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Biomedical subjects

M Miyamoto

Publications and source records attributed to M Miyamoto.

At least 631 records · Page 35Linked to original sources

Change of oxygen affinity of hemoglobin in different conditions of blood preservation.

Changes of oxygen affinity of hemoglobin were studied in blood preserved in different conditions. Changes in hemoglobin function were least in CPD blood in plastic bags, and more extensive in ACD blood in plastic bags, ACD packed red blood cells in plastic bags and ACD blood in glass bottles, respectively. These decreases are consistent with the changes of organic phosphates levels during storage found in earlier studies. When old erythrocytes were incubated with inosine, pyruvate and phosphate, defective oxygen transport function was completely restored even after 7 weeks storage in ACD.

Blood Preservation↗

Mesolimbic involvement in the locomotor stimulant action of thyrotropin-releasing hormone (TRH) in rats.

Thyrotropin-releasing hormone (TRH) injected i.p. in doses of 5 mg/kg and higher had a strong locomotor stimulant action with development of frequent rearing, mild sniffing, grooming, preening and other excitatory behaviours. The locomotor stimulation was also produced by bilateral injection of TRH and dopamine (DA) into the nucleus accumbens but not by bilateral injection of these substances into the caudate nucleus. Unilateral intracaudate injection of TRH provoked no behavioural changes in contrast to a distinct circling response to similarly injected DA. Either i.p. or bilateral intra-accumbens injection of haloperidol or pimozide on low doses effectively blocked the locomotor stimulant action of TRH. These results indicate that the DA system in the nucleus accumbens may be of importance in mediation of the locomotor stimulant action of TRH. Differential affinity of TRH to the two DA systems, the mesolimbic and nigrostriatal DA systems is also suggested.

Animals↗

[High pressure liquid chromatography of corticosteroids: I. Preliminary report of the determinations of plasma corticosterone by HPLC combined with radioimmunoassay (author's transl)].

The analysis of corticosteroids (CDS) was preliminarily investigated using a DU PONT 830 High Pressure Liquid Chromatography (HPLC) equipped with a UV detector and a Permaphase column ETH. 1) Firstly, the best condition for the separation of mixed CS was investigated. In a linear gradient elution, ten authentic steroids, varying greatly in polarity (including native CS such as DOC, Corticosterone and Cortisol) were sharply separated in about 20 minutes. Recovery of the steroid injected into the column was 96 approximately 100%. 2) Standard CS added to the chloroform extracts from plasma or urine were also clearly separated in the same condition as above. In the experiment using predonisolone and estrone-propionate in different doses, the synthetic steroids were quantitatively separated, giving a linear calibration curve. 3) Sensitivity of the steroid determination was ng order photochemically in a plot study, but the method, using a UV detector, was not sufficient to apply to small amount of samples extracted with choloroform. To solve this problem, radioimmunoassay was applied to the eluate containing biological steroid, which was roughly separated using the synthetic steroid marker. As for the determination of plasma corticosterone using this method of HPLC combined with radioimmunoassay, the results were satisfactory for practical use; the mean based values and SD of 10 normal controls were 0.4+/-0.2 microgram/100ml for corticosterone, and they showed 4 to 5-fold increases to 250 microgram of synthetic ACTH injection.

Adrenal Cortex Hormones↗