Search PubMed⌕ Search

Biomedical subjects

M Takata

Publications and source records attributed to M Takata.

At least 289 records · Page 16Linked to original sources
PubMed1986

Cardiovascular effects of ketanserin in conscious rabbits.

The antihypertensive effects of intravenous injection of ketanserin, a 5-HT2 receptor antagonist, were assessed in conscious rabbits. In intact rabbits, ketanserin lowered blood pressure in a dose-dependent manner. The antihypertensive effects of ketanserin were also observed in rabbits with two-kidney, one clip (2K1C) hypertension and with one-kidney, one clip (1K1C) hypertension. The effect was more marked in the 1K1C rabbits with low plasma renin activity (PRA) and high plasma norepinephrine (PNE) than in 2K1C rabbits with high PRA and normal PNE. The heart rate was not changed. Ketanserin suppressed the pressor response to exogenous norepinephrine (0.6 micrograms/Kg) 15, 30 and 45 min after the injection of ketanserin (1 mg/Kg). It also suppressed the pressor response to phenylephrine (3 micrograms/Kg) 15 min after the injection, but it did not suppress the pressor response to angiotensin II (0.15 micrograms/Kg). In order to investigate baroreceptor function, balloons were placed around the abdominal aorta and the inferior vena cava and inflated alternately. Thus, the mean arterial pressure vs heart period-logistic curve was obtained under steady-state conditions. There were no changes after the drug administration in the range of heart period and the gain (the slope at midpoint of the curve). These results suggest that the inhibition of pressor response of norepinephrine has effects in addition to a direct vasodilatory action and that an alteration of baroreceptor function is not involved in the antihypertensive effects of ketanserin.

Animals↗
PubMed1985

Familial aggregation of red blood cell cation transport systems in Japanese families.

The rate of lithium, sodium, and potassium transport in red blood cells is thought to be associated with essential hypertension. In order to investigate the contribution of genetic and environmental factors to cation transport, their correlation was analyzed in 60 parent-offspring pairs and 17 husband-wife pairs in Toyama City, Japan. Lithium-sodium countertransport and sodium-potassium cotransport rates were significantly correlated in parent-offspring pairs (r = 0.52, p less than 0.01 and r = 0.46, p less than 0.01, respectively) but not in husband-wife pairs. Sodium pump rates were significantly correlated in both pairs (r = 0.48, p less than 0.01 in parent-offspring pairs, r = 0.46, p less than 0.05 in husband-wife pairs). Therefore, lithium-sodium countertransport and sodium-potassium cotransport were found to have a substantial genetic component and the sodium pump to have a substantial environmental component. Sodium pump rates were significantly correlated with sodium/creatinine (r = 0.21, p less than 0.05) and sodium/potassium (r = 0.32, p less than 0.01) in casual urine.

Adult↗
PubMed1985

Glomerular deposition of IgA in experimental hepatic cirrhosis.

Wistar rats rendered cirrhotic with carbon tetrachloride excreted significant proteinuria and hematuria. Serum levels of IgA and IgG were significantly elevated in cirrhotic animals. They showed mild mesangial proliferation and immunofluorescent studies revealed deposits of IgA and IgG predominantly in mesangial areas and along capillary walls. These findings were very similar to those seen in patients with hepatic cirrhosis or IgA nephropathy. The deposits of IgA were also found in hepatic tissue from cirrhotic animals. The intensity and distribution of glomerular IgA deposits were not diminished after treatment with acid buffer. These results suggest that glomerular IgA are IgA polymers and decreased hepatic clearance of hepatic IgA polymers may be responsible for the glomerular deposition of IgA.

Animals↗
PubMed1985

Membranous glomerulonephritis associated with enterococcal endocarditis.

An autopsy case of membranous glomerulonephritis associated with enterococcal endocarditis was reported. Although enterococcal antigen was not identified in glomerular deposits, the eluate from the patient's renal tissue was shown to specifically recombine with cells of the enterococcus isolated from his own ante mortem blood. Hypocomplementemia, circulating immune complexes and antienterococcal antibodies were also observed. These findings suggest that enterococcus-related immune complexes played a role in the pathogenesis of glomerulonephritis associated with enterococcal endocarditis in this patient.

