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Biomedical subjects

Y Osajima

Publications and source records attributed to Y Osajima.

33 records · Page 2Linked to original sources
PubMed1995

Antihypertensive effects of angiotensin fragments in SHR.

When angiotensin fragments, Val-Tyr and Angiotensin III (ANG III), with potent ACE inhibitory activity were intravenously administered to spontaneously hypertensive rat (SHR), a significant reduction of diastolic blood pressure was observed. After incubation of ANG III with SHR plasma, four fragments with ACE inhibitory activity, Val-Tyr (ANG (3-4)) (IC50 = 26.0 microM), Ile-His-Pro-Phe (ANG (5-8)) (11.6 microM), Tyr-Ile-His-Pro-Phe (ANG (4-8)) (457.5 microM), and Val-Tyr-Ile-His-Pro-Phe (ANG (3-8)) (6.55 microM), were confirmed to generate in SHR plasma. Compared the metabolic behavior of ANG II in SHR plasma with that in normotensive Wistar plasma, the initial degradation rate (3.07 nmol/ml/min) in Wistar plasma was about 2-fold higher than that in the SHR one (1.75 nmol/ml/min).

Amino Acid Sequence↗
PubMed1995

Sterilization of microorganisms by the supercritical carbon dioxide micro-bubble method.

Lactobacillus brevis and Saccharomyces cerevisiae were completely sterilized by the supercritical (SC) CO2 micro-bubble method. Gaseous (G) and liquid (LQ) CO2 were used in a similar manner to compare the sterilizing effect. Among the three treatments, the microorganisms were only effectively sterilized by the SC CO2 treatment at 25 MPa and 35 degrees C.

Carbon Dioxide↗
PubMed1994

Angiotensin I-converting enzyme inhibitory peptides in an alkaline protease hydrolyzate derived from sardine muscle.

The ACE inhibitory activity of an alkaline protease hydrolyzate from sardine muscle did not change after being treated by gastrointestinal proteases (IC50 = 0.082 mg protein/ml). Eleven new ACE inhibitory peptides, constructed with 2 to 4 amino acid residues, were isolated from the hydrolyzate. The ACE inhibitory activity of each was mostly below 100 microM of IC50 value; the maximal inhibitory activity was observed for Lys-Trp (IC50 = 1.63 microM). The isolated peptides inhibited ACE competitively, except for Met-Tyr with non-competitive inhibition. As the result of sequence homology, Arg-Val-Tyr isolated from the hydrolyzate was found in the primary structure of angiotensins I, II, and III, and of des As[1]-angiotensin I.

Amino Acid Sequence↗
PubMed1993

Inhibition of angiotensin I-converting enzyme by Bacillus licheniformis alkaline protease hydrolyzates derived from sardine muscle.

Hydrolyzates which inhibit the angiotensin I-converting enzyme (ACE) were prepared from sardine muscle by Bacillus licheniformis alkaline protease. Considering the practical application of preparations as a functional food material, the best proteolytic conditions with respect to taste, solubility and ACE inhibitory activity were a 0.3 wt% addition of the enzyme and 17-h proteolysis at 50 degrees C and pH 9.0. The preparations under these conditions had potent activity (IC50 = 0.26 mg protein/ml). Fractionation of the preparations on an ODS column with ethanol resulted in the production of more potent inhibitors. The most potent activity was obtained when eluting with 10% ethanol (IC50 = 0.015 mg protein/ml). This fraction was apparently rich in acidic amino acids, poor in hydrophobic ones, and effective for use as a physiologically functional food material by virtue of little bitterness, a fish odor and powerful ACE inhibitory activity.

Amino Acid Sequence↗
PubMed1990

Simultaneous determination of glucose, ethanol and lactate in alcoholic beverages and serum by amperometric flow injection analysis with immobilized enzyme reactors.

Glucose, ethanol and lactate were determined simultaneously in a flow injection system by using a parallel configuration of immobilized enzyme reactors. Hydrogen peroxide produced was monitored amperometrically at the potential of +0.65 V vs. Ag/AgCl. Linear relations between sensor responses and each species were observed in the ranges of 0.02-10 mM (glucose), 5 x 10(-4)-0.1% (v/v) (ethanol) and 0.005-1 mM (lactate) with correlation coefficients larger than 0.999 for each species. The relative standard deviations for 10 successive injections were 1.4, 0.5 and 1.1% for glucose (1 mM), ethanol (5 x 10(-3)% (v/v] and lactate (0.05 mM), respectively. Analysis of serum samples was performed with urate-eliminating reactors which were set just before each immobilized enzyme reactor. Interference of ascorbate in a serum sample was completely eliminated by using an ascorbate-eliminating reactor which was set before the sample injection valve. Application of the system to alcoholic beverages and control serum was described and the results were compared with those of free enzymatic, spectrophotometric analysis (F-kit or C-test method).

Alcoholic Beverages↗
PubMedDate not supplied

Isolation and identification of peptidic alpha-glucosidase inhibitors derived from sardine muscle hydrolyzate.

We report here the isolation of alpha-glucosidase (AGH) inhibitory peptides derived from sardine muscle hydrolyzate, which was prepared by digestion with Bacillus licheniformis alkaline protease. As a result of reversed-phase HPLC purification, two AGH inhibitory peptides were isolated from a DEAE-Sephadex A-25 column eluate. The peptides were identified as follows: Val-Trp (IC50 = 22.6 mM) and Try-Tyr-Pro-Leu (IC50 = 3.7 mM). AGH inhibitory studies of Try-Tyr-Pro-Leu and its derivatives demonstrated the importance of the tri-peptide chain length as well as the hydrophobic aromatic amino acid tyrosine at the N-terminus, aliphatic amino acids at the C-terminus, as well as an amide proton from the peptide chain at the middle position of the tri-peptide to develop AGH inhibition activity.

Animals↗