PubMed Health⌕ Search

Biomedical subjects

I Inoue

Publications and source records attributed to I Inoue.

At least 145 records · Page 8Linked to original sources
PubMed1992

Induction of irreversible glomerulosclerosis in the rat by repeated injections of a monoclonal anti-Thy-1.1 antibody.

The present experiment demonstrated that an irreversible glomerulosclerosis could be induced in the rat through repeated intravenous administrations of OX-7 (a monoclonal anti-Thy-1.1 antibody). Rats were injected with 0.2 mg of affinity-purified OX-7 at 1-week intervals for a period of 4 weeks. Glomerular damage was periodically examined at light-microscopic level. Thirty-five days after the initial injection (7 days after the final injection), capillary aneurysms and expansion of the mesangial areas with hypercellularity were frequently observed. Similar glomerular damage was also observed in rats 7 days after they received a single injection of either 1.0 or 0.2 mg of OX-7. After repeated injections, 112 days from the initial administration (84 days after the final injection), approximately 60% of the glomeruli had expanded mesangial areas with an apparent increase in the mesangial matrix. The result contrasts sharply with that obtained from a single injection of OX-7 in that more than 85% of the glomeruli showed no abnormalities 84 days after the injection. This chronic model, as a result of repeated injections of the antibody, could serve as a potential for further investigation of the mechanisms involved in the development of chronic glomerulonephritis.

Animals↗
PubMed1992

Endothelin blocks ATP-sensitive K+ channels and depolarizes smooth muscle cells of porcine coronary artery.

ATP-sensitive K+ channels with a conductance of 30 pS in smooth muscle cells of porcine coronary artery were found to be highly active in the intact cell-attached patch configuration when the pipette contained a physiological concentration of Ca2+ (greater than 10(-4) M). In the inside-out configuration, these channels were activated by extracellular Ca2+ and blocked by cytosolic ATP and glibenclamide. Endothelin applied to the pipette specifically blocked these channels in a concentration-dependent manner in the cell-attached configuration (half-maximal inhibition, 1.3 x 10(-9) M). A K+ channel opener, nicorandil, activated these channels even in the presence of 10(-8) M endothelin. In the whole-cell current-clamp method, the cell membrane was depolarized by endothelin and then repolarized by nicorandil. The membrane depolarization is closely related to contraction of smooth muscle cells. These results suggest that the ATP-sensitive K+ channels are important in controlling the vascular tone of the coronary artery and that endothelin can increase vascular tone by blocking these channels.

Adenosine Triphosphate↗
PubMed1992

Apolipoprotein E prevents the progression of atherosclerosis in Watanabe heritable hyperlipidemic rabbits.

Apo E plays an important role in plasma lipoprotein metabolism through its high affinity binding to cell surface LDL receptor. In the present study, we studied the effects of apo E on the atherogenic process in Watanabe heritable hyperlipidemic rabbits which are deficient in LDL receptor and an animal model for familial hypercholesterolemia. We isolated apo E from plasma of 1% cholesterol-fed rabbits and administered 10 mg of purified apo E intravenously into five Watanabe heritable hyperlipidemic rabbits three times a week from their age of 2.5 months to 11 months for 8.5 months. After sustained administration to apo E, we found a significant reduction in the accumulation of cholesterol ester in aortae (1.55 +/- 0.07 mg/g tissue) as compared to control rabbits (4.32 +/- 0.61 mg/g tissue). Supporting this, the percentage of the surface area of the aorta with macroscopic plaque was remarkably decreased in apo E-treated animals (18.8 +/- 5.1% vs. 38.8 +/- 8.0% in control). Thus, apo E definitely prevented the progression of atherosclerosis in Watanabe heritable hyperlipidemic rabbits.

Animals↗
PubMed1992

Patch-clamp analysis of the effects of the insecticide deltamethrin on insect neurones.