Aged↗
PubMed1985

Acute interstitial nephritis with bone marrow granulomas and uveitis.

A case of interstitial nephritis with bone marrow granulomas and uveitis was presented. A 53-year-old woman was found to be uremic in the course of rheumatoid arthritis. The renal biopsy revealed acute interstitial nephritis with eosinophilic infiltration. She also had bone marrow granulomas and uveitis. These findings were compatible with those of the syndrome described by Dobrin et al. The etiology and the pathogenesis of this syndrome remain unknown. However, the elevation of the erythrocyte sedimentation rate, raised levels of serum immunoglobulins, presence of circulating immune complexes and decreased T-cell population observed in this patient suggest the involvement of immunological disorders.

Acute Disease↗
PubMed1984

Cortically induced postsynaptic potentials in hypoglossal motoneurons after axotomy.

Cortically induced postsynaptic potentials were studied in normal and axotomized cat hypoglossal motoneurons. In normal protruder motoneurons innervating tongue protruder muscles, we have demonstrated that stimulation of the orbital gyrus, at the point optimum for inducing lapping movements of the tongue by repetitive stimuli, produced inhibitory postsynaptic potentials or excitatory postsynaptic potentials followed by predominant inhibitory postsynaptic potentials. The cortically induced excitatory postsynaptic potential in normal protruder motoneurons was composed of only the short-latency component. In protruder motoneurons 30, 40, 60 and 80 days after axotomy, we have demonstrated that the number of protruder motoneurons responding with two components of excitatory postsynaptic potentials (the short- and the long-latency component) to cortical stimulation increased in correspondence with the lapse of days after axotomy and that the amplitude of cortically induced inhibitory postsynaptic potentials in axotomized protruder motoneurons was reduced in size as compared with normal protruder motoneurons.

Animals↗
PubMed1984

Effects of captopril on the renal hemodynamics during aprotinin infusion in anesthetized dogs.

The effect of captopril (SQ 14,225) on the renal hemodynamics, cortical plasma flow (CPF) and noncortical plasma flow (NCPF), was studied in sodium-replete anesthetized dogs during aprotinin infusion. Mean blood pressure (MBP) increased by aprotinin (p less than 0.05) and decreased by captopril (p less than 0.02). Renal vascular resistance (RVR) tended to increase by aprotinin and decreased from 1.29 to 0.86 mm Hg/ml/h (74.7%) by captopril (p less than 0.05). Renal vein renin activity (RRA) inclined to decrease by aprotinin and increased from 17.8 to 47.2 ng/ml/h (278.2%) by captopril (p less than 0.05). Although the administration of captopril alone did not alter the renal hemodynamics despite the reduction of MBP, captopril made a recovery of renal plasma flow (RPF), CPF and NCPF which had decreased by aprotinin. Especially, CPF showed a significant recovery from 45.4 to 55.6 ml/min (123.6%) by captopril (p less than 0.02). These results indicate that the inhibition of endogenous angiotensin made a preferential increase in CPF and suggest that the renin-angiotensin system plays a major role in the effect of captopril of the renal hemodynamic changes.

Anesthesia, General↗
PubMed1984

Heritability of erythrocyte Na+-Li+ countertransport in relation to essential hypertension.

The Na+-Li+ countertransport system in erythrocytes was investigated in patients with essential hypertension and control subjects. Furthermore, studies on the pairs of parent-offspring and husband-wife were added in order to evaluate heritability of the countertransport. The Na+-Li+ countertransport of patients with essential hypertension and normotensive subjects with the family history of hypertension was significantly increased in comparison with that of normotensive subjects without the family history. The correlation coefficient of the countertransport in pairs of parent-offspring was significant but not between husband-wife. These results support the concept of a genetic determinant for the countertransport system.

