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)

Nephrogenic adenofibroma is a novel kidney tumor of young people (mean age of presentation, 13 years), who present with polycythemia, hypertension, or hematuria, which resolve following nephrectomy. The typical nephrectomy specimen contains a solitary, nonencapsulated, vaguely circumscribed, irregularly shaped or spherical, firm mass with either tan, gray-white, or pale yellow coloration. Cysts are sometimes present within the tumor. The histologic appearance is distinctive and characterized by a marked proliferation of spindled mesenchymal cells resembling the classical type of congenital mesoblastic nephroma, encasing discrete nodules of embryonal epithelium similar to the hyperplastic nephrogenic rests (nephroblastomatosis) usually associated with Wilms' tumor. The mesenchymal component consists of a fascicular proliferation of tightly interlaced, uniform, benign-appearing spindled cells that immunostatin for vimentin and fibronectin, but not desmin or actin. The epithelial component consists of discrete islands of blastemal cells that are partially or fully differentiated toward tubular, tubulopapillary, or papillary structures. Psammoma bodies are plentiful. Embryonal epithelium immunostains for cytokeratin but not epithelial membrane antigen. The overall histologic appearance of the mesenchymal and epithelial components is benign, and preliminary clinical data suggest that the tumor has a benevolent course. Two cases, however, contained small, well-circumscribed papillary lesions near the renal pelvis that resembled low-grade collecting duct carcinoma. The clinical implications of the latter finding are unclear.
 ...
PMID:Nephrogenic adenofibroma. A novel kidney tumor of young people. 137 78

To define the interplay of glomerular hypertension and hypertrophy with mesangial extracellular matrix (ECM) deposition, we examined the effects of glomerular capillary distention and mesangial cell stretching on ECM synthesis. The volume of microdissected rat glomeruli (Vg), perfused ex vivo at increasing flows, was quantified and related to the proximal intraglomerular pressure (PIP). Glomerular compliance, expressed as the slope of the positive linear relationship between PIP and Vg was 7.68 x 10(3) microns 3/mmHg. Total Vg increment (PIP 0-150 mmHg) was 1.162 x 10(6) microns 3 or 61% (n = 13). A 16% increase in Vg was obtained over the PIP range equivalent to the pathophysiological limits of mean transcapillary pressure difference. A similar effect of renal perfusion on Vg was also noted histologically in tissue from kidneys perfused/fixed in vivo. Cultured mesangial cells undergoing cyclic stretching increased their synthesis of protein, total collagen, and key components of ECM (collagen IV, collagen I, laminin, fibronectin). Synthetic rates were stimulated by cell growth and the degree of stretching. These results suggest that capillary expansion and stretching of mesangial cells by glomerular hypertension provokes increased ECM production which is accentuated by cell growth and glomerular hypertrophy. Mesangial expansion and glomerulosclerosis might result from this interplay of mechanical and metabolic forces.
 ...
PMID:Intraglomerular pressure and mesangial stretching stimulate extracellular matrix formation in the rat. 143 Feb 16

Chronic increases in haemodynamic load modify the expression of cardiac genes, leading to cardiac hypertrophy and a new phenotype. As an example, changes in the expression of the genes encoding the main contractile proteins, the isomyosin heavy chains, have been associated with modifications of the physiological properties of cardiac muscle. The cellular and molecular mechanisms which either do or do not initiate and maintain these changes in cardiac genomic expression remain to be elucidated. Using in situ hybridization we show that mRNAs encoding a cellular form of fibronectin (c-FN), a protein of the basal membrane which is not or poorly expressed in adult rat heart, are reexpressed as a result of severe hypertension with a similar time course than the beta-heavy chain of myosin (beta-MHC), also mostly expressed in fetal heart. The accumulation of the c-FN mRNAs was found in the wall of coronary arteries whilst that of the beta-MHC mRNAs occurred in the myocytes at the border zone of these arteries. Thus a high pressure in the arteries could be the trigger inducing the synthesis of factors which could, through a gradient, modulate the phenotype of both the smooth muscle cells of the media and the cardiocytes. Besides, using a model of cultured adult rat cardiocytes, we show that the differential expression of the MHC isoforms is dependent on the beta-adrenergic stimulation but that the regulation depends on the stage of development of the cells and differs for the alpha and beta MHC. These 2 complementary approaches for identifying the molecular mechanisms that control cardiac muscle growth should help for understanding cardiac adaptation triggered by haemodynamic overload, such as arterial hypertension as well as cardiac failure.
 ...
PMID:[Changes in heart genome expression in hypertensive diseases]. 149 74