1. The mode of action of the pyrethroid insecticide deltamethrin on inexcitable embryonic cultured cockroach neurones has been investigated using the patch-clamp technique. 2. Whole-cell recordings of the current induced by step depolarizations of the cell membrane showed that concentrations of deltamethrin ranging from 10(-8) to 5 x 10(-6) mol l-1 induced a small tetrodotoxin (TTX)-sensitive inward current that peaked at around +10 mV and reversed at around +60 mV. The activation and inactivation kinetics of this current were much slower than those of the axonal sodium current in this same species and were relatively insensitive to membrane potential. Steady-state inactivation was almost absent. 3. Single-channel activity associated with the action of the insecticide was analyzed using the cell-attached configuration. Three distinct patterns of activity were found: (1) discrete single-channel events of relatively short duration, (2) long events of comparatively small amplitude and (3) complex bursts made up of a succession of openings and closings to several levels. These three patterns were analyzed quantitatively using specially designed programs. 4. The first pattern of activity could be seen in most patches. It consisted of short (1-10 ms) rectangular events of comparatively small amplitude (1.5 pA at rest) and very low open time probability (around 0.001). The current-voltage relationship of these small events was linear over the voltage range studied and the (extrapolated) reversal potential approximated ENa. 5. The second pattern of activity was observed less frequently. The channels could stay open for very long periods (up to several seconds) and occasionally flickered between two or more levels. 6. The third pattern of activity was observed in many patches. During the burst, which could last from a few milliseconds to a few hundred milliseconds, the single-channel current jumped almost continuously between several levels (up to 7 or 8).

Animals↗
PubMed1992

Can high blood pressure alone increase erythrocytic intracellular sodium concentration?

In order to clarify the direct effects of high blood pressure on erythrocytic intracellular sodium concentration ([Na+]i) and sodium transport systems, a static pressure of 2.5 atm was applied to whole blood in plastic syringes at room temperature for 5 and 24 h. In the control samples, 5 h incubation under atmospheric pressure produced a significant decrease in ouabain-sensitive Na(+)-K+ pump activity and plasma pH, but no change in other parameters. After 24 h incubation, [Na+]i and mean corpuscular volume were significantly increased and intracellular potassium concentration, ouabain-sensitive Na(+)-K+ pump activity, and plasma pH were decreased. The change in [Na+]i during incubation under atmospheric pressure may be due to the increased permeability of the cell membrane and the decrease in ouabain-sensitive Na(+)-K+ pump activity. The pressure load did not increase erythrocytic [Na+]i but did decrease it relative to the control. The pressure load had no apparent effects on sodium transport systems, mean corpuscular volume and pH of plasma relative to the control. Although the mechanisms of the effect of pressure load on [Na+]i were not determined, we did find that high blood pressure alone was unable to increase erythrocytic [Na+]i.

Adult↗
PubMed1992

Analysis of IgA antibody to Pseudomonas aeruginosa in sera and sputa of patients with chronic airway diseases.

The change of IgA system for Pseudomonas infection was examined by enzyme-linked immunosorbent assay of the system in sera and sputa of patients with chronic airway diseases. The anti-Pseudomonas total IgA antibody titers in both sera and sputa were not elevated in group I with no infection (mainly chronic bronchitis) and group II infected with bacteria other than Pseudomonas, but were elevated in group III colonized transiently with Pseudomonas [diffuse panbronchiolitis (DPB) and bronchiectasis] and group IV colonized persistently with Pseudomonas (mainly DPB). The elevation in the sera and sputa were mainly due to monomeric IgA and polymeric IgA (S-IgA), respectively, and values were significantly higher in group III than in group IV only in the sera. These results indicate that the IgA system is enhanced in advanced DPB and bronchiectasis complicated by Pseudomonas infection, and that the anti-Pseudomonas IgA antibody titer in serum is more useful than that in sputum for the diagnosis of respiratory Pseudomonas infection.

Adult↗
PubMed1992

Cell profile and elastase activity in diffuse panbronchiolitis investigated by bronchoalveolar and bronchial lavage.

To examine the mechanism of tissue damage which causes bronchiolectasis in diffuse panbronchiolitis (DPB), the cellular components, elastase and its main inhibitor, alpha 1-protease inhibitor (alpha 1-PI) were measured in bronchoalveolar and bronchial lavage fluid (BALF and BLF) from 14 DPB patients. A predominant increase in the neutrophil count was observed in DPB. Elastase activity in BALF and BLF was about 1,000-fold higher in the DPB group than in the control group. An inhibitor study and a positive correlation between elastase activity and the neutrophil count in both lavage fluids from the DPB group indicated that the activity was mainly that of neutrophil elastase. Western blot analysis of alpha 1-PI showed that most of the alpha 1-PI in the lavage fluids from DPB group was degraded. These results indicated that neutrophil infiltration increases the level of elastase in the DPB lesions; this increase seems to be closely related to tissue damage.

