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

Hypertension was found in four patients after unilateral renal-artery thrombosis following blunt abdominal trauma. In one patient, who was followed up from the time of injury, renin hypersecretion and secondary aldosteronism developed within a few days, and hypertension was present 12 weeks later. Increasing haemoglobin and raised blood-erythropoietin concentrations were also found. In the three other patients, hypertension was found casually within 3 years of trauma. In all patients, unilateral renin production by the affected kidney was significantly increased. Nephrectomy of the diseased kidney corrected hypertension and endocrine abnormalities in all patients. The delayed onset of hypertension despite early activation of the renin/angiotensin/aldosterone axis accords with the course of events observed in experimentally induced hypertension in rats, and suggests that several weeks or even months are required for hypertension to develop after sudden renal-artery occlusion in man. Slowly acting mechanisms, probably initiated by hypersecretion of renin, may be responsible for the hypertension.
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PMID:Renin/angiotensin system in hypertension after traumatic renal-artery thrombosis. 5 38

The case is described of a patient on intermittent hemodialysis who had had a bilateral nephrectomy but had hypertension and a surprisingly mild degree of anemia. Repeated determinations showed high plasma renin activity and plasma erythropoietin activity within the detectable range. These results were thought to be related to a completely calcified renal allograft which had been inserted 8 years before and which had been rejected four years later, but left in situ. The patient had become anuric. It is suggested that chronically rejected renal allografts, even calcified, may maintain some endocrine activity in the absence of any excretory function.
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PMID:Possible persistent endocrine function of a rejected renal allograft. 34 85

The functioning canine renal allograft produces plasma renin activity (PRA) and erythropoietin (ESF) activity and can maintain normal blood pressure and normal erythropoiesis. Moreover, in response to various provocative stimuli it can: (i) increase plasma renin activity in response to low sodium intake; (ii) suppress PRA in response to high sodium intake; (iii) produce increased serum erythropoietin in response to hypoxia. The granulation activity of the juxtaglomerular apparatus correlates best with the degree of graft rejection and with the PRA in groups manipulated by changing sodium balance. This is not the case with hypoxia. Thus, the juxtaglomerular apparatus, even in the presence of vascular changes seen with the severe degree of rejection in renal allografts, can respond to stimuli that can regulate renin release. Renin production by the transplanted kidney can be dissociated from ESF secretion. Blood pressure changes in the present model were not directly associated with increased PRA or juxtaglomerular apparatus activity. In such conditions hypertension can exist in the presence of suppressed PRA and without hypergranulation of the apparatus. The majority of correlations of this study thus establish a close association of the degree of juxtaglomerular index activity with PRA levels, rather than ESF.
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PMID:The response of the juxtaglomerular apparatus to stimuli effecting renin or erythropoietin release in canine renal allografts. 76 86

Serum concentration of erythropoietin (EP) was measured with a hemagglutination inhibition technique and plasma renin activity (PRA) with a radioimmunoassay for angiotensin I in 26 renal transplant recipients 2-54 months after renal transplantation. In all patients, the EP values were significantly correlated with the levels of PRA (r = 0.76 p less than 0.001) and hematocrit values (r = 0.72, p less than 0.001). In one patient, erythrocytosis and high blood pressure associated with high EP and PRA levels disappeared after bilateral nephrectomy of his own kidneys. The results indicate an as yet unidentified relationship between the production of EP and renin.
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PMID:Erythropoietin and renin after renal transplantation. 78 10

Various factors are involved in the pathogenesis of anemia in dialysis patients. Reduced erythropoiesis is mainly attributed to erythropoietin deficiency. Stimulation of erythropoiesis may be promoted by androgens. Substitution of iron is recommended in case of iron deficiency. As a rule, supplementation of vitamin B12 is not necessary, but administration of folic acid is recommended. Treatment of anemia in renal failure is rendered more effective by increased technical efficiency in hemodialysis permitting a relatively protein-rich diet. Blood transfusions are not necessary during routine treatment of dialysis. Since bilateral nephrectomy will always provoke severe anemia, it should be reserved to special cases of severe hypertension. Until now, no conservative therapy has been developed which would allow optimal treatment of anemia in dialysis patients. Successful renal transplantation still is, and will be, the best therapeutic intervention.
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PMID:[Anemia in terminal kidney failure. Pathogenesis and therapy]. 83 56

Plasma activities of renin and erythropoietin were determined in the renal veins of the right and left kidneys of hypertensive patients. The patients were divided into the following groups either according to the origin of the hypertension (group 1: control for essential hypertension, group 2: renovascular hypertension) or according to the hormone levels (group 3: renin activity exceeding 10 ng/litre in at least one of the renal veins and group 4: erythropoietin activity higher than 4% 59Fe incorporation in at least one of the renal veins). In groups 1, 2 and 3 a statistically significant difference in renin activity was found between the kidney with the higher renin activity and that with the lower activity. However, in group 4, the side, which showed elevated erythropoietin values also had higher renin activity as compared to the essential hypertensive group. Erythropoietin activity probably does not parallel the increased renin activity found in renovascular hypertension or in some cases of non-renovascular hypertension. However, in several cases of renal vascular alterations, both systems can be activated simultaneously.
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PMID:Activity of erythropoietin and renin in renal venous blood of hypertensive patients. 95 3

