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)

To determine whether inhibition of generation of endothelium-derived relaxing factor or nitric oxide (NO) resulted in elevated blood pressure and its effect on resistance arteries, rats were offered NG-nitro-L-arginine methyl ester (L-NAME), a competitive inhibitor of NO synthase, in their drinking water. Blood pressure (BP) rose slightly from 100 +/- 2 mmHg in controls to 130 +/- 5 mmHg with 25 mg/Kg L-NAME per day and to 173 +/- 9 mmHg with 100 mg/Kg per day for 2 1/2 to 4 weeks. Rats were studied after 1-2 weeks of hypertension (BP > 150 mmHg). The concentration of cyclic guanosine monophosphate, the intracellular second messenger of NO, was significantly depressed in aorta and in the mesenteric vascular bed in L-NAME-treated rats. Mesenteric resistance arteries studied on a wire-myograph exhibited similar external and lumen diameters, whereas media width and media/lumen ratio were greater (p < 0.01). Cross-sectional area of the media was similar. Active wall tension in response to norepinephrine tended to be greater in blood vessels from L-NAME-treated rats, while responses to vasopressin and endothelin-1 were unaltered. Sensitivity to norepinephrine was significantly enhanced in L-NAME-treated rats (p < 0.001), while that to endothelin-1 and arginine8 vasopressin was similar. In conclusion, administration of an NO synthase inhibitor produces hypertension, with exaggerated media/lumen ratio in resistance arteries and enhancement of response to norepinephrine, which together with decreased NO generation may contribute to elevation of blood pressure.
 ...
PMID:Effect of hypertension induced by nitric oxide synthase inhibition on structure and function of resistance arteries in the rat. 768 50

From Oct. 1990 to June 1991, alpha-granule membrane protein (GMP 140) were measured by MoAb radioimmunoassay in normal non-pregnant women (n = 24), normal late pregnancy (n = 26), late pregnancy with pregnancy-induced hypertension (PIH) (n = 27), and oral contraceptive users (n = 23). The results showed that (1) platelet GMP 140 of late pregnant women were significantly higher than that in nonpregnant controls; (2) There was no difference in GMP 140 between late pregnant group and PIH group; (3) Differences were not found among mild, moderate and severe PIH subgroups; (4) Platelet GMP140 was remarkably higher in oral contraceptive users than that in normal controls.
 ...
PMID:[Determination of platelet alpha-granule membrane protein in late pregnancy and oral contraceptive users]. 768 74

We examined the regulatory influence of nitric oxide on development of calcium- and protein kinase C-dependent basal tone in rings of thoracic aortas from rats with aortic coarctation-induced hypertension and from normotensive controls. Aortic rings from hypertensive rats but not those from normotensive rats, bathed in Krebs' bicarbonate buffer and subjected to 2 g of passive stretch, were relaxed by removal of calcium from the buffer and by the protein kinase C inhibitors staurosporine and calphostin C. Protein kinase C activity was much greater in homogenates of aortae from hypertensive rats than in those from normotensive controls (2124 +/- 785 versus 608 +/- 73 pmol.min-1.mg protein-1, respectively). Relaxant responses to removal of calcium and to staurosporine were greater in aortic rings rubbed to remove the vascular endothelium than in endothelium-intact rings (-1.07 +/- 0.12 versus -0.70 +/- 0.10 g tension/mg tissue, respectively, for calcium removal and -1.10 +/- 0.12 versus -0.65 +/- 0.08 g tension/mg tissue, respectively, for staurosporine). Treatment with an inhibitor of nitric oxide synthesis increased calcium-dependent tone in both intact and endothelium-denuded aortic rings from hypertensive rats. Conversely, the administration of sodium nitroprusside or L-arginine reversed tone in both intact and denuded aortic rings from hypertensive rats, but acetylcholine reversed tone only in intact rings. The relaxant effects of these agents were paralleled by increases in cyclic guanosine monophosphate in aortic tissue. We conclude that aortic rings from rats with aortic coarctation-induced hypertension display calcium-dependent, protein kinase C-mediated tone in the absence of exogenous vasoconstrictors.(ABSTRACT TRUNCATED AT 250 WORDS)
Hypertension 1995 Apr
PMID:Calcium- and protein kinase C-dependent basal tone in the aorta of hypertensive rats. 772 28

