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S Shibata

Publications and source records attributed to S Shibata.

At least 793 records · Page 44Linked to original sources
PubMed1983

[Nephritogenic glycoprotein isolated from human placenta (methods of isolation from placenta].

In our experiments, we succeeded in obtaining from human placenta a substance comparable to human renal nephritogenic glycoprotein prepared from GBM (glomerular basement membrane). The procedure was quite similar to that for preparation from the kidney. At first, placental terminal villi were isolated by the successive use of three metal sieves. Then trophoblast basement membranes (TrBM) were isolated from placental terminal villi by ultrasonic disruption. Finally TrBM were made soluble by trypsin digestion, after which they were further digested by pronase. Ouchterlony gel diffusion demonstrated the existence of a common precipitin line between antiserum to human renal nephritogenic glycoprotein prepared from GBM and antiserum to the sample prepared from human placental TrBM, and human renal nephritogenic glycoprotein prepared from GBM and the sample prepared from human placental TrBM. The monosaccharide composition of the sample prepared from human placental TrBM was rich in glucose (glucose, galactose and mannoside in the ratio of 1.00 : 0.74 : 1.00), and the amino acid composition of the sample contained no collagenous components. As a result of fractionation of the sample prepared from human placental TrBM by Bio Gel P200 column chromatography, the activity of renal nephritogenic glycoprotein was found within the void fraction.

Basement Membrane↗
PubMed1982

Imidazole-induced potentiation of the contractile response to various agonists in vascular smooth muscle.

In isolated rabbit aortae, imidazole (10(-4)M) caused a unique nonspecific potentiation of the contractile responses to prostaglandins, norepinephrine, 5-hydroxytryptamine, histamine and potassium only at low concentrations. Imidazole had no effect on the dose-response relationship for Ca2+ in the presence of potassium, 40 mM. Imidazole potentiated contractions in supersensitive strips pretreated with reserpine or with low temperature (5 degrees C) for 5 days. In the presence of theophylline (3 x 10(-4)M), imidazole failed to potentiate the responses to norepinephrine, 5-hydroxy-tryptamine, histamine and potassium, but significantly potentiated responses to prostaglandin E1, E2 and F2 alpha. Imidazole (10(-4)M) significantly decreased the 45Ca uptake of aorta in a Ca-free solution, whereas the drug did not affect 45Ca uptake in a normal solution. These results suggest that imidazole-induced potentiation is related to an increase in Ca2+ permeability and possibly to an additive effect on Ca2+ binding.

Animals↗
PubMed1982

Isolation and characterization of a Lewis b-active lectin from Griffonia simplicifolia seeds.

A fourth lectin (GS IV), a serologically Lewis b (Leb)-active binding lectin, was isolated from Griffonia simplicifolia seeds by affinity chromatography on an Leb (alpha-L-fucose-(1 leads to 2)-beta-D-Gal-(1 leads to 3)-[alpha-L-fucose-(1 leads to 4)]-beta-D-GlcNAc)-active fragment coupled to Synsorb, followed by elution with 0.1 N acetic acid. The purified lectin was shown to be homogeneous by polyacrylamide gel electrophoresis and analytical gel column chromatography on Sephadex G-200. A glycoprotein containing mannose, N-acetylglucosamine, fucose, and xylose (4:2:1:1), the lectin is a dimer composed of subunits of Mr = 29,000 and 27,000 with an aggregate Mr = 56,000. The GS IV lectin precipitate equally with blood group Leb fragment-bovine serum albumin (BSA) and H-active fragment (alpha-L-fucose-(1 leads to 2)-beta-D-Gal-(1 leads to 4)-[alpha-L-fucose-(1 leads to 3)]-beta-D-GlcNAc)-BSA conjugates but only poorly with a Lewis a fragment-BSA conjugate. Inhibition of precipitation with various mono- and oligosaccharides indicated that the lectin is specific for type 1 or 2 chains containing two alpha-L-fucosyl groups on C-2 of the D-galactosyl residue and C-3 or C-4 of the D-GlcNAc unit. One alpha-L-fucosyl residue on C-3 or C-4 of the D-GlcNAc residue of type 1 or 2 chains inhibited the reaction, although these oligosaccharides were less active than the oligosaccharides containing 2 alpha-L-fucosyl units. L-Fucose, methyl alpha- or beta-fucoside, and p-nitrophenyl alpha- or beta-L-fucoside did not inhibit the lectin. GSIV did not display mitogenic activity against mouse spleen cells or human peripheral lymphocytes.

