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Query: UMLS:C0020538 (hypertension)
 170,190 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We studied the changes in pulmonary hemodynamics and lung wet weight induced with opsonized zymosan (OZ) in isolated guinea pig lungs perfused with Ringer-albumin solution containing neutrophils (PMNs). Addition of OZ to the PMN-perfused lungs caused pulmonary vasoconstriction and weight gain; neither OZ nor PMNs added individually to the perfusate altered pulmonary vasomotor tone or wet weight. The steady gain in lung weight by 1,588 +/- 464 mg over the 45-minute study period was associated with pulmonary capillary hypertension and an increase in the capillary filtration coefficient, indicative of increased lung vascular permeability. These responses may not be due to generation of oxygen radicals, because the alterations in pulmonary hemodynamics and lung weight were not reduced by addition of superoxide dismutase, catalase, or superoxide dismutase plus catalase. We examined the basis of the PMN-mediated effects by layering PMNs on bovine pulmonary artery endothelial monolayers. Challenge with OZ resulted in increased endothelial permeability to 125I-albumin. The monoclonal antibody IB4 (directed against CD18, the common beta-subunit of structurally related adhesion receptors on phagocytes, LFA-1, Mac-1, and P150,95) prevented the OZ-mediated increase in PMN adherence to endothelial cells and the increase in endothelial permeability to 125I-albumin. IB4 also inhibited the lung weight gain mediated by the OZ-stimulated PMNs in intact lungs. The protective effect of IB4 could be ascribed neither to inhibition of uptake of OZ by PMNs nor to inhibition of release of oxygen radicals, myeloperoxidase, and elastase.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Pulmonary edema induced by phagocytosing neutrophils. Protective effect of monoclonal antibody against phagocyte CD18 integrin. 197 52

The pattern of Evans blue extravasation in the brain in norepinephrine-induced acute hypertension is similar to our previous observations using horseradish peroxidase as a tracer. Pretreatment with flunarizine IV resulted in significant reduction of RISA leakage in all regions of the brains of acutely hypertensive rats. The reduction in RISA leakage in the drug-treated hypertensive group is not attributable to differences in the blood pressure elevations which were not significantly different in both groups. These studies suggest a role for calcium in the increased endothelial permeability occurring in cerebral vessels in acute hypertension. Further morphological studies are required to determine whether flunarizine reduces permeability by decreasing pinocytosis.
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PMID:Cerebrovascular permeability in acute hypertension: effect of flunarizine. 208 34

This ultracytochemical study was undertaken to determine whether increased arteriolar permeability in acute hypertension is accompanied by altered localisation of the ouabain-sensitive, K(+)-dependent p-nitrophenyl-phosphatase (K(+)-NPPase), a component of the Na+, K(+)-ATPase system. Rats were injected with horseradish peroxidase (HRP) intravenously and acute hypertension was induced by a 2-min infusion of angiotensin amide. Rats were killed at 3 and 15 min, following which brains were sliced and reacted for demonstration of K(+)-NPPase and HRP reaction product. Vessels of normotensive and hypertensive rats that were nonpermeable to HRP showed discontinuous distribution of K(+)-NPPase on the outer plasma membranes of endothelial and adventitial cells of arterioles and endothelial cells and pericytes of capillaries. Arterioles of the hypertensive rats which were permeable to HRP showed marked reduction of K(+)-NPPase localisation in their walls at 3 min while at 15 min when the blood pressure had returned to resting levels the enzyme localisation was similar to controls. This study demonstrates transient alteration of the NA+, K(+)-ATPase system during increased endothelial permeability in acute hypertension. The implication of this finding and our previous observation of reduced Ca2(+)-ATPase localisation in endothelial plasma membranes in acute hypertension has been discussed.
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PMID:Ultracytochemical localisation of Na+, K(+)-ATPase in cerebral endothelium in acute hypertension. 216 85