NG-nitro-L-arginine methyl ester (L-NAME) and 11-desoxycorticosterone plus salt intake (DOCA-salt) hypertensive rat models were compared to study the possible involvement of model-specific factors in the development of renal angiopathy and left ventricular hypertrophy (LVH). Blood pressure was measured in L-NAME, DOCA-salt hypertensive, and control Wistar rats, and the lesions of nephroangiosclerosis and left ventricular hypertrophy were evaluated after 7 weeks. Arterial wall cyclic guanosine monophosphate, plasma renin activity (PRA), and renal renin storage were assessed in parallel. For the same level of hypertension in the two models, the renal arterial fibrinoid necrotic lesions were significantly more frequent in L-NAME than in DOCA-salt hypertensive rats. In DOCA-salt hypertensive rats, PRA was decreased and arterial cGMP increased compared to controls. In the L-NAME model, arterial cGMP decreased and PRA showed a bimodal distribution in this intermediate stage of hypertensive disease. LVH was observed in DOCA-salt rats and only in the L-NAME rats with a high level of PRA. There was a close correlation between the lesions of nephroangiosclerosis, left ventricular index, and plasma renin activity in L-NAME rats. We therefore suggest that the activation of the renin-angiotensin system participates specifically in the development of the second stage of hypertension during chronic blockade of NO synthase involving nephroangiosclerosis and LVH.
 ...
PMID:Renal hypertensive angiopathy. Comparison between chronic NO suppression and DOCA-salt intoxication. 775 45

Atrial natriuretic peptide (ANP) specifically stimulates particulate guanylate cyclase, and cyclic guanosine monophosphate (cGMP) has been recognized as its second messenger. Spontaneously hypertensive rats (SHR) have elevated plasma ANP levels, but manifest an exaggerated natriuretic and diuretic response to exogenous ANP when compared to normotensive strains. In isolated glomeruli, the maximal cGMP response to ANP corresponds to a 12- to 14-fold increase over basal levels in normotensive strains (Wistar 13 +/- 2; Wistar-Kyoto 12 +/- 2; Sprague-Dawley 14 +/- 2) while a maximal 33 +/- 3-fold elevation occurs in SHR (P < 0.001). This hyperresponsiveness of cGMP is reproducible in intact glomeruli from SHR from various commercial sources. Furthermore, this abnormality develops early in life, even before hypertension is clearly established, and persists despite pharmacological modulation of blood pressure, indicating that it is a primary event in hypertension. In vitro studies have revealed a higher particulate guanylate cyclase activity in membranes from glomeruli and other tissues from SHR. This increase is not accounted for by different patterns of ANP binding to its receptor subtypes between normotensive and hypertensive strains, as assessed by competitive displacement with C-ANP102-121, an analog which selectively binds to one ANP receptor subtype. The hyperactivity of particulate guanylate cyclase in SHR and its behavior under basal, ligand (ANP), and detergent-enhanced conditions could be attributed either to increased expression or augmented sensitivity of the enzyme. Radiation-inactivation analysis does not evoke a disturbance in the size of regulatory elements normally repressing enzymatic activity, while the expression of particulate guanylate cyclase gene using mutated standard of A- and B-receptors partial cDNAs, quantified by polymerase chain reaction (PCR) transcript titration assay, manifests a selective increase of one guanylate cyclase subtype. Our data suggest that in hypertension, genetic overexpression of the ANP A-receptor subtype is related to the exaggerated biological response to ANP in this disease.
 ...
PMID:Increased cyclic guanosine monophosphate production and overexpression of atrial natriuretic peptide A-receptor mRNA in spontaneously hypertensive rats. 790 Dec 38