Adult↗
PubMed1991

ATP-sensitive K+ channel in the mitochondrial inner membrane.

Mitochondria take up and extrude various inorganic and organic ions, as well as larger substances such as proteins. The technique of patch clamping should provide real-time information on such transport and on energy transduction in oxidative phosphorylation. It has been applied to detect microscopic currents from mitochondrial membranes and conductances of ion channels in the 5-1,000 pS range in the outer and inner membranes. These pores are not, however, selective for particular ions. Here we use fused giant mitoplasts prepared from rat liver mitochondria to identify a small conductance channel highly selective for K+ in the inner mitochondrial membrane. This channel can be reversibly inactivated by ATP applied to the matrix side under inside-out patch configuration; it is also inhibited by 4-aminopyridine and by glybenclamide. The slope conductance of the unitary currents measured at negative membrane potentials was 9.7 +/- 1.0 pS (mean +/- s.d., n = 6) when the pipette solution contained 100 mM K+ and the bathing solution 33.3 mM K+. Our results indicate that mitochondria depolarize by generating a K+ conductance when ATP in the matrix is deficient.

Adenosine Triphosphate↗
PubMed1991

Micromolar concentrations of veratridine activate sodium channels in embryonic cockroach neurones in culture.

The mode of action of the alkaloid veratridine has been reinvestigated on cultured cockroach neurones, which are normally inexcitable and do not have a detectable fast sodium current. The whole-cell and cell-attached configurations of the patch-clamp technique were used to record the macroscopic and single channel currents, respectively. Concentrations of veratridine ranging from 10(-8) to 10(-5) M were found to induce a small tetrodotoxin (TTX)-sensitive inward current, which peaked around +10 mV and reversed around +55 mV. This current exhibited a pronounced plateau and was insensitive to changes in the holding potential. Bath application of veratridine induced typical TTX-sensitive inwardly-directed single-channel activity, falling into two (apparently coupled) categories of events: first, relatively large events (1 pA at a hyperpolarized potential of -125 mV relative to rest) of short duration and, second, small bursting events (0.4 pA under similar conditions) of slightly longer duration. Pipette application of similar concentrations of veratridine had similar effects in that two categories of events were observed: first, bursts of large events with multiple conductance states and, second, small events of very long duration. The current/voltage relationship of these events was linear for the voltage range studied and the (extrapolated) reversal potential approximated +110 mV. These results support the hypothesis that veratridine, in small concentrations, induces a slow voltage-dependent activation of TTX-sensitive sodium channels, independent of the fast activating and inactivating sodium channels involved in action potential generation.

Animals↗
PubMed1991

Detection of human leucocytes by cyclic voltammetry and its application to monitoring of allergic reaction.

Cyclic voltammetry was applied to the detection of human leucocytes and the monitoring of allergic reactions. A basal plane pyrolytic graphite electrode with attached leucocytes on a porous nitrocellulose membrane filter was employed as a working electrode. An anodic peak current appeared at 0.33 V versus the saturated calomel electrode (SCE) when the potential of the working electrode was scanned in the range of 0-1.0 V versus SCE. This peak current was attributed to the electrochemical oxidation of serotonin. When egg white was added to leucocytes obtained from patients who were allergic to egg, the peak current decreased owing to degranulation of leucocytes leading to serotonin release. The peak current decreased with increasing allergen concentration in the range of 5-50 micrograms ml-1. Leucocytes did not respond to other allergens such as soybean, milk and dinitrophenylated bovine serum albumin (DNP-BSA).

Adult↗
PubMed1991

Significance of intracellular free calcium and magnesium and calcium-regulating hormones with sodium chloride loading in patients with essential hypertension.

