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Biomedical subjects

Y Inada

Publications and source records attributed to Y Inada.

At least 361 records · Page 20Linked to original sources
PubMed1981

Enhanced thromboxane A2 biosynthesis in the kidney of spontaneously hypertensive rats during development of hypertension.

Arachidonic acid (AA)-induced pressor response and production of thromboxane YXB2, the stable metabolite of TXA2, prostaglandin (PG)-like substance (PLS) and 6-keto-PGF1 alpha the stable metabolite of prostacyclin (PGIs), were studied using isolated, perfused kidneys of 6- and 18-week old spontaneously hypertensive rats (SHR), Wistar-Kyoto rats (WKY), two-kidney, one clip hypertensive rats (RHR) and DOCA/salt hypertensive rats (DOCA/salt HR). The AA-induced pressor response and release of TXB2 were highest in the 6-week old SHR, whereas, the release of PLS and 6-keto-PGF 1 alpha was marked in the 18-wek old SHR and the established hypertensive stages of both RHR and DOCA/salt HR. In the kidneys of SHR and WKy, exogenous TXA2 induced a severe vasoconstriction and there was a positive correlation between the AA-induced pressor response and the release of TXB2 or PLS. Thus, the initiation of hypertension in SHR may follow an accelerated synthesis of TXA2 against PGI2 in response to stimuli which induce a release of AA.

Animals↗
PubMed1981

Suppression of IgE antibody response by the fatty acid-modified antigen.

Ovalbumin (OA) of hens was chemically coupled with fatty acids (lauric acid, myristic acid, palmitic acid and stearic acid). These hydrophobically modified antigens were unable to react with mouse antiserum against native OA and were incapable of eliciting primary and secondary anti-OA antibody responses in BALB/c mice. Preadministration of these modified antigens, especially of palmitoyl OA (OA-pal), suppressed both primary and secondary anti-OA IgE antibody responses without affecting IgG antibody production. Administration of OA-pal after the primary immunization resulted in a rapid decrease of the ongoing anti-OA IgE antibody production and inhibited the anamnestic anti-OA IgE antibody response upon subsequent immunization with OA. The passive transfer of spleen cells from OA-pal-treated animals with OA-primed spleen cells suppressed the adoptive secondary anti-OA IgE antibody response in irradiated recipients. The suppressive effect was abrogated by treatment with an anti-T-cell antiserum indicating that suppressor T cells were primed by administration of hydrophobically modified antigens.

Animals↗
PubMed1981

Improved modification of yeast uricase with polyethylene glycol, accompanied with nonimmunoreactivity towards anti-uricase serum and high enzymic activity.

The highly purified uricase from Candida utilis was modified with 2,4-bis(O-methoxypolyethylene glycol)-6-chloro-s-triazine (activated PEG2), which was synthesized from monomethoxypolyethylene glycol (MW 5,000) and cyanuric chloride. Modification of approximately 36 out of the total 98 amino groups in the uricase molecule led to the complete loss of the binding ability towards antiuricase serum from rabbit with the retention of high enzymic activity (45% of native uricase). The modified uricale cleared more slowly from the plasma of mice compared with native uricase.

Animals↗
PubMed1981

Reduction in immunogenicity and clearance rate of Escherichia coli L-asparaginase by modification with monomethoxypolyethylene glycol.

Escherichia coli L-asparaginase was modified with monomethoxypolyethylene glycol using cyanuric chloride as a coupler. The modified enzyme did not cross-react with anti-L-asparaginase antibody in precipitin reaction, but retained some catalytic activity (8% of the original activity). It has the same Km value for L-asparagine and the same optimal pH as the native enzyme. The immunogenicity of the modified enzyme was substantially reduced because mouse antiserum to it showed no significant increase in hemagglutinin titer of L-asparaginase-coated sheep red blood cells. After a single i.p. injection of the modified enzyme (80 I.U./kg) into rats, enzyme activity was detected in the serum within 30 min and persisted for over 3 weeks. Concomitant depletion of serum L-asparagine persisted for more than 3 weeks. On the other hand, the active enzyme was rapidly cleared from the serum. The half-lives of the modified and native enzymes were calculated to be 56 and 2.9 hr, respectively. This modified L-asparaginase may be much more useful than the native enzyme for the clinical treatments of tumors because of its reduced immunogenicity.

Animals↗