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)

1. To explore the effect of nephritis on development of genetic hypertension we immunized 10-week-old spontaneously hypertensive rats with purified rat kidney brush-border antigen. This induces Heymann nephritis (autologous immune complex nephritis), which does not elevate blood pressure in normal rats. 2. Nephritis developed in 11 of the 12 immunized animals, and systolic blood pressure rose to a significantly higher level than in the non-immunized spontaneously hypertensive rats within 4 weeks. Blood pressure remained higher in the immunized rats at 17 weeks, heart weights were greater, but creatinine clearance remained unchanged. 3. At 6 weeks, urinary sodium excretion was greater in the immunized spontaneously hypertensive rats, whereas at 17 weeks, sodium excretion was decreased in these animals along with reduced serum protein concentration, packed cell volume and plasma renin activity, as compared with that of the controls. 4. Development of hypertension in nephritic rats, therefore, appeared unrelated to sodium excretion; signs of volume expansion emerged later. 5. Acceleration of the development of spontaneous hypertension by Heymann nephritis, also leading to sustained higher blood pressure levels than in spontaneously hypertensive rats, offers a new approach to experimental study of immune mechanisms behind acceleration of pre-existing hypertension. This may have important bearings on essential hypertension as well.
 ...
PMID:Aggravation of hypertension in spontaneously hypertensive rats by Heymann nephritis. 723 40

In order to explore the impact of nephritis on the development of hypertension, rats with Heymann nephritis were given 0.9% NaCl to drink, in combination with or without DOCA injections, for up to 6 months. Combined nephritis-DOCA-NaCl resulted in severe hypertension and shortened life span, whereas nephritis-NaCl combination failed to induce hypertension or shorten life span. All immunized rats developed membranous glomerulonephritis but creatinine clearance did not decrease. DOCA-NaCl-treated nephritic rats had a heavier proteinuria and more marked renal lesions than NaCl-treated nephritis rats. Proliferative-sclerotic glomerular lesions were seen in the nephritis-DOCA-NaCl group only, correlating to the severity of hypertension. Other renal and extrarenal vascular lesions, increasing with time, also appeared related to the severity of hypertension. This suggests a secondary relationship of vascular damage to hypertension in this model. Appearance of proteinuria preceded the establishment of hypertension, suggesting that nephritis sensitized to the development of hypertension during DOCA-NaCl treatment. Sodium excess alone, however, did not induce hypertension in Heymann nephritic rats. The present Heymann nephritis-DOCA-NaCl hypertension model appears a useful model for the study of hypertension complicating glomerulonephritis.
 ...
PMID:Heymann nephritis-DOCA-NaCl hypertension in the rat. Role of nephritis, DOCA, NaCl, and vascular lesions in the development of hypertension. 729 Feb 77

In order to explore the effect of immunologically-induced nephropathy versus a non-immunological model on development of hypertension, rats with either Heymann nephritis or N,N'-diacetylbenzidine (N,N'-DAB)-induced nephropathy were subjected to DOCA-NaCl treatment. Hypertension developed during DOCA-NaCl treatment in Heymann nephritic rats but not in rats wih N, N'-DAB nephropathy, despite similar degrees of proteinuria and other features of nephrosis. There were no signs of different fluid balance, either. Azotemia did not ensue. Histology and immunohistology showed membranous glomerulonephritis in Heymann nephritic rats whereas glomerular epithelial cell alterations without immune deposits along the glomerular capillary walls were seen in rats with N, N'-DAB nephropathy. The type of renal damage or factors mediating such damage appear to be important determinants for the hypertensive response of Heymann nephritic rats to DOCA-NaCl treatment.
 ...
PMID:Different blood pressure response to DOCA-NaCl treatment in autoimmune and N,N'- diacetylbenzidine-induced nephropathies. 731 56

The receptor-associated protein (RAP) specifically associates with gp330 and the low density lipoprotein (LDL) receptor-related protein (LRP), the two newest members of the LDL receptor gene family. Results obtained by ligand blotting, affinity chromatography, and density-gradient sedimentation demonstrate that RAP binds to both receptors with high affinity and that the binding is Ca2+ dependent. RAP also binds heparin and is identical to a mouse heparin binding protein (HBP-44) identified in a teratocarcinoma cell line (F9). While biochemical studies have shown that RAP is present on the cell surface and is an effective inhibitor of ligand binding to gp330 and LRP, immunocytochemical findings indicate that RAP is most abundant in the endoplasmic reticulum lumen and may function in receptor folding and/or trafficking. To facilitate the characterization of RAP's function(s) we have mapped its gp330 and heparin binding sites by performing direct binding studies on fusion proteins representing overlapping domains of RAP. gp330 was found to bind to two separate sites on RAP--i.e., between amino acids 85-148 and 178-248. Binding studies with radiolabeled heparin indicate that the heparin binding site is between amino acids 261 and 323, which is consistent with our previously proposed site (residues 287-306) based on the amphipathic nature of the C terminus of RAP. These data demonstrate that the gp330 and heparin binding sites and the Heymann nephritis pathogenic epitope (amino acids 1-86) demonstrated earlier are represented by distinct domains of the RAP polypeptide.
 ...
PMID:Functional domains of the receptor-associated protein (RAP). 751 26

