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Biomedical subjects

Y Shibata

Publications and source records attributed to Y Shibata.

At least 739 records · Page 41Linked to original sources
PubMed1978

On the regulation of tryptophan metabolism "via" kynurenine.

The tryptophan leads to nicotinic acid pathway is inhibited in the nicotinic acid administered rats; in this case tryptophan chiefly metabolizes "via" serotonin. The serotonin pathway is inhibited in the excess phenylalanine administered rats, especially due to the inhibition of the tryptophan-5-hydroxylase reaction. Xanthurenic acid inhibits kynurenine-3-hydroxylase in vitro, which is a very important regulatory enzyme for xanthurenic acid and nicotinic acid production.

Animals↗
PubMed1977

Gap junctions in the cardiac muscle cells of the lamprey.

Electron microscopy of both thin sections and freeze-fracture replicas has demonstrated the occurrence of gap junctions (nexuses) in the cardiac muscle cells of the lamprey. These gap junctions are identical in basic structure with those found in the mammalian heart. However, they are much smaller (less than 0.5 micron in diameter), and more irregularly distributed than the typical gap junction in the mammalian heart. These small gap junctions seem to provide a structural basis for the electrical coupling between cardiac muscle cells in the lower vertebrates. In addition, the well developed sarcoplasmic reticulum and subsurface cisternae, which contain an electron dense spheroidal cast, frequently observed in the cardiac muscles of the lamprey.

Animals↗
PubMed1977

Anti-inflammatory, analgesic and other related actions of 4'-chloro-5-methoxy-3-biphenylylacetic acid (DKA-9).

4'-Chloro-5-methoxy-3-biphenylylacetic acid (DKA-9) is a novel phenylacetic acid derivative with marked anti-inflammatory, analgesic and antipyretic activities. DKA-9 was approximately 2 times and 25 times more effective than ibuprofen in inhibiting carrageenin-induced paw edema and adjuvant-induced arthritis, respectively, in rats. The anti-inflammatory effect of DKA-9 was observed also in adrenalectomized rats. In the Randall-Selitto test in rats, DKA-9 was about 2 times more potent than ibuprofen and equipotent to indometacin. In lowering brewer's yeast-induced fever in rats, DKA-9 was almost 1/2 times more effective than ibuprofen. Considering from therapeutic index (ED50 in ulcerogenic effect/ED50 in carrageenin-induced edema), DKA-9 was found to be much superior to indometacin or ibuprofen.

Analgesics↗
PubMed1976

Fine structure and cytochemistry of specific granules in the lamprey atrium.

Fine structural and cytochemical studies were performed to examine the nature of three types of specific granules found in the atrium of lamprey; specific granules of the atrial muscle cell (ASG), interstitial cell granules (ICG) and endocardial endothelial granules (ESG). Ultrastructurally, ASG and ICG appeared quite similar in size, shape and electron opacity, while ESG were much larger and less dense in opacity than the other two. None of the granules showed positive DAB reaction or acid phosphatase reaction. Only ICG revealed positive chromaffin reaction, which agreed with formaldehyde induced green fluorescence along the atrial lumen. Phosphotungstic acid at low pH stained ICG and ASG strongly positive, and ESG weakly positive. Pronase treatment in Epon sections for 24 h digested ASG alone, whereas in glycol-methacrylate embedded sections, ESG were digested first, ASG were digested thoroughly after 30 min, but ICG were not digested completely after 90 min. From these results it can be concluded that the three types of specific granules have different constituents. ESG consist of protein with some polysaccharides; ASG are composed of protein carbohydrate complexes and lack catecholamines; ICG contain catecholamine as well as protein carbohydrate complexes.

Acid Phosphatase↗