Amino Acids↗
PubMed1982

Sugar composition of the nephritogenic glycopeptide, nephritogenoside, isolated from rat glomerular basement membrane.

Water-soluble and non-dialyzable glycopeptide, nephritogenoside, was isolated from the glomerular basement membrane of normal rats. The yield of the purified nephritogenic glycopeptide from the glomerular basement membrane of 1200 rats was only 17.2 mg. Hexose amounted to 24.3% by weight, and consisted only of glucose. Paper chromatographic studies on the number and length of the carbohydrate chain deduced from strong alkaline cleavage in the presence of sodium borohydride strongly suggested that the carbohydrate chain of the nephritogenic glycopeptide is composed of three glucose residues. This conclusion was supported by the 13C-NMR spectroscopic results. In the paper chromatographic studies on the monosaccharides produced from 3H-labeled oligosaccharide by alkaline degradation and then acid hydrolysis and studies on the 13C-NMR spectrum, it was demonstrated that the saccharide at the reducing terminus is glucose. Thus, the glucose residue at the reducing terminus of the nephritogenoside may be linked directly (probably N-glycosidically) to amino acid, without the intervention of N-acetylglucosamine. The proposed structure of the carbohydrate portion of the nephritogenic glycopeptide, nephritogenoside, is as follows: (formula in text)

Animals↗
PubMed1982

Changes in amygdaloid afterdischarges and kindling effect following olfactory bulbectomy in the rat.

Changes in the thresholds for afterdischarges and the formation of kindling effect in the medial amygdala following olfactory bulbectomy were investigated in the rat with chronic electrode implants. The threshold for afterdischarges in the amygdala of the olfactory bulbectomized rat (OB rat) was significantly decreased on day 4 after olfactory bulbectomy, however, no significant difference was found between OB and sham operated rats on days 7, 14 and 21 since the threshold in the sham group was also decreased at these periods after the surgery. The formation of kindling effect was remarkably accelerated in the OB rats. In this case, the number of days required to reach the stage 1 (Racine's classification) was significantly shortened. These results suggest that the activity of the medial amygdaloid nucleus is increased following olfactory bulbectomy.

Aggression↗
PubMed1982

Differential effects of medial, central and basolateral amygdaloid lesions on four models of experimentally-induced aggression in rats.

To clarify whether various nuclei of the amygdaloid complex play different roles in aggressive behavior including muricide, 4 types of aggression were experimentally induced in rats. These include olfactory bulbectomy (OB rats), midbrain raphe lesions (Raphe rats), administration of delta 9-tetrahydrocannabinol (THC rats) and long-term isolation (Iso rats). Rats which exhibited muricide following these treatments were subjected to bilateral lesions of either the medial (AME), central (ACE) or basolateral (ABL) amygdaloid nuclei. Both muricide and hyperemotionality in the OB rat were markedly inhibited by AME lesions. Those of the Iso and THC rats were moderately inhibited. However, in the Raphe rat, aggressive behavior was not inhibited by AME lesions. Furthermore, ACE or ABL lesions caused no significant changes in all 4 models of aggression. These results suggest that the AME plays a facilitatory role in aggression of OB, Iso and THC rats, but aggression in Raphe rat is independent of amygdaloid activity.

Aggression↗
PubMed1982

Effects of medial amygdaloid lesions on the initiation and the maintenance of muricide in olfactory bulbectomized rats.

In order to elucidate the role of medial amygdala on the initiation and the maintenance of muricide following olfactory bulb lesions, bilateral medial amygdaloid lesions were performed after, prior to, or simultaneously with olfactory bulb lesions. Both the initiation and the maintenance of muricide following olfactory bulb lesions were suppressed by amygdaloid lesions, and this result suggests that the medial amygdala plays a facilitatory role in both the initiation and the maintenance of muricide in olfactory bulbectomized rats.

Aggression↗
PubMed1982

Ontogenesis of glucose sensitivity in the rat lateral hypothalamus: a brain slice study.

The development of glucose-sensitive neurons in the lateral hypothalamus (LHA) brain slices was examined. In 60-100-day-old rats, 20% of LHA neurons were sensitive, that is, their firing rates decreased upon increase in the glucose concentration in the perfusate and increased upon decrease in glucose concentration. In 2-, 3- and 7-day-old rats, 16% of the neurons were glucose sensitive. Results confirm glucose-sensitivity in the LHA at a very early stage of ontogeny.

Animals↗
PubMed1982

Neuronal control of the ventromedial nucleus from the periventricular nucleus in the hypothalamic slice of the rat.