This study was designed: (1) to test the hypothesis that the pressor response to sodium chloride loading in patients with essential hypertension is associated with disorder of divalent cations (calcium and magnesium); and (2) to clarify the relationship between intracellular free calcium concentration and serum levels of calcium-regulating factors and intracellular magnesium concentration. With sodium chloride loading, mean blood pressure, urinary calcium and magnesium excretions and platelet calcium concentration were increased, and serum total and ionized calcium, magnesium concentrations and erythrocyte magnesium concentration were decreased. Change in mean blood pressure was correlated with changes in parathyroid hormone (r = 0.49, P less than 0.05), serum total and ionized calcium (r = -0.50, P less than 0.05) and erythrocyte magnesium (r = -0.56, P less than 0.05) and platelet calcium concentrations (r = 0.46, P less than 0.05). In addition, change in platelet calcium concentration was related to changes in parathyroid hormone (r = 0.44, P = 0.05), serum total and ionized calcium (r = -0.66, P less than 0.01) and erythrocyte magnesium concentration (r = -0.49, P less than 0.05). It is concluded that the pressor effect of excessive sodium chloride intake on blood pressure in patients with essential hypertension is associated with a disorder of divalent cations and that alteration of the intracellular free calcium concentration with sodium chloride loading may occur through handling of serum total and ionized calcium, parathyroid hormone and/or intracellular magnesium concentration.

Adult↗
PubMed1991

Role of intracellular cation abnormalities in development of left ventricular hypertrophy.

To elucidate factors determining the development of left ventricular hypertrophy, we performed measurements of intraerythrocyte sodium and intraplatelet calcium concentrations, measurements of plasma and urinary catecholamine levels and plasma renin activity, calculation of left ventricular mass using echocardiography, and 24-h ambulatory blood pressure (BP) monitoring. The results indicate that abnormalities of sodium and calcium mobilization may play an important role in the adaptation of left ventricular muscle to a persistent increase in BP.

Adult↗
PubMed1991

Deterioration of immune complex solubilization activity of serum by increased concentration of factor D.

We investigated the effect of excess complement factor D on the immune complex solubilization activity (ICSA) of serum. First, we estimated the concentration of factor D, ICSA and the hemolytic activity via the classical complement pathway (CH50) in the sera of 16 healthy individuals and 36 patients on hemodialysis for end-stage renal failure. The serum concentration of factor D in these patients (mean +/- SD: 12.12 +/- 2.38 micrograms/ml) was significantly higher (p less than 0.001) than that in the healthy subjects (1.02 +/- 0.11 micrograms/ml). In this study, peroxidase and antiperoxidase rabbit IgG were used as immune precipitates for ICSA. The ICSA in patients (45.8 +/- 7.4 normal human serum %, NHS%) was significantly lower (p less than 0.001) than that in the healthy subjects (100.2 +/- 12.5 NHS%). There was no difference in CH50 between the sera of the patients (31.8 +/- 2.5) and that of the healthy group (32.4 +/- 2.6). Second, we determined that increasing amounts of purified factor D added to fresh serum resulted in a decrease in ICSA. This occurred in the serum of a healthy individual as well as in that of a patient. CH50 did not change regardless of the concentration of factor D used. There was an increase in C3 conversion in the sera to which purified factor D had been added, as observed by crossed immunoelectrophoresis. It is suggested that ICSA had deteriorated due to the excess of factor D, which had activated the alternative pathway of complement.

Antigen-Antibody Complex↗
PubMed1991

Significance of intracellular cations and calcium-regulating hormones on salt sensitivity in patients with essential hypertension.

Although the existence of salt sensitivity in essential hypertensives has been well known, the precise mechanism(s) has not yet been elucidated. The aim of this study was to clarify the relation between the responses in blood pressure, extra- and intracellular cations and calcium-regulating hormones to oral NaCl loading in essential hypertensives. After oral NaCl loading, mean blood pressure, urinary excretions of calcium and magnesium, and PLT[Ca2+]i were significantly increased. [Ca2+]o and E[Mg]i were decreased. The changes (delta) in mean blood pressure by NaCl loading positively correlated with delta PLT[Ca2+]i and delta PTH, and negatively with delta[Ca2+]o and delta E[Mg]i. Delta PLT[Ca2+]i positively correlated with delta PTH and negatively with delta[Ca2+]o and delta E[Mg]i. From these results, the blood pressure response to oral NaCl loading is associated with the alternation of [Ca2+]i metabolism in which the changes in magnesium metabolism and calcium-regulating hormones may be involved.

Adult↗