Adult↗
PubMed1983

Correlations among culture times, sugar composition and biological activities of Sporothrix schenckii antigens.

Glycoproteins were isolated by ethanol precipitation, Con A-sepharose 4B and DEAE-sephadex A-50 chromatography from culture filtrates of Sporothrix schenckii ATCC 10268 at incubation periods of 2, 7, and 14 days, and their chemical and immunological properties investigated. Sugar composition of the isolated glycoproteins varied with time of culture, i.e. from mostly mannose on the 2nd day of culture to increasing amounts of rhamnose and small amounts of galactose in addition to mannose on the 7th and 14th day. The changes in sugar composition also were observed to be closely related to the growth morphology of the organisms. The isolated glycoproteins showed different serological reactivity in immunodiffusion tests against rabbit anti-S. schenckii antiserum. In addition, they showed varying degree of cross-reaction with rabbit anti-Klebsiella pneumoniae K47, anti-Cladosporium werneckii and anti-Saccharomyces cerevisiae antisera. The immunodiffusion results correlate well with sugar composition and strongly suggest the possibility that rhamnose, galactose and mannose determinants participate in the serological reaction of S. schenckii. In delayed hypersensitivity skin tests in guinea pigs immunized with S. schenckii, only Con A-binding glycoproteins were reactive. These fractions also resembled each other in amino acid content. The results from the present work indicate that the immunochemical properties of S. schenckii glycoproteins vary with incubation period, and suggest the need for standardization of sporotrichin test antigens.

Amino Acids↗
PubMed1983

Synaptic efficacy of inhibitory synapses in hypoglossal motoneurons after transection of the hypoglossal nerves.

In cat hypoglossal motoneurons after axotomy the synaptic efficacy of inhibitory synapses made by the lingual nerve afferent fibers was studied. The amplitude of the short- and the long-lasting inhibitory postsynaptic potential produced in tongue protruder motoneurons 24 days after axotomy by stimulation of the lingual nerve was significantly reduced in size as compared with the control on the unoperated side. In most protruder motoneurons 40 days after axotomy a large excitatory postsynaptic potential and a spike was produced by stimulation of either the ipsilateral or the contralateral lingual nerve. We have demonstrated that the decline of synaptic efficacy of inhibitory synapses for the short-lasting inhibitory postsynaptic potential was more prominent than that for the long-lasting inhibitory potential in the motoneuron 24 days after axotomy. After the cut axons of protruder motoneurons were re-united to tongue muscles, we have demonstrated that the decline of synaptic efficacy of inhibitory synapses for the short-lasting inhibitory postsynaptic potential was less prominent than that in axotomized protruder motoneurons.

Animals↗
PubMed1983

Coexistence of hyperplasia of renomedullary interstitial cells and juxtaglomerular cells after acute occlusion of renal artery.

A left renal artery aneurysm was found in a 45-year-old normotensive man. In an attempt to evade the possible occurrence of aneurysmal rupture, aneurysmectomy in addition to left renal biopsy (first surgery) was performed. This vascular operation led to a virtually complete renal artery stenosis concomitant with the development of hypertension. The renin-angiotensin-aldosterone system and levels of plasma prostaglandins were also increased following this failed surgery. Reconstruction of the affected renal artery was technically so difficult that left nephrectomy was carried out (second surgery). Renal specimens obtained at the first surgery revealed no histological abnormalities. Discriminating histological findings of the kidney obtained at the second surgery were remarkable; hyperplasia of the juxtaglomerular cells producing renin and hyperplasia of the renomedullary interstitial cells which had pecularities similar to cells known to secrete renal prostaglandins. High levels of the renin-angiotensin-aldosterone system and plasma prostaglandins after the first surgery were reduced following the second surgery. It is suggested that acute constriction of the renal artery led to a hyperplastic change of the juxtaglomerular cells and the renomedullary interstitial cells and stimulated an inappropriate release of renin and renal prostaglandins.

Acute Disease↗