A neuronal pathway between periventricular nucleus and ventromedial hypothalamus (VMH) was investigated by both anatomical and electrophysiological methods. Horseradish peroxidase (HRP)-labelled clusters were observed in the periventricular nucleus after application of HRP into the VMH. Periventricular nucleus stimulation produced mainly excitation of VMH neurones with a latency of 3 msec. These results suggest that periventricular nucleus sends information in the cerebro-spinal fluid to the VMH.

Animals↗
PubMed1982

Stimulated macrophages express a new glycoprotein receptor reactive with Griffonia simplicifolia I-B4 isolectin.

This paper presents data on reactions of murine macrophages with a variety of lectins, with special focus on Griffonia simplicifolia I-B4 isolectin, the only lectin we tried that distinguishes stimulated macrophages from resident populations. Specificity of Griffonia simplicifolia I reaction with carbohydrate determinants at the cell surface is shown by (i) ability of alpha-galactosidase treatment of intact cells to abolish all lectin binding whereas beta-galactosidase has no effect on lectin binding, (ii) ability of methyl alpha-D-galactopyranoside to completely inhibit lectin binding with methyl alpha-D-galactopyranoside having no effect on lectin binding, (iii) ability of brief treatment of intact cells with trypsin to liberate a glycopeptide but reacts with G. simplicifolia I to form a precipitate that is dissolved by addition of methyl-alpha-D-galactopyranoside or alpha-galactosidase, (iv) ability of methyl alpha-D-galactopyranoside (but no other monosaccharide) to completely inhibit avid binding of macrophages to G. simplicifolia I lectin immobilized on an insoluble support, and (v) ability of immobilized lectin to separate macrophages into highly pure subpopulations of lectin-reactive and lectin-unreactive cells, as shown by examination of fluorescein-labeled lectin-treated cells with phase-contrast/fluorescence microscopy.

Animals↗
PubMed1982

Relaxing and metabolic inhibitory action of X537A (Lasalocid) on the taenia of the guinea-pig caecum.

1. In the isolated guinea-pig taenia, application of X537A to the muscle caused a relaxation, while A23187 caused a sustained contraction. 2. Treatment with adrenergic blocking agents and tetrodotoxin had no effect on the relaxing response to X537A. 3. In the presence of a low concentration (10(-6) M) of X537A or under hypoxic conditions (bubbled with 95% N2: 5% CO2), the taenia lost the ability to respond to a high concentration (40 mM) of potassium with a sustained tonic contraction, although the rapid phasic contraction was still present. 4. When a low concentration of X537A was applied the shape of the contractile response to A23187 was changed from a sustained development of tension to an oscillatory tension which was also observed under hypoxia. 5. In tissues treated with glycerol for 3 weeks, neither X537A nor A23187 had any effect on the contractile response induced by elevation of calcium concentration (pCa = 4) in the presence of magnesium and ATP. 6. Exposure to a low concentration (10(-6) M) of X537A, or hypoxia, slightly yet significantly decreased the ATP content of the muscle. A high concentration (10(-5) M) of X537A markedly decreased the ATP content to about half normal. A23187 did not alter the ATP content. 7. Application of X537A did not alter the calcium content of the muscle and inhibited the A23187-induced increase in content. Under hypoxia, A23187 failed to increase the calcium content of the muscle. 8. The results indicate that, in contrast to A23187, X537A has a relaxing and metabolic inhibitory action on the guinea-pig taenia. The action of low concentrations of X537A resembled that of the hypoxia, indicating that X537A might exert its relaxing action, at least in part, by inhibition of aerobic energy metabolism of the muscle.

Adenosine Triphosphate↗
PubMed1982

Nature of anthopleurin-B-induced release of norepinephrine from adrenergic nerves.

Anthopleurin-B (AP-B), a new polypeptide from sea anemone (Anthopleura xanthogrammica), markedly increased the amount of norepinephrine (NA) released from the guinea pig isolated vas deferens. The AP-B-induced release of NA was inhibited or abolished by pretreatment with reserpine and by guanethidine or procaine but remained almost unaffected by mecamylamine. D 600, nifedipine, diltiazem, Mn2+, and Mg2+ markedly inhibited the NA releasing action of AP-B. The AP-B-induced release of NA increased in a linear fashion with increasing Na+ concentrations (85-150 mM). Also the NA release by AP-B increased with an increase in the concentration of external Ca2+ from 0 to 0.8 mM but decreased with an increase in the Ca2+ concentration from 0.8 to 2.0 mM. These results suggest that AP-B increases the permeability across the nerve cell membrane to both Na+ and Ca2+ and that this plays an important role in the NA release from the adrenergic nerve.

Adrenergic Fibers↗