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Biomedical subjects

M Aono

Publications and source records attributed to M Aono.

At least 163 records · Page 9Linked to original sources
PubMed1981

Effect of topical application of amino acids on gastric pepsin secretion in the rat.

The effect of amino acids and other chemicals of intragastric perfusion on pepsin secretion was studied in anaesthetized rats. Irrigation of the stomach with glycine caused concentration-dependent increase in pepsin output, but not in acid output. Pepsin stimulatory effect was decreased by an increase of the carbon chain between the amino group and carboxyl group of glycine and by transposing the amino group from alpha- to gamma-position in amino-n-butyric acid. Acidification of perfusate, a local irrigation of lidocaine and an intravenous infusion of atropine reduced but did not abolish the pepsin response to chemical stimulation. Since serum gastrin level was not changed from basal levels during pepsin secretion induced by amino acids, the mechanism of chemical stimulation appears to be gastrin-independent. The comparison of the secretagogue activity of amino acids shows that glycine exhibited the strongest stimulation of pepsin output, reaching 208% of the response to tetragastrin at the dose of 8 microgram/kg/hour. All other amino acids tested were found to stimulate pepsin secretion, whereas bovine serum albumin and hydrochloric acid were inert in this respect. The result indicates that the chemical stimulation of the stomach by amino acids is capable of inducing pepsin secretion by a local, gastrin-independent mechanism sensitive to pH and related to the molecular configuration of amino acids.

Amino Acids↗
PubMed1981

Effect of topical application of amino acids on gastric pepsin secretion in the rat. Part II: effect of pH changes and glycine in separate perfusion preparation.

Gastric acid and pepsin were measured in antrum and fundus separately by perfusing each region of the stomach in anaesthetized rats. Perfusion of the antral region with alkaline and acid solutions did not affect gastric acid and pepsin secretions in the fundic gland region. Gastric secretions in the antrum and acid secretions in the fundus remained unchanged when each region of the stomach was instillated with glycine. Pepsin stimulation was observed in the fundic region only when perfused with glycine. We confirmed our previous observation that topical amino acid in the oxyntic gland stimulated pepsin secretion directly. The pepsin stimulatory effect of amino acid was found to be independent of antral regulation.

Administration, Topical↗
PubMed1981

Effect of topical application of amino acids on gastric pepsin secretion in the rat. Part III: effect of L- and D-isomers of amino acids on gastric secretion in reperfusion system.

This study was undertaken to compare the potency of each L- and D-isomers of 5 amino acids in stimulating gastric acid and pepsin secretion by the intragastric reperfusion preparation in rats. Gastric basal and glycine-stimulated secretions in this preparation were lower than those Ghosh-Lai preparation, but not to a statistically significant extent. All D- and L-isomers of amino acids tested were found to markedly stimulate pepsin secretion, but to only slightly stimulate acid secretion. Pepsin stimulatory response to each D and L-isomer of amino acid was similar. The stimulatory effects of amino acids thus seem to be unrelated to the optical stereoisomeric configuration.

Administration, Topical↗
PubMed1981

The para-carotid approach for internal jugular catheterization.

We have developed a para-carotid approach for internal jugular cannulation which utilizes only the carotid artery as a landmark. This technique allows us to locate-the puncture site regardless of an individual patient's physical, skeletal or postural variations. This study was undertaken in the period from January 1979 to June 1980 on 456 consecutive patients in wide range of age groups and various clinical conditions. The overall success rate was 96.1%. The only complications encountered during our study were five carotid artery punctures with formation of two haematomas.

Adolescent↗
PubMed1981

Fibrinolytic activity in periodontal disease. The relationship between fibrinolytic activity and severity of periodontal disease.

IN RECENT YEARS, evidence has evolved that suggests a relationship between fibrinolytic phenomenon and various inflammatory diseases. Plasmin activity and the response of the fibrinogen and fibrin degradation products latex test (FDPL test) in gingival fluid, along with plasminogen activator activity in gingival tissue were assessed. Samples were taken from periodontally involved persons and compared with healthy individuals. The following conclusions could be drawn: (1) The fluid from inflamed gingival crevices possessed more plasmin activity than that from clinically healthy crevices. The reaction of the FDPL test was stronger in the former. (2) Plasminogen activator activity in gingival tissue showed no significant difference between periodontally involved and healthy subjects.

