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Biomedical subjects

M Matsui

Publications and source records attributed to M Matsui.

At least 487 records · Page 27Linked to original sources
PubMed1984

Effects of steroid hormones and xenobiotics on the pubertal development of UDP-glucuronosyltransferase activities towards androsterone and 4-nitrophenol in Wistar rats.

Oestradiol benzoate, testosterone propionate, progesterone, corticosterone, 3-methylcholanthrene and phenobarbital were administered to Wistar rats at the pubertal period, and their effects on hepatic UDP-glucuronosyltransferase activities were determined. Pretreatment with oestradiol benzoate had a temporary suppressive effect on androsterone UDP-glucuronosyltransferase activity in rats with the high-activity phenotype of androsterone glucuronidation. The effect was marked in 40-day-old rats, but was not found in older rats. Androsterone UDP-glucuronosyltransferase activity was induced by phenobarbital in rats with the high-activity phenotype, but not in rats with the low-activity phenotype. Foster-feeding experiments showed that breast milk did not alter the genetically determined expression of androsterone UDP-glucuronosyltransferase activity in Wistar rats. In contrast, 4-nitrophenol UDP-glucuronosyltransferase activity was not affected by steroid hormones, but was highly induced by 3-methylcholanthrene.

Androsterone↗
PubMed1984

Structure-activity relationships of nitrosamines and nitramines which stimulate UDP-glucuronosyltransferase activities in vitro.

Examination of twelve nitrosamines and seven nitramines revealed that nitramines modify UDP-glucuronosyltransferase activity in a manner similar to that of nitrosamines. Only N,N-diethyl-substituted nitrosamine and nitramine significantly stimulated transferase activity toward 2-aminophenol and 4-nitrophenol but not toward phenolphthalein and androsterone. Elongation of the alkyl chains or introduction of carboxy, hydroxy, or oxo groups into the alkyl chains did not result in stimulatory ability, and some of these compounds inhibited the transferase activity.

Aminophenols↗
PubMed1984

D-Arg2-dermorphin tetrapeptide analogs: a potent and long-lasting analgesic activity after subcutaneous administration.

To examine pharmacological properties of D-Arg2-dermorphin tetrapeptides, six tetrapeptide analogs based on the following formulas, H-Tyr-D-Arg-Phe-Gly-OX (X = H, ethyl, n-propyl), H-Tyr-D-Arg-Phe-Sar-OX (Sar = sarcosine; X = H, methyl, ethyl), were prepared. All these analogs exhibited highly potent and long-lasting analgesia as compared with that of morphine after subcutaneous administration in mice. Among analogs tested, H-Tyr-D-Arg-Phe-Sar-OH showed the highest activities, which were 21, 30 and 58 times more active than morphine in the tail pressure, tail flick and phenylbenzoquinone writhing tests, respectively, on a molar basis.

Analgesics↗
PubMed1984

Rat liver sulfotransferases: effects of gonadal hormones and other factors on enzyme activities.

Estradiol benzoate (EB), testosterone propionate (TP), progesterone (PG), corticosterone (CS), 3-methylcholanthrene (MC) and phenobarbital (PB) were administered to Wistar rats and their effects on hepatic sulfotransferase (ST) activities toward androsterone (AD) and 4-nitrophenol (NP) were determined. ST activity toward AD was increased by pretreatment with EB and PG in male rats. ST activity toward NP was increased by administration of TP and PG in females, whereas the enzyme activity was suppressed by pretreatment with EB in males. Administration of CS, MC and PB did not significantly affect ST activities toward AD and NP. These results indicate that sex difference in rat liver ST activities appears to be primarily regulated by androgenic, estrogenic and progestational hormones.

Aging↗
PubMed1984

Gas-chromatographic determination of environmental gases with the application of thermal desorption from charcoal disk.

Direct measurement of the gases adsorbed on charcoal disk was examined by the gas-chromatograph with thermal desorption devices to improve the inadequacies of the common passive monitor. Since the most satisfactory values were obtained by a preliminary experiment with toluene vapor, the experiments were done with concentrations of 20, 40 and 80 ppm, respectively to get a linear relationship between the mean adsorption per piece and the concentration of toluene. Adsorption on the charcoal disk, and its extraction by carbon disulfide without degeneration, are the necessary conditions for the measurement of gas concentration. Methanol was selected as typical from among the gases for which the common passive monitor is inapplicable. The experiment on methanol was carried out in a manner similar to that done on toluene. In conclusion, our method was found to be satisfactory for the analysis of toluene, and, if the conditions are appropriate, for methanol.

Adsorption↗
PubMed1984

Analysis and occurrence of total N-nitroso compounds in the Japanese diet.

A quantitative technique for differentiating the total N-nitrosamides from the total N-nitroso compounds has been devised. The principle of this method is based on the chemiluminescence response of a nitroso compound under different denitrosating conditions. We also examined the effect of nitrite scavengers on the stability of N-nitroso compounds and found that both ammonium sulfamate and hydrazine sulfate can be satisfactorily used for the detection of chemiluminescence response with hydrogen bromide-acetic acid reagent. A survey of the occurrence of total N-nitroso compounds, total N-nitrosamides, volatile N-nitrosamines, nitrates and nitrites in the Japanese diet has been conducted. Fairly high levels of total N-nitroso compounds were detected in salt-fermented vegetables, the highest being 2 500 micrograms/kg in hakusai-zuke (salt-fermented Chinese cabbage), followed by 253 micrograms/kg in takuan (salt-fermented radish roots). It is noteworthy that the amounts of total N-nitroso compounds in these products almost coincided with those of total N-nitrosamides, although no appreciable amounts, or only trace quantities, of volatile nitrosamines could be detected in these vegetable products.

Diet↗
PubMed1983

Stacking interaction of indole ring with thiazolium ring and effect for H-D exchange reaction of thiamin.

As part of a program to clarify the possible binding mode of tryptophan with thiamin coenzyme, the interaction between the indole and thiazolium rings has been studied by using a model compound, 2-(3,4-dimethylthiazolium-5-)ethyl indole-3-propionate, and the prominent stacking formation between both rings has been evidenced by the spectroscopic and X-ray crystallographic methods. The faster H-D exchange reaction of thiamin C2 proton observed in the presence of indole than in the lack would be resulted from the pi-pi charge-transfer interaction between the indole ring and the thiazolium ring of thiamin.

Chemical Phenomena↗