Heparin binding protein-44 (HBP-44) is a heparin binding protein of 44 kDa, found by cDNA cloning using antibodies against teratocarcinoma glycoproteins [Furukawa, T. et al. (1990) J. Biochem. 108, 297-302]. The N-terminal sequence analysis reported in this publication establishes the structure of its mature form. Immunohistochemical staining revealed that HBP-44 was located in the tubular brush border of the kidney. HBP-44 formed a complex with brushin, a high molecular weight (450 kDa) glycoprotein antigen common to the kidney and teratocarcinoma, but not with OR8 antigen, another antigen (350 kDa) of the same category. Brushin was shown to be the mouse counterpart of rat Heymann nephritis antigen, called gp330. The association between HBP-44 and brushin was revealed not only by co-precipitation upon indirect immunoprecipitation, but also by ligand blotting with HBP-44-maltose binding protein fusion protein. Calcium ion stabilized the association. Disulfide bonds in brushin seemed to be necessary for the complex formation, since reductive cleavage of the bonds resulted in failure of the protein to associate with HBP-44 in a ligand blotting experiment. Association of HBP-44 with brushin occurred both in teratocarcinoma cells, in which these molecules are mainly located in extraembryonic endoderm cells, and in the kidney, suggesting that the complex has an unknown common function in the renal tubular brush border and the extraembryonic endoderm.
 ...
PMID:Mouse heparin binding protein-44 (HBP-44) associates with brushin, a high-molecular-weight glycoprotein antigen common to the kidney and teratocarcinomas. 828 24

In these studies, the Fx1A model of accelerated, passive Heymann nephritis was used to produce membranous glomerulonephropathy. Female rats were studied at 7 wk after the administration of the Fx1A antibody either in the virgin state or in late pregnancy. The goals of these experiments were to determine whether preexisting membranous glomerulonephropathy compromises the pregnancy and whether the pregnancy acutely worsens the renal function. Virgin rats with membranous glomerulonephropathy developed massive proteinuria and exhibited glomerular capillary hypertension but without declines in GFR. In late pregnancy, there was no worsening of the proteinuria and glomerular blood pressure fell to normal values. Both afferent and efferent arteriolar resistances increased in pregnant rats with membranous glomerulonephropathy compared with virgins, leading to falls in glomerular plasma flow and single-nephron GFR. There were no histologic abnormalities in the glomeruli of either virgin or late pregnant rats with membranous glomerulonephropathy, and both groups exhibited similar immunoglobulin G and complement deposits. Up to Day 19 (term is 22 days), the pregnancy in rats with membranous glomerulonephropathy appeared uneventful. Thus, this study indicates that the Fx1A model of membranous glomerulonephropathy does not compromise the course of the pregnancy, at least until close to term. Pregnancy lowers glomerular blood pressure in rats with membranous glomerulonephropathy because of both a fall in systemic blood pressure and the atypical renal vasoconstriction, which leads to declines in single-nephron GFR.
 ...
PMID:Glomerular hemodynamic effects of late pregnancy in rats with experimental membranous glomerulonephropathy. 858 86

DOCA-NaCl treatment causes hypertension, accelerates development of proteinuria, and leads to glomerulosclerosis in rats with autoimmune Heymann nephritis. To study the mechanisms of kidney injury induced by renal haemodynamic load in chronic nephritis, we studied by immunohistochemistry the local expression of various cytokines, growth factors and adhesion molecules in the kidneys of Heymann nephritic rats with or without DOCA-NaCl-induced hypertension. The DOCA-NaCl-nephritis group developed hypertension and marked renal enlargement as compared with the nephritis group, the DOCA-NaCl group, and the controls. Albuminuria appeared earlier and was heavier in the DOCA-NaCl-nephritis group compared with the nephritic rats without DOCA-NaCl. Expression of IL-6, TNF-alpha, GM-CSF, b-FGF, NGF, TGF-beta, and ICAM-1 was enhanced in the kidneys of the DOCA-NaCl-nephritis group as compared with other groups, localized mainly in the glomerular mesangium (IL-6, GM-CSF, TGF-beta), glomerular and peritubular endothelium (ICAM-1), and collecting ducts (TNF-alpha, b-FGF, NGF, TGF-beta), possibly associated with the observed tubulointerstitial mononuclear cellular infiltration. Thus in autoimmune Heymann nephritis, DOCA-NaCl treatment causes hypertension and increased renal mass together with upregulation of local cytokine and growth factor production, which may further aggravate hypertension and accelerate progression of renal damage.
 ...
PMID:Increased renal expression of cytokines and growth factors induced by DOCA-NaCl treatment in Heymann nephritis. 880 10

