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Biomedical subjects

M Tanabe

Publications and source records attributed to M Tanabe.

At least 397 records · Page 22Linked to original sources

[103Ru for tumor scanning--a comparative study on tissue distributions of 103Ru-chloride and 103Ru-citrate in tumor-bearing animals (author's transl)].

Biological distribution of 103Ru in mice bearing Ehlrich's solid tumor and rats bearing AH-130 solid tumor were studied with two compounds of 103Ru, the chloride and citrate. The radioactivity of 103Ru-chloride showed slower excretion and higher tumor concentration than that of citrate. The tumor-to-muscle ratios of chloride were always higher, but the tumor-to-blood ratios were always lower than those of citrate. No significant difference was founds between 103Ru-chloride and citrate as tumor scanning agents.

Animals↗

Effects of a 2-substituted adenosine derivative, 2-(p-methoxyphenyl)-adenosine (CV-1674) on coronary and cardiohemodynamics, and myocardial energetics.

In dogs, intracoronary doses of CV-1674, adenosine ( ADS) and 2-Cl-ADS for doubling coronary flow were estimated as 5.0, 2.0 and 0.4 microgram/dog, and i.v. doses 31, 71 and 2.5 microgram/kg, respectively. ADS and 2-Cl-ADS decreased, while CV-1674 increased LV dp/dt. Intravenous infusion (30 min) of CV-1674 (10 microgram/kg per min) and ADS (700 microgram/kg per min) decreased coronary resistance to approximately the same extent. Decreases in blood pressure, total peripheral resistance and myocardial O2 concumption with ADS were more prominent than those with CV-1674. ADS produced a marked bradycardia that was not evident with CV-1674. Neither agent had a significant influence on myocardial efficiency. In guinea pig atria, ADS and 2-Cl-ADS exerted negative effects while those with CV-1674 were positive inotropic and chronotropic. In cats, intraduodenal ADS (10 mg/kg) produced no effects on cardiohemodynamic parameters. CV-1674 (250 and 500 microgram/kg) increased myocardial tissue blood flow (MBF) with a slight hypotension in a dose-dependent manner, whereas 2-Cl-ADS (100, 250 and 500 microgram/kg) increased MBF only with the highest dose concomitantly with marked hypotension and bradycardia. These results suggest that CV-1674 induces selective coronary vasodilation with less depression on cardiohemodynamics, and is relatively well absorbed from the intestinal tract. The pharmacological profile of the compound, therefore, differs from that of ADS and 2-Cl-ADS.

Adenosine↗

Studies on ferrous ion-induced lipid peroxidation of rat liver mitochondria. II. Relationship to incubation temperature.

Ferrous ion-induced lipid peroxidation in rat liver mitochondria has a lag in the induction period. The characteristics of the lag were investigated under various conditions. This lag period lengthened proportionally to increased temperature (4 degrees approximately 37 degrees C). In the presence of inorganic phosphate the lag period lengthened, reaching a maximum at about 20 degrees C, and then shortened with increased temperatute. Elongated lag periods were shown in heat-treated or protein digested mitochondria. Shortened lag periods were shown in snake venom-treated mitochondria. On the other hand, almost no lag was observed in the peroxidation of the lipid extracted from mitochondria. The lag period also varied with incubation temperature. The results suggested that certain factors, which determined lag of the induction period in membrane lipid peroxidation associate with reaction-temperature and the lipo-protein structure in mitochondrial membranes.

Animals↗

Tissue distributions of 97Ru and 103Ru in subcutaneous tumor of rodents.

Mice bearing Ehrlich tumor were administered 97Ru-chloride or 103Ru-chloride intravenously. Examinations of various tissues indicated similar distributions by the two radionuclides. The levels were higher in the lung, liver and kidney than in the tumor tissue. Rats bearing AH-130 tumor were administered 103Ru-chloride intravenously. The 103Ru distribution in rats was highest in the spleen, followed by the liver and kidney; however, the radioactive distribution in the tumor tissue exceeded the muscle level by about 5-fold. Tumors were delineated in rats by scintigraphy. The findings indicate that ruthenium radionuclides may be a useful clinical agent in the delineation of some types of tumors. Ruthenium-97 would be favored in possible clinical usage due to its shorter physical half-life and lower levels of gamma energy.

Animals↗