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Biomedical subjects

H Kohri

Publications and source records attributed to H Kohri.

12 recordsLinked to original sources

Determination of absorption and endogenous excretion of iron in man by monitoring fecal excretion of a stable iron isotope (58Fe).

The absorption and endogenous excretion of iron in man was studied by monitoring the fecal excretion of a stable iron isotope (58Fe). The study was carried out for 12 healthy volunteers who were divided into two groups. Group I received 58Fe-labeled ferric ammonium citrate (III) (58FeAC) equivalent to 6 mg of iron as a control, and group II received a combination of 500 mg of vitamin C and 58FeAC. A new formula was used to calculate the 58Fe absorption ratio reflecting the pool of iron in the intestinal cells, and the ratio was compared with that obtained from Janghorbani's formula, which has been used as one of the common methods. As a result, the 58Fe absorption ratio in group II was statistically significantly higher than that of group I (34.4 +/- 6.1% vs. 15.0 +/- 5.5%, M +/- SD) using Janghorbani's formula. The similar absorption ratio (34.1 +/- 6.0% vs. 14.8 +/- 5.5%) was also obtained by our new formula. Our results confirmed the previous findings that the availability of iron is stimulated by the supplementation of vitamin C. Both formulae agreed in the absorption of iron, indicating that the endogenous excretion of iron (caused by the desquamated cells) in the intestine does not disguise the iron absorption.

Absorption

Practical debittering using model peptides and related compounds.

In order to develop a practical debittering method for amino acids and peptides, several debittering methods were studied. The authors found that hooking acidic amino acids to and acetylation of bitter amino acids is very effective to remove the bitterness from their concentrated solution. For debittering by mixing with additives, skin milk and other peptide compounds were effective. Acidic amino acids were also effective to reduce the bitterness. Gelatinized starch was found to be useful for debittering because it takes bitter substances into its net structure.

Amino Acid Sequence

Metabolic fate of carteolol hydrochloride, (OPC-1085) VIII, a new beta-adrenergic blocking agent. Pharmacokinetic studies of carteolol in man.

The pharmacokinetics of 5-(3-tert.-butylamino-2-hydroxy)-propoxy-3,4-dihydrocarbostyril hydrochloride (carteolol hydrochloride, OPC-1085) have been investigated in man following single or repetitive oral administration. The plasma half-lives. The plasma half-lives of carteolol at single doses of 10, 15 and 30 mg were 5.4, 5.5 and 5.0 h, respectively. The amounts of carteolol excreted into urine within 24 h at the same dose levels accounted for 64, 70 and 76% of the respective doses. The half-lives obtained by the Sigmaminus method were 5.6, 5.6 and 5.4 h, respectively, being essentially consistent with the aforementioned plasma half-lives of carteolol after administration at 15 mg daily for 7 successive days were determined to be 5.54 h on the 1st day and 6.91 h on the 7th day, displaying the increase in half-life value with the repetitive dosing. While, the predicted value determined using the experimental value on the 1st day agreed with the experimental value on the 7th day. Furthermore, the amounts of carteolol excreted in the urine were not significantly different between the 1st and 7th days. The 7-day repetitive administration with carteolol brought about the steady state of plasma levels. It was concluded from these results that carteolol has little ability to accumulate in man.

Adrenergic beta-Antagonists

[Metabolic fate of carteolol hydrochloride (OPC-1085), a new beta-adrenergic agent. (3) Autoradiographic total body distribution studies in mice].

Distribution of a new beta-adrenergic blocking agent, 3H-carteolol in mice was studied by whole body autoradiography. The distribution of radioactivity was observed in all organs except the eyes and brain, with particularly high specific activities in the kidneys, liver, gall bladder and content in the intestines within a short time after either oral or intravenous administration. The radioactivity was then promptly eliminated from all tissues and organs, and excreted almost entirely in the urine and bile. Propranolol is known to be distributed at a high concentration in the brain, whereas the concentration of (3H-) carteolol detectable in the brain was slight. In the adrenal gland, the radioactivity was localized in the medulla. Radioactivity was detected also in the stomach contents after the intravenous administration. The distribution of radioactivity in the fetus through the placenta was less than that in the major organs of the mother mouse, and the elimination of the activity was more rapid in the fetus than in mother. These findings indicate that carteolol and its metabolites do to some extent pass through the blood-brain barrier and placenta.

Adrenergic beta-Antagonists