Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0020538 (hypertension)
 170,190 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

One week after hypertension was produced in male Wistar rats (150 g body weight) by a complete aortic ligature placed between renal arteries, electron microscopic studies showed a striking increase of cytoplasmic microfilaments in the endothelial cells of the aortic segment above coarctation (mean blood pressure 160 mm Hg). These microfilaments measured 40-70 A in diameter and were located particularly close to the endothelial clefts. In "en face" preparation of aortic endothelial cells treated with antiactin autoantibodies (AAA) followed by antihuman IgG, the cells above the ligature of hypertensive animals were intensely fluorescent compared with those of the aortic portion below the ligature or that of controls. The fluorescence was abolished after incubating the AAA-containing sera with thrombosthenin-A, suggesting the presence of actin. There was also an increase transport of horseradish peroxidase and ferritin through the endothelial cell layer. While endothelial cells so modified may play a role in permeability regulation, they may also be related to such mechanisms as electronic coupling and synchronized contraction of aortic cells during hypertension.
 ...
PMID:Contractile apparatus in aortic endothelium of hypertensive rat. 120 6

Kidney biopsy specimens obtained from a group of individuals with chronic glomerulonephritis (CGN) have been processed for light and electron microscopic immunolocalization of total immunoglobulins (Igs). In a few cases, acid phosphatase (ACPase), a lysosomal enzyme marker, was ultrastructurally visualized. In the glomeruli, horseradish peroxidase-stained Igs were revealed in capillary lumina, urinary spaces and in transit through occasional loci of the glomerular basal membranes while ACPase-containing lysosomes resided both within and outside the cells. In the proximal tubules, Igs were traced in the endocytic vesicles and vacuoles, the latter also being positive for ACPase. Statistically significant relationships have been revealed between the number of IGs-labeled proximal tubules and some clinical or pathomorphological stigmata of CGN, in particular, proteinuria and arterial hypertension levels, marked interstitial sclerosis, etc. The data obtained are discussed in regard to the mechanisms of increased macromolecular filtration and the different proteinuria selectivity levels as well as the development of interstitial sclerosis as a result of the elevated reabsorption and incomplete lysosomal degradation of Igs in CGN.
 ...
PMID:[Immunoglobulin filtration and reabsorption as possible factors in the pathogenesis of chronic glomerulonephritis. Clinical, immunomorphological and histoenzymological research]. 144 Mar 30

There are many unanswered questions about chronic glaucoma which cannot be investigated in the available animal models. The present experiments were designed to develop a rabbit model of chronic intraocular hypertension with characteristics similar to human chronic glaucoma by ligating vortex veins or by making single or multiple intraocular injections of 0.5% or 1% alpha-chymotrypsin, 20% chondroitin sulphate, 2% hydroxypropyl methylcellulose, 2% sodium carboxymethylcellulose or 1% or 2% methylcellulose. Evaluation was based on the clinical findings, intraocular pressure and the retrograde axoplasmic transport function of the optic nerve using a horseradish peroxidase histochemical technique. Most methods either failed to produce moderate chronic intraocular hypertension or were associated with other complications. However, a reliable and relatively long period (eight weeks) of intraocular hypertension was developed by a series of four intra-anterior chamber injections of 1% or 2% methylcellulose. This model has been proved suitable for the study of structural and functional damage to the retina and optic nerve caused by chronic glaucoma.
 ...
PMID:Development of experimental chronic intraocular hypertension in the rabbit. 144 75

The dendritic complexity of peripheral autonomic neurons is positively matched with the size of the target they innervate, apparently by trophic interactions with the target (D. Purves, W. D. Snider, and J. T. Voyvodic. Nature Lond. 336: 123-128, 1988). We have asked whether the vascular hypertrophy associated with hypertension is accompanied by dendritic hypertrophy of sympathetic ganglion cells. To do this, we examined the morphology of stellate ganglion cells in the spontaneously hypertensive rat (SHR), its normotensive control Wistar-Kyoto rat (WKY), and two new strains derived from the SHR that independently express the hypertensive phenotype of the SHR (WKHT) and the behavioral hyperactivity present in the SHR (WKHA). Cells were examined by intracellular staining with horseradish peroxidase in in vitro preparations of the ganglia. Carotid arterial wall size was also examined. Significant hypertrophy of both the carotid arterial wall and stellate ganglion cell dendrites was observed in the two hypertensive strains (SHR and WKHT) but not in either of the normotensive strains (WKY and WKHA). This increased total dendritic length of stellate ganglion cells associated with hypertension provides a greater target area for preganglionic innervation that may result in hyperinnervation of these cells.
 ...
PMID:Hypertrophy of stellate ganglion cells in hypertensive, but not hyperactive, rats. 192 45

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.
 ...
PMID:Cerebrovascular permeability in acute hypertension: effect of flunarizine. 208 34

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)
 ...
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.
 ...
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.
 ...
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)
 ...
PMID:Microcirculation of the area postrema. Permeability and vascular responses. 275 49


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>