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Biomedical subjects

K Ochi

Publications and source records attributed to K Ochi.

231 records · Page 13Linked to original sources
PubMed1976

[Role of the intramural ganglion cells played in the motility of the large intestine of the tortoise, Geoclemys reevesii].

The development of the intramural plexuses in the tortoise, Geoclemys reevesii was inferior to that observed in the fowl: the meshes of both Auerbach's and Meissner's plexuses were coarser, and consisted of less number of nerve fibers. Occasionally, a small ganglion was seen at the crossing points of the meshes. The average number of nerve cells contained in the ganglion was estimated to be 1500/cm2, being about half as much as that estimated in the fowl. When the mucosa of a colon in vitro was stimulated mechanically by stroking or chemically with 1/10 N HCl, the excitability of the colonic muscle was raised at the region oral to the stimulated spot, but lowered at the region anal to it. These effects were abolished by applying a ganglion-blocking agent, hexamethonium (10(-6) g/ml), to the mucosa. When the intraluminal pressure of a colon in vitro was raised from 0 to 3-12 cm H2O, the colon was distended at first but soon contracted powerfully. The contraction became extremely reduced or was abolished when hexamethonium (3.5X10(-7) approximately 1X10(-5) g/ml) was added to the saline solution in which the colon was immersed. The results indicate that the intramural ganglion cells serve as the center of the intrinsic mucosal reflex.

Animals↗
PubMed1976

Biosynthesis of formycin. Incorporation and distribution of labeled compounds into formycin.

1. Two carbons, carbon-2 and one of carbons-3 to -5, of lysine seemed likely to be incorporated into one of carbon of the chromophore moiety of formycin. 2. From the results of radioisotopic studies with glutamate, gamma-amino-n-butyrate or organic acids related to tricarboxylic acid cycle, the important role of glutamate in the biosynthesis of formycin was strongly suggested. 3. The incorporation of nitrogen(s) of lysine into three nitrogens, including two nitrogens of pyrazole ring, of formycin was suggested by mass spectroscopy. 4. Ribose was estimated as a direct precursor moiety of formycin, whereas the biosynthesis of ribose was shown to occur via the pathway other than hexose monophosphate shunt or glucuronate pathway. 5. In replacement culture, the salvage synthesis of formycin from its chromophore moiety was not observed and it was also evident that the chromophore moiety or pyrazofurin (pyrazomycin) inhibited the biosynthesis of formycin.

Adenine↗
PubMedDate not supplied

Immunocytochemical demonstration of beta 1-subunit of Na+/K(+)-ATPase in the mechanoreceptive Ruffini-like endings of the rat incisor ligament.

The localization of one of the isoforms of Na+/K(+)-ATPase, the beta 1-subunit, was investigated in the periodontal Ruffini endings of rat incisors by light- and electron-microscopic immunocytochemistry. Immunoreactivity for the rat beta 1-subunit followed the pattern of dendritic terminal arborization in the alveolar half of the lingual periodontal ligament. Ultrastructurally, the reaction products were localized in dilatations of axons, possibly the terminals of Ruffini-like endings in the periodontal ligament. No immunoreactivity was seen in Schwann cells. The immunostaining results support the view that the beta 1-subunit of Na+/K(+)-ATPase is the predominant isoform in sensory neurones, and that this protein is a useful marker for periodontal Ruffini-like endings.

Alveolar Process↗
PubMedDate not supplied

Calbindin D28K-like immunoreactive nerve fibres in the predentine of rat molar teeth.

Immunoelectron-microscopy was applied to reveal the existence of nerve fibres and terminals showing calbindin D28k (CB)-like immunoreactivity (IR) in the rat molar tooth pulp. In the root pulp, thick, smooth-surfaced CB-IR nerve fibres were in bundles accompanying the blood vessels. In the coronal pulp, the fibres arborized repeatedly and extensively. CB-IR nerve fibres had a predominantly thick, smooth-surfaced appearance, though parts appeared thin and beaded. Occasionally some thin, varicose CB-IR nerve fibres ran along the odontoblasts, penetrating into the predentine alongside the dentinal tubules. They could be traced for approx. 10-20 microns into the predentine from the pulp-predentine border. Immunoelectron-microscopy revealed that only some of the nerve terminals in the predentine showed CB-IR, and that predentinal CB-IR nerve terminals were located close to the odontoblast processes. No synaptic structures were observed between them. The presence of CB-IR nerve terminals in the predentine suggests that many, if not all, CB-IR nerve fibres could be nociceptors. The CB could be involved in Ca2+ homeostasis during the activation of nociceptors.

Animals↗
PubMedDate not supplied

Production of angiotensin-converting enzyme in rat epididymis.

Unilateral ductuli efferentia testis of immature rat were severed in order to interrupt the continuity between testis and epididymis and angiotensin-converting enzyme (ACE) activities were measured 5 weeks after the operation. The epididymal ACE on the operated side increased to nearly the same level as that on the contralateral side, but the testicular ACE activity on the operated side was markedly lower than that on the contralateral side. On immunofluorescent study using antiserum against purified rat lung ACE, ACE could be found in the tubular epithelial cells of the operated epididymis. These results suggest that epididymis itself synthesize ACE without connection to testis.

Animals↗