km value, molecular weight, thermostability, the effects of urea, sodium dodecyl sulfate and sulfhydryl reagents, the effects of amino acids, cations and EDTA, and the binding behavior to a concanavalin A-Sepharose column were the same as those of the novel gamma-glutamyl transpeptidase found in renal carcinoma tissue. The immunological properties of the gamma-glutamyl transpeptidase (GGTP) of OUR-10 examined by inhibition tests and tests of cross-reactivity with anti-normal kidney GGTP antibody were also the same as those of the novel gamma-glutamyl transpeptidase. These results may mean that the novel gamma-glutamyl transpeptidase originates from the cancer cells, and can be used as a marker for identification of this cell line, OUR-10.

Adult↗
PubMed1980

Effects of cyclopropane on catecholamine release from bovine adrenal medulla.

The direct effects of cyclopropane on both adrenal medullary release of catecholamines and release of catecholamines from isolated chromaffin granules were examined. Cyclopropane had no effect on the spontaneous release of catecholamines from perfused bovine adrenals, while it reversibly inhibited carbachol-induced release of catecholamines in a dose-dependent manner. At 20 per cent cyclopropane, catecholamine release was reduced to 52 per cent of control. Cyclopropane exerted no action on spontaneous release or Mg++-ATP-dependent release of catecholamines from isolated chromaffin granules. Thus, the authors conclude that the direct action of cyclopropane on the adrenal medullary release of catecholamines is inhibitory, and that chromaffin granules are not the site of action of this anesthetic.

Adenosine Triphosphate↗
PubMed1980

Catecholamine uptake and release in isolated chromaffin granules exposed to halothane.

The effects of halothane on the catecholamine release from chromaffin granules and the uptake of 14C-epinephrine into the granules were studied using isolated bovine adrenal medullary chromaffin granules. The granules were isolated with a Millipore filter, and were incubated for 10 min in an isotonic medium containing adenosine triphosphate (ATP)-Mg++. At halothane concentration of 0.4 mM or greater, the uptake of 14C-epinephrine into the granules was inhibited in a dose-related manner. At 0.7 mM halothane, epinephrine uptake was reduced to 56 per cent of control. The inhibition was completely reversible after removal of halothane from the medium. The inhibitory effect of halothane was not affected by high-osmolar medium. Catecholamine release from isolated chromaffin granules was enhanced by halothane at concentrations of more than 1.3 mM, but was not affected when the concentration was 0.7 mM or less. The results suggest the possiblity that halothane might alter the intracellular storage-turnover process and the subsequent release pattern of catecholamines. The possible mechanisms of this action are discussed.

Adenosine Triphosphate↗
PubMed1980

Arylamidase from human renal cancer tissue in comparison with normal kidney and placental enzymes.

Arylamidase (E.C. 3.4.11.2) was solubilized from renal cancer tissues by bromelain treatment, and its properties were compared with those of normal kidney and placental enzymes after partial purification. Their column chromatograms on TEAE-cellulose revealed a slight, but constant difference in the negative charge, namely, in normal kidney, renal cancer tissue, and placental enzymes in increasing order. An electrophoretic study on polyacrylamide gel showed comparable results. On the other hand, when treated with neuraminidase prior to electrophoresis, the renal cancer tissue and kidney enzymes came to have an identical mobility, while the placental enzyme still had a faster mobility than the others. The renal cancer tissue arylamidase was not clearly distinguished from the kidney and placental enzymes with respect to molecular weight, Michaelis constant, pH optimum, heat stability, behavior to divalent cations or chelating agents, susceptibility to urea or amino acids, inhibition by sulfhydryl agents, and immunological properties. These results suggest that renal cancer tissue and kidney enzymes are similar glycoproteins, simply different in sialic acid content, and that these two enzymes are different from the placental enzyme in the structure of the peptide portion and/or carbohydrate portions other than sialic acid residues.

Aminopeptidases↗
PubMed1979

Effects of muscle relaxants on catecholamine release from adrenal medulla.

Bovine adrenals were perfused with secretagogues in the presence or absence of muscle relaxants. On a molar basis, Dially-nor-toxiferine was as potent as tubocurarine in inhibiting the catecholamine release induced by carbachol; pancuronium was about 100 times less potent than tubocurarine, whereas gallamine and succinylcholine produced no inhibition whatsoever. KCl-induced catechoamine release was not affected by any of these compounds. Nicotine-induced catecholamine release was inhibitedby diallyl-nor-toxiferine, tubocurarine and pancuronium, but not by gallamine or succinylcholine. Muscarine failed to stimulate the adrenal medulla to release catecholamines. The results show that the inhibition of catecholamine release is based on the specific block of the nicotinic receptor, whereas gallamine and succinylcholine possess no blocking action, and that diallyl-nor-toxiferine and tubocurarine might affect clinical symptoms under conditions in which catecholamine release from the adrenal is increased by a compensatory mechanism.

Adrenal Medulla↗