The association of HBV infection and glomerular damage was first reported by Combes et al in 1971, in a patient with nephrotic syndrome due to membranous glomerulopathy and chronic hepatitis B. Since, then, other glomerular diseases have been reported such as a) minimal changes nephropathy, b) IgA nephropathy, c) membranous-proliferative glomerulonephritis (MPGN), d) membranous, e) mesangial proliferative and f) lupus nephritis. All of them are associated with chronic hepatic disease and some of the following antigens: 1) HBsAg; 2) HBeAg; 3) HBcAg. These disorders are very frequent in Southeast Asia. Vertical transmission from mothers to fetuses may be important in maintaining the high carrier rate, and possibly plays a role in the development of glomerular damage. On the other hand, MPGN associated with HBsAg has rarely been reported and always with a favorable benign course. The present report describes interesting findings in a renal biopsy from a HBsAg and HBeAg carrier, who developed renal failure requiring hemodialysis. A 21 year old Korean man was admitted to the Hospital for nephrotic syndrome, microhematuria hypertension and renal failure. He had no previous history of blood transfusion, intravenous drug addiction, jaundice or liver disease. His father was HBsAg carrier with hepatic cirrhosis. An ultrasound examination showed normal renal size. Renal biopsy was performed and the patient received hemodialysis treatment. The specimen was processed for light microscopy, immunofluorescent studies and peroxidase-antiperoxidase technique. Frozen sections were studied by direct immunofluorescence for the identification of IgG, IgA, C1q, C3, fibrinogen and albumin. Paraffin sections stained by immunoperoxidase technique for HBsAg, using polyclonal monospecific rabbit anti-Human antisera (Dakopatts, Copenhagen).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Membranoproliferative glomerulonephritis with semilunar forms and massive deposits of IgA associated with HBsAg]. 229 14

Aneurysmal subarachnoid hemorrhage is associated with a sudden rise in intracranial pressure, acute arterial hypertension, and subarachnoid blood. The role that each of these factors may play in the development of the acute barrier disruption of the major cerebral arteries following subarachnoid hemorrhage was investigated in 42 rabbits. Horseradish peroxidase was given intravenously to assess the integrity of the barrier by transmission electron microscopy. Permeation of the tracer into the vessel was noted only in animals with increased intracranial pressure. A sudden rise in intracranial pressure is suggested to trigger acute barrier disruption following subarachnoid hemorrhage.
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PMID:Etiology of the disruption in blood-arterial wall barrier following experimental subarachnoid hemorrhage. 236 Jan 59

A monoclonal antibody to alpha-human atrial natriuretic polypeptide (alpha-hANP), KY-ANP-I, has been produced by fusion of a nonproducing mouse myeloma cell line, X63-Ag8.653, with spleen cells from BALB/c mice immunized with synthetic alpha-hANP conjugated to bovine thyroglobulin using the carbodiimide coupling procedure. Hybridomas were screened for antibody production by radioimmunoassay using culture media and 125I-alpha-hANP. They were cloned by the limiting dilution technique, expanded in culture, and injected intraperitoneally into BALB/c mice. The obtained antibody belonged to the immunoglobulin G1 subclass. Analysis by a Scatchard plot revealed a high affinity for alpha-hANP, with an association constant of 3.1 x 10(10) M-1. With this monoclonal antibody, a specific radioimmunoassay for alpha-hANP has been established. The antibody in mouse ascites was available for radioimmunoassay at a final dilution of 1:10(6). Values of IC10 and IC50 in this radioimmunoassay were 3 and 30 fmol/tube, respectively. The radioimmunoassay showed a cross-reactivity of 0.9% with alpha-rat ANP. alpha-hANP-(8-22) and alpha-ANP-(1-6) exhibited less cross-reactivity than alpha-rat ANP on a molar basis. There was no cross-reaction with alpha-ANP-(17-28). Thus, the recognized epitope must be located in the N-terminal half of the ring structure of alpha-hANP including Met12 residue. This radioimmunoassay could detect gamma-hANP and beta-hANP as well as alpha-hANP. The monoclonal antibody was also useful for immunohistochemical studies. ANP-positive cells were finely stained in the human atrium using the avidin-biotin-peroxidase complex technique.(ABSTRACT TRUNCATED AT 250 WORDS)
Hypertension 1988 Aug
PMID:A monoclonal antibody to alpha-human atrial natriuretic polypeptide. 245 52

