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Biomedical subjects

J Naito

Publications and source records attributed to J Naito.

At least 127 records · Page 7Linked to original sources
PubMed1983

[Studies on the inhibitory effect of etafenone hydrochloride on platelet aggregation].

The inhibitory effect of etafenone hydrochloride (etafenone) on platelet aggregation in rabbit platelet rich plasma and the involvement of the arachidonic acid (AA) cascade in the inhibitory mechanism for etafenone on platelet aggregation were studied. 1) Etafenone exhibited a dose-dependent inhibitory effect on collagen (15--20 micrograms/ml)-induced platelet aggregation, and its median inhibitory concentration (IC50) was 1.7 X 10(-5)M. 2) In ADP (20 microM)-induced aggregation, etafenone also exhibited a dose-dependent inhibitory effect, but its IC50 was 2.7 X 10(-4)M and was significantly higher than that in the case of collagen. 3) Etafenone inhibited AA (0.3--0.5mM)-induced platelet aggregation dose-dependently. Its IC50 was 2.8 X 10(-5)M. 4) In thromboxane (TX) A2-induced aggregation, etafenone exhibited a dose-dependent inhibition, and the IC50 was 3.2 X 10(-4)M. 5) Trapidil which was reported to inhibit platelet aggregation via phosphodiesterase (PDE) inhibition had a similar IC50 on ADP- and TXA2-induced platelet aggregation to that of etafenone, but in collagen- and AA-induced aggregation, its IC50 was higher than that of etafenone. 6) Etafenone (3 X 10(-6)--3 X 10(-4)M) dose-dependently inhibited the production of TXB2 in PRP induced by collagen. 7) Etafenone scarcely affected TXA2 synthetase activity in rabbit platelet homogenate. 8) The correlation between the inhibitory effect of etafenone on platelet aggregation and inhibition of AA metabolism activation and PDE inhibition was discussed.

Animals↗
PubMed1983

[Case of basal cell adenomas arising from the bilateral parotid glands].

A 64-year-old woman with basal cell adenomas of the bilateral parotid glands is presented. The tumor mass on the right side measured 5.5 X 5.8 cm; on the left it was 6.0 X 7.5 cm. Histologically, the right side tumor was of trabecular type, that of the left, tubular type of basal cell adenoma. The latter lesion had been present for the past 30 years, the former for six years. This may be the first reported case of bilateral basal cell adenomas of the parotid gland.

Adenoma↗
PubMed1982

Thalamocortical neurons projecting to the areas surrounding the anterior and middle suprasylvian sulci in the cat. A horseradish peroxidase study.

The thalamic projections to the cortical area surrounding the anterior (ASs) and middle (MSs) suprasylvian sulci in the cat were studied using horseradish peroxidase histochemistry. The medial MSs area (medial wall of the MsS) receives thalamic afferents from the pulvinar-lateralis posterior (Pul-LP) complex, posterior nucleus (Pn) and medial interlaminar nucleus (MIN) and C laminae of the dorsal lateral geniculate nucleus (GLd). Groups of labeled cells in the Pul-LP complex are arranged to form four different neuronal bands oriented dorsoventrally. The four neuronal bands are located, laterally to medially, in the lateral and medial parts of Pul and in the lateral and central parts of LP. The ventral ends of the first (in the lateral Pul) and the third (in the lateral LP) bands extend to MIN and Pn, respectively. The locations of the four bands in the Pul-LP complex appear to correspond to the terminal fields of afferents from four different regions (retina, pretectum, visual cortex and superior colliculus) related to visual function. The anterior part of the lateral MSs area (lateral wall of the MSs) receives thalamic fibers from the lateral and intermediate divisions of the posterior nuclear group (PO1 and POi), while its posterior part receives fibers from the dorsal and medial parts of LP and POi. Both walls of the ASs receive fibers from the ventrolateral part of LP as well as from the anterior part of PO1 and the PO1-POm border. In addition, the ASs-MSs area receives fibers from the central lateral nucleus (CL). It is of interest to correlate the locations of cells projecting to the ASs-MSs area with the pathways terminating in thalamic regions. It is clear that, from the hodological point of view, the ASs-MSs area is functionally segregated, which is in agreement with previous studies we have made corticocortical connections.

Afferent Pathways↗
PubMed1980

Corticocortical neurons projecting to the medial and lateral banks of the middle suprasylvian sulcus in the cat: an experimental study with the horseradish peroxidase method.