Two types of natriuretic peptide receptors (NPR-A and NPR-B) are membrane guanylate cyclases whose relative expression varies in different tissues. Because natriuretic peptides have been shown to inhibit aortic smooth muscle proliferation, we investigated the regulation of NPR-A and NPR-B in these cells under different proliferative conditions. NPR subtype mRNA levels were measured by our newly developed quantitative reverse transcription-polymerase chain reaction assay using mutated NPR-A and NPR-B cRNA as internal standards. The functional impact of their expression was determined by atrial natriuretic peptide (ANP)- and C-type natriuretic peptide (CNP)-induced stimulation of cyclic GMP production. In the intact aorta, NPR-B mRNA levels were found to be 10-fold higher than those of NPR-A. This dominance was further amplified (1000-fold) in long-term cultures (10 to 15 passages) of aortic smooth muscle cells (ASMC). Higher cyclic GMP production with CNP than with ANP was observed in cultured ASMC from Wistar-Kyoto (WKY) rats. Similar stimulation by the two agonists was noted in spontaneously hypertensive rat (SHR) cells, paralleled by a 10-fold increase in NPR-A mRNA levels and ANP stimulation of cyclic GMP in hypertensive cells. The present study also evaluated NPR-A and NPR-B mRNA control by transforming growth factor-beta 1 (TGF-beta 1), an important regulator of cell proliferation that is overexpressed in SHR ASMC. TGF-beta 1 decreased both NPR-A and NPR-B mRNA levels with a predominant effect in SHR cells at high cell density.(ABSTRACT TRUNCATED AT 250 WORDS)
Hypertension 1994 Jun
PMID:Regulation of natriuretic peptide receptor A and B expression by transforming growth factor-beta 1 in cultured aortic smooth muscle cells. 791 51

Urodilatin is a recently described member of the atrial natriuretic peptide family, thought possibly to be synthesized in the kidney. To determine if urodilatin binding sites are present in rat and human kidney, we evaluated the effect of urodilatin on iodine-125-labeled atrial natriuretic peptide (ANP) (100 pM) binding to tissue sections using an in situ autoradiographic technique. 125I-ANP binding occurred primarily in glomeruli and medullary structures of both rat and human kidney. Increasing concentrations of urodilatin yielded a monophasic displacement of 125I-ANP binding with an IC50 of 4.2 nM, a value nearly identical to that achieved with unlabeled ANP (7.2 nM). In additional experiments, rat glomeruli and inner medullary collecting duct cells were isolated and incubated in vitro with either ANP or urodilatin (10(-11) to 10(-6) M) and cyclic guanosine-3',5'-monophosphate accumulation measured by radioimmunoassay. Dose-response curves for the two peptides were superimposable in each tissue; at 10(-6) M, ANP generated 613 +/- 41 and urodilatin 603 +/- 55 fmol cyclic guanosine monophosphate per 10 minutes per milligram protein in inner medullary collecting duct cells (p = NS). Thus, urodilatin is as effective as ANP in displacing 125I-ANP binding to both rat and human renal tissue and in generating cyclic guanosine monophosphate in renal target cells in the rat, suggesting that its physiological effects may occur through the same receptors and signaling pathways that mediate the actions of ANP.
Hypertension 1993 Apr
PMID:Urodilatin binds to and activates renal receptors for atrial natriuretic peptide. 838

A nonhypotensive dose of atrial natriuretic peptide (ANP) was infused (60 pg/kg body wt per day s.c. by osmotic pump) for 25 days in 16-week-old normotensive Wistar-Kyoto rats (WKYs, n = 12) and age-matched spontaneously hypertensive rats (SHRs, n = 12). During the infusion period, systolic blood pressure, urinary volume, and cyclic guanosine monophosphate (cGMP) excretion/12 hr were measured once a week in both groups. Then mechanical and morphological properties of the arterial wall and plasma ANP levels were assessed and compared with those from control groups of SHRs (n = 8) and WKYs (n = 8) receiving a saline vehicle. The compliance (CC) of the in situ localized carotid artery was measured for pressures ranging from 25 to 175 mm Hg under control conditions and after "poisoning" of smooth muscle tone by potassium cyanide. After pressure fixation, the medial thickness, elastin and collagen contents, and the size and number of nuclei were measured in the thoracic descending aorta. In WKYs, ANP did not modify either mechanical or structural properties of the arterial wall or biochemical parameters. Conversely, in ANP-treated SHRs, CC was significantly increased compared with untreated SHRs under basal conditions (p < 0.03) and after potassium cyanide poisoning (p < 0.02). Structural properties were also modified by ANP in SHRs, i.e., medial thickness (129.3 +/- 4.1 versus 113.1 +/- 3.3 microns, p < 0.01) and nuclear size (8.81 +/- 0.28 versus 5.52 +/- 0.20 microns 2, p < 0.0001) in untreated and treated SHRs, respectively. Furthermore, urinary volume and cGMP content were significantly increased during ANP infusion in treated SHRs (p < 0.05). The present results indicate concomitant modifications of mechanical and structural properties of the arterial wall in SHRs chronically treated with low doses of ANP. These long-term effects of ANP could be involved in the remodeling of the arterial wall observed during hypertension and could have beneficial effects on cardiovascular diseases in chronic sustained hypertension.
 ...
PMID:Effect of a nonhypotensive long-term infusion of ANP on the mechanical and structural properties of the arterial wall in Wistar-Kyoto and spontaneously hypertensive rats. 838 30

