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)

The purpose of this study was to test the effects of a low-fat, low-cholesterol diet on serum lipids, platelet aggregation, thromboxane formation and blood pressure. Fifteen hyperlipidemic males with normal blood pressure were treated for 2 weeks. Resting supine blood pressure, total serum cholesterol, HDL-cholesterol, the ratio of total cholesterol/HDL-cholesterol and triglycerides all were significantly reduced. The maximum aggregation and velocity of aggregation for isolated platelets stimulated with either ADP or collagen was significantly reduced. Thromboxane formation during 5 min of platelet aggregation with collagen or ADP was also significantly reduced. These results have important implications for hypertension and atherosclerotic cardiovascular disease.
 ...
PMID:Effects of a low-fat, low-cholesterol diet on serum lipids, platelet aggregation and thromboxane formation. 347 54

We studied endothelium-dependent responses to substances released from aggregating platelets in spontaneously hypertensive rats (SHR) and normotensive Wistar-Kyoto rats (WKY). Rings of thoracic aorta with and without endothelium were taken from adult rats and suspended for isometric tension recording in organ chambers containing modified Krebs-Ringer bicarbonate solution. Aggregating platelets caused statistically similar contractions in rings without endothelium in both strains. In rings with endothelium from SHR the contractions were significantly more pronounced than in rings with endothelium from WKY. In contracted rings with endothelium, serotonin caused a slight relaxation at lower concentrations but contraction at higher concentrations; only contractions were seen in rings without endothelium. The higher concentrations of the monoamine caused contractions, which in the SHR but not in the WKY were larger in the presence than in the absence of endothelium. In both strains adenosine diphosphate induced concentration-dependent relaxation in rings with endothelium but not in those without it; at high concentrations of adenosine diphosphate, the relaxation responses were significantly smaller in the SHR than in the WKY. Endothelium-dependent relaxation in response to thrombin did not differ in the two strains. The increased contraction in response to aggregating platelets and serotonin and the decreased relaxation in response to adenosine diphosphate in the SHR suggest that functional changes occur in the endothelium in this model of hypertension, possibly because of the release of one or more endothelium-derived contracting factors.
Hypertension 1986 Jun
PMID:Endothelium-dependent responses to platelets and serotonin in spontaneously hypertensive rats. 348 6

The effects of diltiazem hydrochloride on exercise-induced changes in cardiovascular response, plasma renin activity, platelet function and blood coagulability were evaluated with multistage treadmill exercise in 20 patients who had systemic hypertension of stage 1 to 2 (World Health Organization classification). Heart rates, blood pressure, and pressure-rate product at rest, at peak exercise and in the recovery period were significantly reduced after 4 weeks of diltiazem administration, 180 mg/day. Plasma renin activity tended to increase after the medication. However, platelet adenosine diphosphate-induced aggregation sensitivity, prothrombin time, activated partial thromboplastin time, plasma fibrinogen concentration and antithrombin III activity did not change significantly. It is concluded that diltiazem could ameliorate the hyperresponsiveness of heart rate and BP to exercise in hypertensive patients without affecting blood coagulability.
 ...
PMID:Effects of diltiazem hydrochloride on cardiovascular response, platelet aggregation and coagulating activity during exercise testing in systemic hypertension. 351 20

Blood platelets of patients with essential hypertension display signs of both increased sensitivity in vitro to aggregating stimuli believed to contribute to thrombosis and of activation in vivo possibly expressing the release of vasoactive products. The mean features of the modified platelet profile in hypertension include an increased alpha 2-adrenergic receptor density, an enhanced rate of adhesion/aggregation in particular in response to ADP and arachidonic acid, a greater sensitivity for thrombin and adrenaline to stimulate increases in cytoplasmic-free Ca2+, increased resting levels of cytoplasmatic-free Ca2+, a reduced content of serotonin often combined with a defective uptake mechanism, a facilitated efflux rate of noradrenaline, an exaggerated release reaction in vivo as indicated by the increased plasma levels of Beta-thromboglobulin and a shortened platelet life span. These changes occur to various extents in some, but not all, hypertensive patients and are not always strictly related to the degree of blood pressure increase. On the contrary, platelet cyclooxygenase and thromboxane synthetase activity are in the normal range.
 ...
PMID:Blood platelets in human essential hypertension. 353 21