Corticocortical afferents to both cortical walls of the cat middle suprasylvian sulcus (MSs area) were investigated by means of retrograde axonal transport of horseradish peroxidase (HRP). the visual cortex (V-I and V-II) projects to the medial wall of the MSs, the projection from V-II being heavier. The auditory cortex (A-I, A-II,. and Ep), including cortical walls of the dorsal part of the anterior and posterior ectosylvian sulci, sends fibers to the lateral wall of the MSs. Connections from the first auditory area (A-I) are heavier than from the second (A-II). In the rostral part of the MSs, both the medial and lateral walls receive fibers from the somatosensory (S-I and S-II) cortex. A larger number of association fibers appear to arise from S-II than S-I. Although the MSs as a whole apparently receives various kinds of sensory inputs, there seems to be a parcellation of th MSs area such that the areas receiving cortical association fibers from the visual, auditory, or somatosensory cortical areas also receive thalamic projections from those parts of the thalamus receiving sensory connections of the same modality. The cells of origin of the association fibers were mostly pyramidal, the majority located in layer III (e.g., 80% in the visual cortex and 74% in the auditory cortex), some in layer V, and a few in other layers. Most (76-79%) of the labeled cell bodies were of 15-20 micrometer diameter. Smaller (8-15 micrometer) and larger (20-26 micrometer) cells constituted less than 15% in each case. The mean diameters were 17.0 +/- 2.8 (SD) in the visual cortex and 17.7 +/- 3.2 micrometer (SD) in the auditory cortex.

Animals↗
PubMed1980

Corticocortical connections of the cat sensory areas studied by means of retrograde axonal transport of horseradish peroxidase.

Afferent association connections to each functional cortex, i.e., the auditory, sensorimotor, visual, and "association" cortex, were investigated in the cat with the method of retrograde axonal transport of horseradish peroxidase (HRP). After injections of HRP in various parts of the cerebral cortex, a large number of labeled cells were found within the same functional areas, while a small number of cells were labeled in other cortical areas. This demonstrates that small parts within the functionally uniform cortical area are strongly interconnected by means of short association fibers. Labeled cells were found both in the cortex of the gyral surfaces and sulcal walls. Corticocortical neurons in the walls of some sulci were also shown to send their axons to various sensory areas. Cells of the origin of association fibers were mostly pyramidal in shape, occurring mainly in layer III of the various cortical areas (about 70% of the total number). Following injections of HRP suspension into the visual cortex, however, the majority of labeled cells (82%) were found in layers V and VI of the Clare-Bishop area, some of them were polygonal in shape. Somal diameters of the labeled cells were 15.8-17.2 micron (mean) +/- 2.5-3.0 (SD).

Afferent Pathways↗
PubMed1978

The metabolism of [carboxyl-14C]anthranilic acid. I. The incorporation of radioactivity into NAD+ and NADP+.

A new pathway of NAD+ synthesis from anthranilic acid was found in the livers of rats. Starting from [carboxyl-14C]anthranilic acid, radioactive NAD+ and NADP+ were produced as judged by Dowex-1 X 8-formate column chromatography followed by radiochromatography. Several intermediate compounds, such as quinolinic acid, nicotinic acid mononucleotide, and nicotinic acid adenine dinucleotide were also identified with the aid of various chromatographic techniques. In the experiments with liver microsomal hydroxylation systems, anthranilic acid was converted into not only 5-hydroxyanthranilic acid but also 3-hydroxyanthranilic acid.

Animals↗
PubMed1978

[Distribution of association fibers impinging upon the middle suprasylvian sulcus area (MSs area) in the cat (author's transl)].

Following lesions of various cortical areas of altogether 13 adult cats, the distribution of degenerating fibers in the cortical area surrounding the middle suprasylvian sulcus (MSs area) has been studied with the method of Fink and Heimer. Association fibers from the visual cortex mostly end in the vicinity of fundus of the medial wall of the MSs area and a fair number of fibers do in the fundus area of the posterior portion of its lateral wall. Most of the fibers terminate in layers III-V. Fibers from the auditory cortex terminante in the lip of the lateral wall, while few fibers end in the fundus and the medial wall. The fibers from the somatosensory cortex chiefly end in the vicinity of the fundus terminate in layers III-V. The "association cortex" sends a good amount of fibers to the lip region and the upper area of the media wall and lesser amount to the posterior part of the lateral wall of the MSs. The fibers terminant in layer III. From the present and the previous findings, it has become evident that inputs of different kinds of sensory modalities converge upon th elayers III-IV of the MSs area from the various cortical functional areas, and that the MSs area also sends fibers back to the sensory cortical areas. In addition, it has reciprocal connections with some thalamic nuclear groups, e.g., the "pulvinar posterior" system. Based upon the findings of neuronal connections, it can be suggested that the MSs area may play an important role with regard to the "integration of sensory inputs" in the cat cerebral cortex.

Animals↗
PubMed1978

[Pharmacological properties of N-(3',4'-dimethoxycinnamoyl) anthranilic acid (N-5'), a new anti-atopic agent. (3).--Influence on homologous passive cutaneous anaphylaxis mediated by homocytotropic antibody (author's transl)].