Wheat germ agglutinin-horseradish peroxidase (WGA-HRP) injections were made at sites within a restricted portion of the midbrain periaqueductal grey region (PAG) of the cat at which microinjection of the excitant amino acid, D.L-homocysteic acid, elicits the strongest form of a defence reaction, including a hypertensive response. Among the revealed projections, significant anterograde labelling was found in a discrete region of the rostral ventrolateral medulla, the subretrofacial nucleus (SRF). In the cat, the SRF contains pressor neurones which project to the spinal preganglionic sympathetic outflow. The labelling was most marked ipsilaterally, although substantial contralateral labelling was also observed. To verify that the projection to the SRF originated from the restricted 'defence region' of the PAG, WGA-HRP or rhodamine-labelled microspheres were injected into physiologically-identified sites in the SRF. In all experiments, labelled neurones were found in the same restricted region of the PAG at which DLH injection evokes hypertension and behavioural signs of the defence reaction. The results are consistent with the hypothesis that a discrete cell group within the PAG mediates both somatic and autonomic components of the defence reaction and that the characteristic hypertensive response is mediated by a direct pathway from these PAG cells to pressor neurones in the SRF.
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PMID:Anatomical evidence that hypertension associated with the defence reaction in the cat is mediated by a direct projection from a restricted portion of the midbrain periaqueductal grey to the subretrofacial nucleus of the medulla. 246 61

The area postrema is a circumventricular organ that plays an important role in neurohumoral regulation of the circulation. We have developed a method to examine permeability and vascular responses of the microcirculation of the area postrema in vivo. A craniotomy was performed over the dorsal brain stem in anesthetized rats, and blood vessels to the area postrema were visualized with fluorescein microscopy. Extravasation of sodium fluorescein (MW, 386), but not 150 kDa (MW) fluorescein isothiocyanate-dextran, occurred in the area postrema under control conditions. There was no extravasation of fluorescein or dextran in the brain stem under control conditions. Acute hypertension produced marked disruption of the barrier to 150 kDa dextran in the area postrema, compared with minimal disruption in the brain stem. We tested the hypothesis that the area postrema has greater permeability to small molecules than the brain stem and that this permeability might be accompanied by distinctive vascular responses. Topical suffusion of adenosine and ADP produced similar dose-related dilation of arterioles to area postrema and dorsal brain stem. Topical and intravenous vasopressin produced similar dose-related constriction of vessels to area postrema and brain stem. Electron microscopy in rats demonstrated that a barrier to horseradish peroxidase, which is absent in capillaries in the area postrema, is present in arterioles that supply the area postrema.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Microcirculation of the area postrema. Permeability and vascular responses. 275 49

The plasma membrane calcium-activated adenosine triphosphatase (Ca2+-ATPase) is known to regulate intracellular calcium levels. This enzyme was localised in intracerebral cortical vessels of normotensive and acutely hypertensive rats. Of interest was whether the arterioles that develop increased permeability to horseradish peroxidase (HRP) in acute hypertension demonstrate any alteration in localisation of Ca2+-ATPase as compared to normotensive controls. Rats were injected with HRP intravenously and acute hypertension was induced by a 2-min infusion of angiotensin amide. Following perfusion of fixative, brains were sliced and reacted for demonstration of HRP reaction product and Ca2+-ATPase. Normotensive rats showed discontinuous distribution of Ca2+-ATPase on the outer plasma membranes of endothelial, smooth muscle and adventitial cells of arterioles. The localisation of Ca2+-ATPase in pinocytotic vesicles present in endothelial and smooth muscle cells was quite striking. Focal cortical areas of hypertensive rats showed increased arteriolar permeability to HRP. Permeable arterioles showed marked reduction of Ca2+-ATPase on the outer plasma membranes of endothelium and smooth muscle cells as compared to nonpermeable arterioles of the same animals and arterioles of normotensive controls. The latter finding suggests that calcium may be involved in increased cerebrovascular permeability mechanisms in acute hypertension.
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PMID:Localisation of calcium-activated adenosine-triphosphatase (Ca2+-ATPase) in intracerebral arterioles in acute hypertension. 296 18

Hypertension in chronic renal failure is usually due to excessive accumulation of salt and water. In some cases, sodium and volume depletion by dialysis fail to reduce the high BP, and plasma renin activity tends to be higher. We performed a semiquantitative analysis of the immunohistochemical distribution of renin in the kidneys of ten patients with end-stage renal disease and hypertension using a specific antihuman renin antibody and a peroxidase-antiperoxidase technique on paraffin sections of nephrectomy and/or autopsy specimens. In five cases with severe, dialysis-resistant hypertension, the degree of immunoreactivity was most striking, exceeding that found in renovascular hypertension and present in arterioles at a distance from the glomeruli. Three cases of advanced diabetic glomerulosclerosis consistently showed minimal immunoreactivity. We conclude that renin often can be detected immunologically in the kidney of patients with chronic renal failure and hypertension, but its pathophysiological role will require further study.
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PMID:Immunohistochemical localization of renin in end-stage kidneys. 304 41


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