Alveolar Process↗
PubMed1981

Studies on peptides. CII. Synthesis of a heptacosapeptide amide corresponding to the entire amino acid sequence of gastrin-releasing peptide.

The heptacosapeptide amide corresponding to the entire amino acid sequence of gastrin-releasing peptide (GRP) was synthesized by assembling seven peptide fragments followed by deprotection with a new reagent system, IM trifluoromethanesulfonic acid-thioanisole in TFA. The deprotected peptide was purified by ion-exchange chromatography on CM-cellulose followed by partition chromatography on Sephadex G-25. The latter was found to remove effectively the Met (O) derivative of GRP. The highly purified synthetic GRP was active as synthetic bombesin on the molar basis. A new carboxyl-activating reagent, thiazoline-2-thione, was employed for preparation of the necessary fragments.

Amino Acid Sequence↗
PubMed1980

The role of gastric mucosal hexosamine in aspirin-induced ulcers.

In order to elucidate the role of gastric tissue hexosamine, used as an index of mucopolysaccharide content, in the development and healing process of peptic ulcers, the distribution of hexosamine and the changes of gastric hexosamine content in the development and healing of aspirin-induced ulcers in rats were studied. In addition, the effects of proglumide and L-glutamine on gastric hexosamine were also studied. The hexosamine content was found to be the highest in the antrum, followed by the corpus and then the forestomach. The mucosa contained significantly higher hexosamine than the smooth muscle layer in both the antrum and the corpus. Prior treatment with proglumide significantly increased the mucosal hexosamine to the extent of 10.3--18.1% in the glandular stomach. Administration of aspirin decreased the gastric mucosal hexosamine and induced the onset of ulcer, while administration of proglumide suppressed the gastric lesions in proportion to dosage and correspondingly prevented a decrease of the hexosamine. In contrast, L-glutamine showed an anti-ulcerogenic effect without suppressing a decrease of the hexosamine. In the process of curing gastric lesions, proglumide accelerated the healing of the ulcers and simultaneously returned the total hexosamine content to its original level. These results suggest that the gastric mucosal hexosamine is closely related to the onset and healing of aspirin-induced ulcer in rats, and that proglumide contributes to both the prevention and healing of ulcers by increasing gastric mucosal hexosamine.

Animals↗
PubMed1980

The activity of N-acetylglucosamine kinase in rat gastric mucosa.

The activity of N-acetylglucosamine kinase in the rat glandular stomach was studied to elucidate its participation in aspirin-induced ulcers, and the effect of proglumide, an anti-ulcer agent which was found to increase gastric mucosal hexosamine, on this enzymatic activity was also studied. N-Acetylglucosamine kinase activity was found to be significantly higher in the antrum than in the corpus, the antrum being 1.3--1.9 times as active as the corpus. The mucosal layer itself was about 1.8--2.0 times as active as the whole tissue of the glandular stomach. This enzymatic activity in the glandular stomach was found to decrease slightly after fasting and to further decrease after intragastric administration of aspirin (100 mg/kg). The pylorus-ligated rats showed a significant decline of this enzymatic activity following the administration of aspirin. Acceleration of N-acetylglucosamine kinase activity with proglumide was demonstrated in vivo and in vitro experiments. Prior treatment with proglumide prevented aspirin-induced ulcers and correspondingly stimulated this enzymatic activity. These results suggest that the activity of N-acetylglucosamine kinase in the rat glandular stomach closely parallels the distribution and localization of gastric hexosamine, glycosaminoglycans, and glycoproteins. A decrease of this enzymatic activity correlates with the production of ulcers by aspirin. The mechanism by which proglumide increases gastric hexosamine is at least partly attributed to the activation of N-acetylglucosamine kinase in the glandular stomach.

Animals↗