N-5' shows a potent inhibitory action on the homologous passive cutaneous anaphylaxis (PCA) in rats mainly through the inhibition of histamine release from mast cells. The present experiment was an attempt to clarify in detail the pharmacological properties of N-5'. Inhibition of PCA was most potent at 30 or 60 min pretreatment with N-5', and negligible at 240 min pretreatment. Given p.o., N-5' produced a dose-dependent, potent inhibitory action at 30-min pretreatment. On the other hand, disodium cromoglycate (DSCG) had little effect on PCA when given orally. On the case of i.v. administration, N-5' (20 mg/kg) and DSCG (5 mg/kg) showed a most potent inhibition of PCA at 5 min pretreatment. The inhibitory action of DSCG was, however, shorter lasting than that of N-5'. Median effective doses (ED50) of DSCG and N-5' on the PCA were estimated to be 0.79 and 8.8 mg/kg i.v., respectively. Inhibitory activity of N-5' in the adrenalectomized rat did not differ from that in sham operated animals. N-5' had a more potent inhibitory action on the PCA in infant rats than in adults. Inhibitory activity of N-5' in the case of 1, 2, 3 and 4 weeks of successive administration was equipotent to that with a single administration.

Administration, Oral↗
PubMed1978

Variations of the dog cerebral sulci, compared in particular with those of the cat.

Various types of 15 sulci, ill on the lateral and 4 on the medial surface, of the dog cerebral hemisphere, were examined. Each sulcus has several formes and a sulcal pattern which shows the highest frequency is taken as a "standard" type. A standard map of the dog brain is presented based upon the present observation. Sulcal patterns of the dog cerebrum are in general as consistent as those of the cat brain. However, some sulci, i.e., a small branch of the suprasylvian sulcus, the suprasplenial and postsplenial sulci, the ectolateral, the genual, the prorean, and the eetosylvian sulcus, show variety of formes. Variations of the dog sulci are discussed and compared with those of the cat. The comparison shows that the sulcal patterns which appear only in the dog are on the whole most variable.

Animals↗
PubMed1976

[Pharmacological analysis of effects of perimetazine on isolated smooth muscle].

Effects of perimetazine on the motility of the isolated smooth muscle of guinea pig (ileum, taenia coli, uterus, vas deferens and trachea) and the ileum of rabbit were studied. The results obtained are as follows: Perimetazine showed a specific antihistamine, antiadrenaline and antiserotonin action. Moreover, antiacetylcholine and anti-BaC12 actions were observed with high doses of perimetazine as well as chlorpromazine and such actions were attributed to the nonspecific direct action on the smooth muscle. Both the spontaneous movement and the tonus of guinea pig taenia coli were also inhibited by a high concentration of perimetazine. The spontaneous membrane action potentials of the taenia coli recorded by the use of the sucrose-gap method were inhibited by a high concentration of perimetazine both in frequency and in amplitude with relaxation of the tonus. The action potentials were abolished however and change in the resting membrane level was not clearly observed.

Acetylcholine↗
PubMed1975

Dietary and hormonal regulation of serine synthesis in the rat.

The importance of the so-called phosphorylated pathway for the synthesis of serine in rat liver was confirmed by studies on in vitro serine synthesis and also by the existence of a correlation between the serine-synthesizing activity of liver extracts and the activities of the enzymes involved in the pathway under various dietary conditions. Serine-synthesizing activity was found to be distributed in various rat tissues such as kidney, brain, testis, spleen, pancreas, and fat pad. However, only in the liver was the synthesis regulated by dietary protein. In the liver, the three enzymes of the phosphorylated pathway were found to be repressed by high-protein diets or by starvation and induced by low-protein diets. The dietary induction of the enzymes required the presence of insulin and was suppressed by glucocorticoids. A suggestion is made that the effects of diet or hormones may be mediated by changes in the hepatic pool of essential amino acids.

Animals↗
PubMed1975

Studies on the metabolic pathway of anthranilic acid in rats.

Recent experiments with administration of anthranilic acid in rats afforded two new metabolites; anthranilamide and a light blue fluorescent substance. Administration of anthranilamide to rats resulted in urinary excretion of two main metabolites which were isolated from urine as 3-hydroxyanthranilamide-O-sulfate and 5-hydroxyanthranilamide-O-sulfate. This fact showed that anthranilamide is hydroxylated and then conjugated in vivo. Hydroxylation of anthranilamide was found to be catalyzed by drugs hydroxylation system but not by the microsomes alone, and is a specific reaction activated by a protein component contained in the soluble fraction. The purified protein component was recongneized that it was bluish green protein containing copper and zinc, and its molecular weight was 25,700. This protein component had no effect on the metabolism of drugs by liver microsomes but showed specific activation of hydroxylation of 2-aminobenzoyl compounds.

Amino Acids↗