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Biomedical subjects

Y Inada

Publications and source records attributed to Y Inada.

At least 343 records · Page 19Linked to original sources
PubMed1982

Renal effects of pinane-thromboxane A2 and indomethacin in saline volume-expanded spontaneously hypertensive rats.

In 6-week old spontaneously hypertensive rats (SHR), indomethacin (5 mg/kg i.v.) and pinane-thromboxane A2 (PTA2) (50 micrograms/kg per h i.v.) a thromboxane A2 (TXA2) antagonist as well as a TXA2 synthetase inhibitor, resulted in natriuresis accompanied by an increase in p-aminohippuric acid and inulin clearances. Indomethacin acted as an antidiuretic in 6 week Wistar-Kyoto rats (WKY). PTA2 did not alter renal functions in either 6 week WKY and 18 week SHR. Basal urinary excretion of TXB2 (UTXB2V) was greater in 6 week SHR than in 6 week WKY and 18 week SHR, and that of 6-keto-PGF1 alpha (U6-keto-PGF1 alpha V) did not differ among these strains. Thus, U6-keto-PGF1 alpha V/UTXB2V was lower in the 6 week SHR. Basal urinary excretion of PGE (UPGEV) was much greater in 18 week SHR than in the 2 other groups. In the 6 week SHR, PTA2 decreased UTXB2V and increased U6-keto-PGF1 alpha V without affecting UPGEV, and indomethacin reduced UTXB2V more markedly than did U6-keto-PGF1 alpha V and UPGEV. Thus, both PTA2 and indomethacin increased U6-keto-PGF1 alpha V/UTXB2V in the 6 week SHR. These findings indicate that a disequilibrium in the biosynthesis of vasoconstrictive TXA2 and of vasodilator PGI2 may be involved in water and sodium retention in SHR during the developmental phase of hypertension.

Animals↗
PubMed1982

Physicochemical properties and states of sulfhydryl groups of uricase from Candida utilis.

Highly purified uricase [urate: oxygen oxidoreductase, EC 1.7.3.3] was obtained from Candida utilis by affinity chromatography with xanthine-agarose conjugate followed by chromatography with Sephadex G-200 in the presence of dithiothreitol. The uricase molecule had a molecular weight of 120,000 and was composed of four identical subunits with a molecular weight of 30,000. The amino acid composition was determined and the N-terminal amino acid was identified as methionine. Other physiochemical properties obtained were as follows; isoelectric point (5,6), alpha-helix content (12%; b0 = -76 +/- 15 degree), specific activity (25.8 units/mg protein) and Km value (1.0 x 10(-5) M) for uric acid at pH 8.5 and 25 degree C. The uricase preparation did not contain detectable amounts of the following metals; Fe, Cu, Mg, Mn, Co, Ni, Zn, and Cd. There were three cysteine residues in the subunit molecule and these were classified into two types by a chemical modification study; one is accessible to a reagent and the remaining two become accessible only after denaturation. The former may be located in the vicinity of the active center of the molecule, although it does not participate directly in the catalysis.

Amino Acids↗
PubMed1982

Studies on immune adherence (C3b) receptor activity of human erythrocytes: relationship between receptor activity and presence of immune complexes in serum.

Human erythrocytes (E) have surface receptors for the third component of complement (C3b-IA receptors) which mediate immune adherence haemagglutination (IAHA). We have observed that E from patients with systemic lupus erythematosus had imparied or defective C3b receptor (C3b-R) activity when circulating immune complexes (CIC) were found in serum. This phenomenon has been investigated by a newly developed method involving competitive inhibition of IAHA in patients with immune complex diseases. IAHA involving sheep E coated with antibody and complement (EAC), and indicator human E was inhibited by lysates of E with normal C3b-R activity from healthy donors and a monkey. In contrast, the lysates of E from 95% of patients bearing CIC did not inhibit IAHA, which indicated such E had defective or impaired C3b-R activity. This phenomenon was supported by control studies in which IAHA was not inhibited by lysates of E with absent, inactivated or occupied C3b-R. In those patients, in whom CIC disappeared during immunosuppressive therapy, C3b-R activity slowly returned to normal levels. Moreover, it was observed that C3b-R activity of patients' E decreased with the reappearance of CIC during exacerbations of disease. These observations suggest that CIC are carried in vivo by the C3b-R of E as well as those of the mononuclear phagocyte system, and that the E C3b-R may also contribute to the clearance of CIC.

Animals↗
PubMed1982

Increased antitumor activity of Escherichia coli. L-asparaginase by modification with monomethoxypolyethylene glycol.

Escherichia coli L-asparaginase modified with monomethoxypolyethylene glycol, which has no ability to bind to the antibody and almost no immunogenicity, had a longer plasma half-life (32.9+/-2.5 hr) in normal mice than the native enzyme (3.35 +/- 0.45 hr). Preimmunization of mice with the native enzyme greatly shortened the plasma half-life of the native L-asparaginase (less than 0.1 hr) but did not change that of the modified L-asparaginase (32.2 +/- 2.1 hr). Treatment of mice bearing asparaginase-sensitive Gardner lymphoma (6C3HED) with L-asparaginases at various doses showed that the modified enzyme had a greater therapeutic effect than the native enzyme. In addition, preimmunization with the native enzyme prevented the antitumor activity of the native enzyme but did not affect the therapeutic efficacy of the modified L-asparaginase against the lymphoma.

Animals↗