The aim of the study was an evaluation of the effect of different dietary sodium intake on: blood pressure, plasma concentration of atrial natriuretic peptide (ANP), cyclic guanosine monophosphate (cGMP), aldosterone (ALDO) and plasma renin activity (PRA) in patients with primary sodium sensitive arterial hypertension class I acc. to WHO criteria. Thirteen patients, non treated, with sodium sensitive arterial hypertension aged 30 +/- 8 years participated in the study. Blood samples were taken three times: in 5th day of normal sodium intake (100-120 mmol Na per 24 h); in 5th day of low sodium diet (10-20 mmol Na per 24 h); in 5th day of high sodium diet (200-220 mmol Na per 24 h). During 24 hours before each blood sampling the urine was collected and sodium and potassium excretions were evaluated. Concentrations of ANP, cGMP, ALDO in plasma and PRA were determined by radioimmunoassays and serum sodium and potassium concentration by flame photometry. Significant (p < 0.05) diminution of blood pressure, plasma ANP and cGMP concentrations and the increase of plasma ALDO and PRA after sodium restriction when compared to normal sodium diet were found. High sodium diet resulted in significant increase of blood pressure, plasma ANP and cGMP concentrations to the values comparable with these on normal sodium diet. On the contrary PRA and plasma ALDO concentration decreased (p < 0.001) below the values during normal sodium diet. Urinary sodium excretion corresponded to dietary sodium intake during all diets.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:[Effect of different amounts of dietary sodium on plasma atrial natriuretic peptide (ANP)in essential salt sensitive hypertension]. 838 44

The aim of this work was an evaluation of the effect of the acute hypervolemia induced by 90 min intravenous infusion of 1500 ml 0.9% NaCl (16.7 ml/min) on blood pressure, plasma concentration of the atrial natriuretic peptide (ANP), cyclic guanosine monophosphate (cGMP), aldosterone (ALDO), plasma renin activity (PRA) in patients with essential hypertension on the normal, low and high sodium intake. Twelve patients with noncomplicated essential sodium-sensitive arterial hypertension participated in the study. Sodium chloride infusions were performed three times: first--on the fifth day of normal daily sodium u intake (110-120 mmol/day), second--on the fifth day of low sodium intake (10-20 mmol/day), third--on the fifth day of high sodium intake (200-220 mmol/day). Acute intravenous sodium chloride load induced a significant increase of the mean arterial pressure (MBP) only when the patients were on the high sodium diet. This increase of the MBP was associated with a significantly lower increment of plasma ANP, cGMP, lower decrement of ALDO and PRA when compared to normal- or low- sodium intake. The results suggest an impairment of the adaptive homeostatic mechanisms induced by an acute intravenous sodium load in patients with noncomplicated salt-sensitive essential hypertension ingesting high-sodium diet.
 ...
PMID:[Effect of intravenous sodium chloride load on levels of atrial natriuretic peptide (ANP) and 3'5' guanosine monophosphate (cGMP) in plasma of patients with uncomplicated sodium-sensitive arterial hypertension maintained on different dietary sodium intake]. 838 45


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