Search PubMed⌕ Search

Biomedical subjects

Y Inada

Publications and source records attributed to Y Inada.

At least 217 records · Page 12Linked to original sources

Cooperativity between platelet-activating factor and collagen in platelet aggregation.

Cell lysate obtained from cultured vascular endothelial cells contained a substance which induced platelet aggregation. This substance was identified as a phospholipid, 1-O-alkyl-2-acetyl-sn-glycero-3-phosphocholine (platelet-activating factor; PAF), by thin-layer chromatography, phospholipase A2 digestion, inhibition by a specific antagonist, CV-3988, and agonist-specific refractory state. It was further found that PAF and collagen together induced extensive aggregation of platelets even with the concentrations by which each agonist alone could not induce aggregation of platelets at all.

Animals↗

Purification of atrial natriuretic peptide receptor from bovine lung. Evidence for a disulfide-linked subunit structure.

The receptor for atrial natriuretic peptide (ANP) was purified to apparent homogeneity from bovine lung by a combination of detergent extraction, ammonium sulfate precipitation, and affinity chromatography on ANP-Affi-Gel 10. The Mr of the purified receptor is about 140,000 as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. After reduction, the protein migrated as a single band with an Mr near 70,000. NH2-terminal sequence analysis of the purified material revealed only one sequence, indicating that the ANP receptor is composed of two probably identical subunits held together by disulfide bond(s), although it remains possible that one of the subunits is blocked at the NH2 terminus. Antibody was produced to the nonreduced Mr = 140,000 species and shown to interact with detergent-solubilized forms of the lung and kidney ANP receptor.

Animals↗

Analysis of distribution of receptors among platelets by flow cytometry.

We have investigated the binding of fluorescein isothiocyanate (FITC)-labeled fibrinogen to platelets using a fluorescence spectrophotometer and a flow cytometer. The amount of fibrinogen bound by stimulation of adenosine diphosphate (ADP) and 5-hydroxytryptamine (5HT) increased in a dose-dependent manner. Stimulation of one agonist was independent of that of another agonist. Fibrinogen could bind to platelets in response to ADP, regardless of whether they were desensitized by 5HT, and vice versa. It was found by flow cytometric analysis that individual platelets responded uniformly to both ADP and 5HT, indicating that individual platelets have receptors for both ADP and 5HT on their surfaces.

Adenosine Diphosphate↗

Magnetic lipase active in organic solvents.

Magnetic lipase (magnetite particles coated with polyethylene glycol-modified lipase) was prepared in two steps: Lipase was coupled with 2,4-bis(O-methoxypolyethylene glycol)-6-chloro-s-triazine, activated PEG2, to obtain polyethylene glycol-modified lipase, PEG-lipase. The PEG-lipase was added to the solution of ferrous (Fe2+)- and ferric(Fe3+)-ions with the pH value adjusted to 8.0-8.5 to obtain magnetic lipase. The magnetic lipase was dispersed in organic solvents such as benzene and 1,1,1-trichloroethane with the particle size of 120 +/- 60 nm. The colloidal solution was very stable and no aggregation occurred even after 5 days. A high enzymic activity (11.6 mumol/min/mg protein) for lauryl laurate synthesis was observed in 1,1,1-trichloroethane. The magnetic lipase was readily recovered from the organic solvents in a magnetic field of 6000 Oe without loss of the enzymic activity.

Benzene↗

Venom from southern copperhead snake (Agkistrodon contortrix contortrix). I. Characterization of a protease that preferentially releases fibrinopeptide B.

Using gel permeation chromatography with high performance liquid chromatograph (HPLC), a highly purified preparation of a protease has been obtained from the venom of the southern copperhead snake (Agkistrodon contortrix contortrix). Both gel permeation chromatography with HPLC and sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed that it had an apparent Mr of 60,000-64,000. It consisted of a single polypeptide chain. The activity was inhibited by dithiothreitol. It neither induced platelet aggregation nor activated plasma factor XIII. It cleaved fibrinopeptide B at a rate much faster than fibrinopeptide A from fibrinogen. This specificity was steadily lowered when the incubation temperature was elevated from 0 degrees C to 45 degrees C. Fibrinopeptides were released only at neutral pH.

Animals↗

An attempt to determine lipid peroxides with polyethylene glycol-modified hemin.

Hemin, having two carboxyl groups, was coupled with alpha-(3-aminopropyl)-omega-methoxypoly(oxyethylene) through the acid-amide bond formed with carbodiimide. The modified hemin catalyzed the peroxidase reaction in 1,1,1-trichloroethane using benzoyl peroxide or peroxides in unsaturated fatty acids as the hydrogen acceptor and leuco crystal violet as the hydrogen donor. A basic study on quantitative microanalysis of the lipid peroxides was attempted.

Heme↗