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Biomedical subjects

M Ohashi

Publications and source records attributed to M Ohashi.

At least 325 records · Page 18Linked to original sources
PubMed1988

Metabolism of diltiazem. I. Structures of new acidic and basic metabolites in rat, dog and man.

The metabolites of diltiazem in the urine of rats, dogs and man and rat bile were investigated. New metabolites including six acidic metabolites (A1-A6) and four basic metabolites (M9, MB, MC, MD) were isolated by high performance liquid chromatography and their structures were characterized by gas chromatography-mass spectrometry. Acidic metabolites A1, A2, A3, A4 and basic metabolite MD identified by comparing their properties with the synthetic compounds; (+)-(2S, 3S)-2-(4-methoxyphenyl)-3-acetoxy-4-oxo-2,3,4,5-tetrahydro-1,5- benzothiazepin-5-acetic acid (A1), 3-deacetyl-A1 (A2), O-demethyl-A1 (A3), O-demethyl-3-deacetyl-A1 (A4) and N-didemethyl-diltiazem (MD). All acidic metabolites have a CH2COOH group which may be formed by oxidative deamination of the CH2CH2N(CH3)2 group of diltiazem.

Animals↗
PubMed1988

Metabolism of diltiazem. II. Metabolic profile in rat, dog and man.

The metabolism of diltiazem was studied in male rats and dogs after intravenous administration of 14C-diltiazem.HCl or in men after oral administration of a tablet of diltiazem.HCl. The main metabolites in rat urine, in decreasing order of content, were A4, M6, M4 and M5. The unchanged drug in the urine accounted for only 0.7% of the administered drug based on radioactivity. About 81% of biliary radioactivity in rat was due to water-soluble metabolites and the remainder was mostly acidic metabolites such as A4 and A6. In dog urine, the unchanged drug was most abundant (30.6% of the radioactivity in the 6-h urine), followed by A2, A1 and M2. The main metabolites of diltiazem in rat plasma were A2 and A4, while in dog plasma, the unchanged drug and A2 were found as main components. In human urine, M4, the unchanged drug, A2, MB, MD and M2 were the major components. Acidic metabolites, A1-A4, were found also in human plasma and A2 was the main metabolite found. These results indicated that the main metabolic pathway of diltiazem was an oxidative deamination which is extensive in the rat. Other metabolic pathways recognized in this study were oxidative demethylation, deacetylation, hydroxylation of the aromatic ring and conjugation. Although direct comparison may not be appropriate because of the different routes of administration, the metabolism of diltiazem in man appears to be more similar to that in the dog than that in the rat.

Administration, Oral↗
PubMed1988

Plasma 7B2 (a novel pituitary protein) immunoreactivity concentrations in patients with various endocrine disorders.

We have measured plasma 7B2 (a novel pituitary protein)-immunoreactivity (IR) concentrations in patients with various endocrine disorders. Mean (+/- SEM) basal plasma 7B2-IR concentrations (ng/L) in patients with acromegaly (81 +/- 14.6), Cushing's disease (57.2 +/- 8.5), prolactinoma (71.4 +/- 9.5), panhypopituitarism (50.6 +/- 7.6), isolated ACTH deficiency (47.9 +/- 11.6), hyperthyroidism (57.9 +/- 6.7) and hypothyroidism (60.8 +/- 9.4) were on the same levels as those in age-matched normal subjects. However, basal plasma 7B2-IR concentrations were increased to more than 100 ng/L in 5 out of 25 patients with acromegaly (20%). Mean basal plasma 7B2-IR concentrations in patients with medullary carcinoma of the thyroid and pheochromocytoma were 293 +/- 38.1 ng/L (range: 225.7-357.4 ng/L, n = 3) and 221 +/- 82.8 ng/L (range: 48.5-527.8 ng/L, n = 5), respectively, and significantly higher than those in age-matched normal subjects (P less than 0.001). These results suggest that plasma 7B2-IR may have some diagnostic value for acromegaly and may be useful as a marker for medullary carcinoma of the thyroid and pheochromocytoma.

Acromegaly↗
PubMed1988

Small, yet steady secular gain in height and weight of school children in the city of Sendai in past 15 years.

Secular changes in height and weight of primary (6th year grade) and junior high (3rd year grade) school children in the city of Sendai during the period of 1973 to 1987 were analyzed in comparison with the counterpart changes in Miyagi prefecture and all Japan. The regression analysis revealed that there was a linear relationship between the year of examination and the measures of height and weight both in boys and girls of primary and junior high schools. The secular gain was very steady, but the annual gain was small, i.e., about one third to one sixth of the counterpart value in 1960-1964 when the secular gain was the largest. Such reduction in secular gain is apparently common throughout the country. Rohrer's and Quetlet's indices stayed essentially unchanged throughout the 15 year study period among the school children in Sendai, in Miyagi and in Japan.

Body Height↗
PubMed1987

Unique distributions of natriuretic hormones in dog brain.

We examined the regional distributions of atrial natriuretic polypeptide (ANP) and digoxin-like immunoreactivity (DLI) in dog brain, using specific radioimmunoassay. The molecular form of the dog brain ANP was similar to that of alpha-hANP, in gel filtration and reversed-phase HPLC. Distribution of ANP in dog brain differed from rat brain. A significant amount of ANP-like immunoreactivity (ANPLI) was observed in the periaqueductal grey, ventral thalamus and spinal cord, however, only a trace amount was seen in the hypothalamus. The DLI was widely distributed in the dog brain, especially with over 2 ng/g wet wt. of the immunoreactivity content in mammillary body, septum, striatal body, hypothalamus and periaqueductal grey. Different from the localizations of natriuretic hormones in rat brain, the periaqueductal grey matter in dog brain may be an important source of both natriuretic hormones.

Animals↗