A study was carried out in 16 patients with moderately severe hypertension to investigate the effects of nifedipine, given alone or combined with a diuretic, on blood pressure and on renal and platelet function. After 4 weeks on placebo, patients were randomized to receive treatment for 6 weeks with either 20 mg, nifedipine twice daily or 25 mg mefruside once daily on a double-blind, double-dummy basis. All patients then received treatment for a further 6 weeks with a combination of the two drugs in the same dosage as before. The results of blood pressure measurements and laboratory investigations during the three phases of the study showed that significantly better blood pressure control was achieved with nifedipine alone than with mefruside alone. Mefruside had an additional hypotensive effect when added to nifedipine. There was no significant change in the renal blood flow or glomerular filtration rate, with a satisfactory control of blood pressure. There was also no detectable change in platelet aggregation with increasing concentrations of ADP and ristocetin. An adaptive mechanism could be responsible for the apparent lack of change compared with single dose studies.
 ...
PMID:Effect of nifedipine and mefruside on renal function and platelet function in hypertensive patients. 362 89

Stroke-prone spontaneously hypertensive rats (SHRSP) were treated with food admixed, 6,7-dimethoxy-1-(3,4-dimethoxybenzyl)-4-([4-(2-methoxyphenyl)-1- piperazinyl]methyl)isoquinoline (Ro 22-4839), a novel cerebral circulation improver, for a period of 15 weeks starting from 5 weeks of age at an average daily dose of 30.6 or 66.0 mg/kg. As compared with normotensive Wistar Kyoto rats, SHRSP in the control group rapidly developed severe hypertension (244 mmHg at the end of the experiments) accompanied with deterioration of cardiovascular parameters including left ventricular hypertrophy, reduction in pumping ability and increase in peripheral vascular tone. At 20 weeks of age (i.e. at the end of experiments), 75% of SHRSP developed stroke signs and concomitant cerebral edema evidenced by the increases in water and sodium contents in the brain. These stroke symptoms were accompanied with a profound externalized shape change of erythrocytes after in vitro treatment with Ca2+ and ionophore A23187, an increased plasma level of thiobarbituric acid reacting substance (TBARS), a measure of lipid peroxides, and a decreased sensitivity of platelets to ADP. The long-term treatment with Ro 22-4839 prevented the progress of stroke and cerebral edema, although the deteriorated cardiovascular parameters were not prevented by the treatment. This compound was also found to prevent the hypersusceptibility of erythrocyte membrane to Ca2+-ionophore and Ca2+, the hypoaggregability of platelets and the elevated plasma TBARS in SHRSP. These results indicate that the beneficial effects of Ro 22-4839 in SHRSP may be attributable to its calmodulin antagonistic and anti-lipid peroxidative actions but not to its hypotensive action.
 ...
PMID:Preventive effects of the cerebral circulation improver 6,7-dimethoxy-1-(3,4-dimethoxybenzyl)-4-([4-(2-methoxyphenyl)- 1-piperazinyl]methyl)isoquinoline on stroke symptoms in stroke-prone spontaneously hypertensive rats. 367 71

To test the hypothesis that an abnormality of the intracellular concentration of ionized calcium, [Ca2+]i, is associated with high blood pressure, we measured [Ca2+]i in the platelets of spontaneously hypertensive (SHR) and Wistar-Kyoto control (WKY) rats using the Quin 2 technique after separation of the platelets in calcium-free medium, during calcium repletion, and upon exposure to agonists which increase platelet [Ca2+]i (thrombin, adenosine diphosphate, serotonin and ionomycin). Despite clear-cut changes in [Ca2+]i during these manipulations, there were no differences between the SHR and WKY rats in baseline levels of [Ca2+]i or in the kinetics of changes in [Ca2+]i. These results do not support the hypothesis that high levels of [Ca2+]i at rest or abnormal kinetics of changes in [Ca2+]i play a pathophysiological role in the hypertension of SHR.
 ...
PMID:Cytosolic calcium in platelets of spontaneously hypertensive rats. 373 44