The accumulation of extracellular matrix (ECM) is an important feature of most forms of progressive glomerular diseases. In order to examine the relationship between ECM synthesis and glomerulosclerosis, we evaluated fibronectin synthesis by glomeruli with the immunoprecipitation of conditioned media from isolated glomeruli in 5/6 nephrectomized spontaneously hypertensive rats (5/6N-SHR). There was no difference in blood pressure between 5/6N-SHR and control SHR throughout the experiment. Two weeks after the nephrectomy, most of the glomeruli were intact and no difference in the synthesis of fibronectin was observed between either groups. Twenty weeks after the nephrectomy, marked glomerulosclerosis associated with an increase in urinary protein was revealed in 5/6N-SHR but no glomerular lesions in control SHR. The synthesis of fibronectin by isolated glomeruli increased in 5/6N-SHR compared to control SHR. The administration of enalapril or hydralazine + reserpine + hydrochlorothiazide markedly attenuated the glomerular sclerosis and urinary protein excretion to a comparable degree, although the later therapy reduced blood pressure more effectively. These antihypertensive therapies also suppressed fibronectin synthesis in the 5/6N-SHR group at week 20. In conclusion, increased synthesis of glomerular fibronectin appeared to contribute to the glomerulosclerosis caused by subtotal nephrectomy and hypertension.
 ...
PMID:Synthesis of fibronectin by isolated glomeruli from nephrectomized hypertensive rats. 150 45

We examined changes in the expression of fibronectin during the induction of cardiac hypertrophy by L-triiodothyronine administration and by mineralocorticoid- and salt-induced experimental hypertension. By use of Northern and Western blotting procedures, fibronectin was localized mainly in the atria of normal rat hearts. Atria contained 10- and 5-fold higher relative concentrations of fibronectin mRNA and protein, respectively, compared with ventricles. During the progression of cardiac hypertrophy induced by L-triiodothyronine over a 10-d period, there was a progressive increase in fibronectin mRNA for the first 6 d followed by a return to control levels. The major change could be accounted for by changes in ventricular mRNA, which increased about four- to sixfold. In contrast, protein levels in ventricles increased progressively over the 10-d treatment period. Ribonuclease protection analysis indicated that the relative amounts of fibronectin isoforms containing exons designated EIIIA and EIIIB increased during the progression of hypertrophy. When cardiac hypertrophy was induced by mineralocorticoid and salt treatment, increases in ventricular fibronectin mRNA and protein and the induction of alternatively spliced forms of fibronectin were also observed. However, the extent and temporal pattern of fibronectin expression differed between the two experimental models.
 ...
PMID:Fibronectin expression in the normal and hypertrophic rat heart. 153 44

Increased plasma fibronectin levels are a highly sensitive and specific predictor of gestational hypertension. Of a total of 105 apparently healthy normotensive primigravid women seen at the outpatient clinic, 10 with increased plasma levels of fibronectin (mean +/- 2 SD), were compared with 14 controls. Parameters of early vascular damage (laminin, preprocollagen III), platelet activation (beta-thromboglobulin, platelet factor 4), and coagulation (thrombin-antithrombin III complexes, fibrinopeptide A) were measured at regular (weekly or monthly) intervals. Abnormal values of laminin (p less than 0.005) and fibronectin (p less than 0.0001) were found up to 4 weeks before the onset of clinical disease. Levels of beta-thromboglobulin (p less than 0.0001) were also elevated at least 4 weeks before the appearance of clinical symptoms. Our results show that increased levels of laminin, fibronectin, and platelet activation, as indicated by beta-thromboglobulin levels, are preclinical features of gestational hypertension and indicate that vascular damage has occurred. Fibrin formation would appear to occur later.
 ...
PMID:Platelet activation and vascular damage in gestational hypertension. 153 75