Effects of nitric oxide (NO) synthase inhibition on blood pressure and on the course of Heymann nephritis was examined in rats. L-NG-nitroarginine-methylester (L-NAME, 10 mg/100 ml in the drinking water for 12 weeks) was used as an inhibitor of NO synthase. Urinary excretion of guanosine 3',5'-cyclic monophosphate (cGMP), a second messenger of NO, was used as an indirect estimate of NO activity. Rats were divided into the following groups: control, nephritis, L-NAME, and nephritis-L-NAME. Urinary cGMP excretion was lower in the nephritis group (p < 0.05) and in the nephritis-L-NAME group (p < 0.005) compared with controls. Plasma atrial natriuretic peptide (ANP) levels were elevated in the nephritis (p < 0.001) and in the nephritis-L-NAME groups (p < 0.05. L-NAME treatment alone did not have any effect on plasma ANP levels. Blood pressure rose progressively in all L-NAME-treated rats. Most marked albuminuria developed in the nephritis-L-NAME group. No differences in the immunohistological findings were observed between the nephritis and the nephritis-L-NAME groups. NO synthase inhibition causes hypertension and aggravates albuminuria in chronic nephritis. Moreover, nephritis itself may decrease then production of cGMP either as a consequence of blunted NO activity or, in addition, because of ANP resistance. It appears that NO synthase inhibition does not change the immunological course of Heymann nephritis but rather the increased hemodynamic load makes the course of nephritis worse.
 ...
PMID:Chronic inhibition of nitric oxide synthase in Heymann nephritis. 888 33

In several models of renal disease progression, angiotensin-converting enzyme (ACE) inhibitors reduced proteinuria and limited glomerulosclerosis, which suggested that reduction of renal angiotensin II (Ang II) activity is crucial for the preservation of glomerular structure and function. However, it cannot be ruled out that other hormonal systems, including inhibition of the bradykinin breakdown, also play a role. We compared the effects of chronic treatment with the ACE inhibitor lisinopril with those of a specific Ang II receptor antagonist, L-158,809, on proteinuria and renal injury in passive Heymann nephritis (PHN), a model of immune renal disease that closely resembles human membranous nephropathy, with long-lasting proteinuria followed by tubulointerstitial damage and glomerulosclerosis. Passive Heymann nephritis was induced with 0.5 mL/100 g of rabbit anti-Fx1A antibody in 24 male Sprague-Dawley rats. The animals were divided into three groups of eight rats each, and were given the following in the drinking water on a daily basis: lisinopril (40 mg/L), L-158,809 (50 mg/L), or no therapy. Treatment started at day 7 (proteinuria was already present) and lasted 12 months. Eight normal rats were used as controls. Untreated PHN rats developed hypertension, while rats with PHN given lisinopril or L-158,809 all had systolic blood pressure values even lower than those of normal rats. Urinary protein excretion progressively increased with time in untreated PHN rats, who developed tubulointerstitial damage and glomerulosclerosis. Both lisinopril and L-158,809 exhibited a potent antiproteinuric effect and preserved glomerular and tubular structural integrity at a similar extent. Renal gene expression of transforming growth factor-beta and extracellular matrix proteins was also effectively reduced by the two treatments. These results indicate that ACE inhibitors and Ang II receptor antagonists are equally effective in preventing renal injury in PHN and suggest that the renoprotective effects of ACE inhibitors in this model are solely due to inhibition of Ang II.
 ...
PMID:The renoprotective properties of angiotensin-converting enzyme inhibitors in a chronic model of membranous nephropathy are solely due to the inhibition of angiotensin II: evidence based on comparative studies with a receptor antagonist. 901 98

In proteinuric nephropathies tubular atrophy leads to glomerular-tubule disconnection through an unknown mechanism. Here we studied whether proteinuria promoted glomerular-tubule disconnection in individual nephrons and whether this phenomenon was prevented by an angiotensin-converting enzyme (ACE) inhibitor. Passive Heymann nephritis (PHN) and control rats were studied at 4 and 8 months. Two additional groups of PHN rats received lisinopril (40 mg/L) or a calcium channel blocker (lacidipine, 3 mg/kg) from day 7 after surgery to 8 months. At sacrifice, kidneys were serially sectioned to identify glomerular- tubule abnormalities in individual nephrons and changes in interstitial volume. In PHN rats, the time-dependent increase in proteinuria was paralleled by tubular atrophy leading to glomerular-tubule disconnection and interstitial volume enlargement. Marked apoptosis was invariably found in atrophic tubules in contrast to the absent or very mild terminal dUTP nick-end labeling staining in tubules normally connected to glomeruli in PHN animals. Treatment with an ACE inhibitor prevented hypertension, proteinuria, the formation of atrophic tubuli, glomerular-tubule disconnection and limited the fractional interstitial volume expansion. Although lacidipine limited hypertension, it did not reduce proteinuria or prevent tubular atrophy and disconnection. Multivariate analysis showed that the appearance of atubular glomeruli and the increase in interstitial volume were better predicted by proteinuria than blood pressure. This study suggests that ACE inhibitors effectively prevent glomerular-tubule disconnection possibly by their ability of reducing proteinuria, which in turn favors proximal tubular cell apoptosis. Agents that only reduced hypertension but not proteinuria do not affect tubular behavior.
 ...
PMID:Angiotensin-converting enzyme inhibition prevents glomerular-tubule disconnection and atrophy in passive Heymann nephritis, an effect not observed with a calcium antagonist. 1169 35


<< Previous 1 2