Forty-six elderly patients (mean age 60 years) suffering from diabetes mellitus (DM), or essential or arteriosclerotic hypertension (HT) were divided into 4 groups. Group 1 served as a control, group 2 was administered 1500 mg niceritrol, group 3 was administered 162 mg acetylsalicylic acid (ASA), and group 4 was administered both 1500 mg niceritrol and 162 mg ASA/day for 8 weeks. Niceritrol lowered serum levels of beta-lipoprotein and total cholesterol and increased HDL cholesterol, usually in 8 weeks. ASA did not affect the lipid-lowering effects of niceritrol. Platelet aggregation induced by epinephrine (1 microgram/ml), collagen (1 microgram/ml), and ADP (2 microM) was depressed in groups 2, 3 and 4. Degrees of depression were higher in groups administered ASA (groups 3 and 4) than in the group administered niceritrol alone (group 2). Plasma fibrinogen levels were lowered in groups administered niceritrol (groups 2 and 4) in 8 weeks. Apparent whole blood viscosity measured at shear rates of 37.6/s and 376/s was improved only in group 4 in 8 weeks, while hematocrit did not change during the study. Because flushing, the most frequent side effect of niceritrol, can be easily controlled by a low dose of ASA, and because the combination of the 2 drugs has some beneficial effects on blood rheology, this combination is considered worthwhile for treatment and prevention of atherosclerosis.
 ...
PMID:The effects on lipids, blood viscosity and platelet aggregation of combined use of niceritrol (Perycit) and a low dose of acetylsalicylic acid. 400 83

Effects of CV-2619 (10 and 30 mg/kg/day, p.o.) or ubiquinone-10 (Q-10, 10 mg/kg/day, p.o.) treatment for 5 weeks on systolic blood pressure (SBP) and myocardial energy metabolism were studied in spontaneously hypertensive rats of 20 weeks of age. The systolic blood pressure was about 205 mmHg at the start of the experiment, and a slight increase was noted thereafter in the control (vehicle) group. CV-2619, but not Q-10, inhibited the increase in the blood pressure. At 25 weeks of age, cardiac hypertrophy was noted to the same extent in either treated group. Myocardial contents of glycolytic intermediates (glycogen, glucose, pyruvate and lactate) and creatine phosphate (Cr-P), ATP, ADP, and AMP were not significantly influenced by CV-2619 or Q-10 treatment. CV-2619, however, significantly increased the energy charge, an index of myocardial energy state, with higher dose and lowered the lactate/pyruvate ratio with either dose. These results suggest that CV-2619 has a mild antihypertensive effect and improves the myocardial energy state in the hypertrophied heart during the sustained phase of hypertension in SHR rats.
 ...
PMID:[Effects of 2,3-dimethoxy-5-methyl-6-(10'-hydroxydecyl)-1,4-benzoquinone (CV-2619) on myocardial energy metabolism in the hypertrophied heart of spontaneously hypertensive rats]. 629 97

Prostacyclin (PGI2) was administered by inhalation (50 micrograms/min) and intravenous infusion (15 ng/kg/min) in 5 healthy male volunteers. Irrespective of the route of administration this substance was shown to have no effects on respiratory indices studied, whereas a significant inhibition of ADP-induced platelet aggregation and a fall in vascular resistance could be demonstrated. Mainly because of the latter action it is suggested that PGI2, or a stable synthetic analogue, might become a potent drug in various pathological conditions, in which hypertension of various causes is a problem.
 ...
PMID:Pulmonary and antiaggregatory effects of prostacyclin after inhalation and intravenous infusion. 638 93


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