Fibronectin expression was shown recently to increase in the rat aorta in response to experimental hypertension. Fibronectin is known to alter the phenotype of vascular smooth muscle and endothelial cells, and relative changes in the expression of different isoforms of fibronectin, generated by alternative splicing and distinguished by the absence or presence of inserts designated as EIIIA, EIIIB, and V, may reflect a change in cell phenotype. In the present study we examined the expression of alternatively spliced forms of aortic fibronectin during deoxycorticosterone-salt hypertension. Aortic RNA was analyzed quantitatively using Northern blot analysis and ribonuclease protection assays. Using Northern blot analysis, deoxycorticosterone-salt treatment for 21 days led to a 4.9-fold increase in EIIIA fibronectin messenger RNA, while EIIIB and V forms increased by 2.6- and 2.5-fold, respectively. As determined by ribonuclease protection assays, the percentage of fibronectin transcripts containing either EIIIA, EIIIB, or V in control aorta was 7.3%, 19%, and 40%, respectively. The percentage of EIIIA transcripts increased 42% over control levels after 21 days of deoxycorticosterone-salt treatment, whereas no proportionate change in the other alternatively spliced forms was found. Thus, all forms increased, but a selective increase in the EIIIA form was induced. Analogous increases in each of the fibronectin isoforms were found in the spontaneously hypertensive rats when compared with age-matched Wistar-Kyoto or Wistar rats, and 40-week-old animals showed increases over 10-week-old animals in all strains, consistent with an age-dependent increase in aortic fibronectin expression.
Hypertension 1992 Jul
PMID:Hypertension induces alternatively spliced forms of fibronectin in rat aorta. 161 48

A prospective randomized double-blind study was carried out in pregnant women with risk of pregnancy induced hypertension (PIH). Low dose Aspirin (50 mg/day) or placebo was given consecutively from the 28th weeks of gestation. The results have shown that 8% of the pregnant women in the aspirin treatment group had developed PIH, which was substantially lower than that in the control group (24%) (P less than 0.05). The ratio of TXB2/6-keto-PGF1 alpha increased significantly in the control group while it remained unchanged in treatment group. Increasing plasma fibronectin (Fn) and decreasing AT-III level were seen in the control group but no changes of these parameters in the treatment group. It was presumed that low dose aspirin may have prophylactic effect on PIH. The mechanism of aspirin may be the inhibition of TXA2 and Fn synthesis and decreased consumption of AT-III.
 ...
PMID:[Low-dose aspirin preventing pregnancy induced hypertension]. 180 3

The aim of the present study was to investigate whether angiotensin II, by increasing extracellular matrix synthesis, contributed to the vascular wall thickening observed in hypertension. Thus, we examined the direct effects of angiotensin II on collagen and fibronectin synthesis in cultured rat vascular smooth muscle cells by measuring 3H-proline incorporation. Angiotensin II, in a concentration of 10 mumol/l, increased collagen synthesis in a dose-dependent manner up to 1.8-fold. This increase occurred within 24 h after the addition of angiotensin II and the time required to reach maximum stimulation was approximately 48 h. This increase was receptor-mediated and correlated with an increase in its specific messenger RNA. A closer study of the collagen increase demonstrated a relatively greater increase in type V collagen than type I or type III collagen. Fibronectin synthesis was also increased 1.5-fold with 10 mumol/l angiotensin II. These data suggest that angiotensin II induces vascular wall thickening by acting directly on smooth muscle cells and enhancing the production of extracellular matrix proteins.
 ...
PMID:Angiotensin II stimulates collagen synthesis in cultured vascular smooth muscle cells. 184 53

This study was undertaken to determine if changes in fibronectin biosynthesis accompany the phenotypic changes that occur in aortic tissue following experimental hypertension. An in vitro procedure was developed to measure fibronectin synthesis in aortic rings obtained from normotensive or hypertensive rats. There was a three to sixfold increase in fibronectin biosynthesis by aortic rings taken from rats treated with deoxycorticosterone/salt for 7 and 21 d, the change being more pronounced at 21 d. In contrast, there was no major change at either time point in net incorporation into total protein. Studies comparing fibronectin biosynthesis in aortic rings from Wistar rats and spontaneously hypertensive rats at ages between 10 and 40 wk showed increased fibronectin biosynthesis in older animals of both strains, but only slight differences between strains. Studies using rats infused with angiotensin II showed a correlation between blood pressure elevation and increased aortic fibronectin biosynthesis. Western blot analysis of aortic extracts showed that the fibronectin content was increased in the hypertensive models. The in vitro procedure for measuring fibronectin biosynthesis appears to provide a reliable reflection of in vivo changes in fibronectin expression, and the methodology could prove useful for studying the factors influencing protein expression in vascular tissue.
 ...
PMID:Fibronectin biosynthesis in the rat aorta in vitro. Changes due to experimental hypertension. 191 73


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