Hypertension is the main side effect developing in patients suffering from renal anemia who are treated with recombinant human erythropoietin (rhEPO). We investigated the effect of rhEPO on the vascular tone of rabbit aorta. rhEPO had no direct vasoconstrictor effect, but it enhanced norepinephrine (NE)-induced contractions of rabbit aortic rings. Relaxations to acetylcholine (ACh, 1 microM) were unaltered in the presence or absence of rhEPO, indicating that the endothelium-dependent NO pathway was not affected by rhEPO. In rings of human renal artery and rabbit aorta, rhEPO (200 U/ml) increased the synthesis of constrictor prostanoids. The cyclooxygenase inhibitors indomethacin and aspirin abolished the increase in prostanoid production. However, they did not completely suppress the rhEPO-induced enhancement of NE contractions in rabbit aorta. We further investigated the effect of rhEPO on prostanoid and endothelin-1 synthesis in cultured human endothelial cells. Endothelial cells from human umbilical veins (HUVEC) were isolated and cultured. After incubation with rhEPO, the formation of prostaglandin (PG) I2 (analyzed as its stable metabolite 6-keto-PGF1 alpha), PGF2 alpha, PGE2, thromboxane (Tx) B2, and of endothelin-1 (ET-1) was measured by radioimmunoassay (RIA). rhEPO (200 U/ml) increased the formation of PGF2 alpha and TxB2 and decreased the formation of PGI2 in HUVEC. The release of ET-1 was increased by nearly 90% in the presence of rhEPO (200 U/ml). We conclude that a shift in the balance of constrictor and relaxing prostanoids as well as an increased synthesis of ET-1 may contribute to the hypertensive side effect of rhEPO therapy. ET-1 may at least in part be responsible for the unexpectedly low inhibitory effect of indomethacin on rhEPO-enhanced contractions of rabbit aorta.
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PMID:Endothelin release and shift in prostaglandin balance are involved in the modulation of vascular tone by recombinant erythropoietin. 128 78

Renal erythropoietin production is dependent on local oxygen content of blood which activates so called "oxygen sensors". Taking into consideration altered local renal blood supply in patients with arterial hypertension in the course of arteritis (HA) and from the other side contribution of the renin-angiotensin system in both pathogenesis of hypertension and regulation of erythropoietin production it seemed plausible to undertake this study. The aim of the study was to determine whether and in what extent patients with HA and healthy subjects differ in EPO secretion and whether EPO serum level is related in this patients to renin response to dietary sodium restriction and upright position of the body. 18 patients with HA and 12 healthy subjects were investigated. In all subjects haematocrit value, haemoglobin concentration, erythrocyte count, sodium, potassium, creatinine, iron, ferritin serum levels, total iron binding capacity, plasma renin activity (PRA), erythropoietin serum level and mean arterial blood pressure (MAP) were measured in basic conditions (normal sodium diet). Additionally PRA, EPO and MAP were measured after dietary sodium restriction to 10-20 mmol Na/24 hrs for three days and upright position of the body for three hours. Patients with HA had insignificantly lower serum EPO concentrations than healthy subjects and both studied groups did not differ in haematocrit value and determinants of iron metabolism except of significantly higher ferritin concentration in HA. After dietary sodium restriction and upright position of the body significant rise in PRA and no significant changes in EPO level were found in studied groups.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[The role of erythropoietin in blood pressure regulation in patients with arteritis]. 130 May 62

Human recombinant erythropoietin (r-HuEPO, EprexR) was administered to 8 children with chronic renal failure and high transfusion requirement. The hormone was given i.v. 2-3 times per week at the end of the dialysis. The selected initial dose (160 U/kg/week) was gradually raised up to a maximum of 400 U/kg/week. Anaemia normalised by the tenth week. The aimed target haematocrit was 0.33, the average maintenance dose was 250-300 U/kg/week. The absolute reticulocyte count seemed to be a more sensitive indicator of the actual erythropoietin effect than the haematocrit level. No major adverse effects (convulsion, progressive hypertension, thrombosis) were observed during treatment with r-HuEPO. The need for transfusions decreased dramatically, no transfusion was needed following the second week of treatment. The general condition improved substantially. In one hyperimmunized child the cytotoxic antibody titer decreased by 75 per cent.
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PMID:The use of human recombinant erythropoietin in children on chronic dialysis. 130 91

To investigate the pathophysiology of hypertension in patients receiving recombinant human erythropoietin (rHuEpo) we studied its effects on the renin-aldosterone axis of chronic haemodialysis (HD) patients not receiving antihypertensive drugs. Nine severely anaemic normotensive HD patients received rHuEpo 50 U/kg bodyweight, thrice weekly after each HD. The dose was increased by 25 U/kg bodyweight every 4 weeks to a maximum of 100 U/kg or until an increase of Hb or Hct of 2 g/dl or 7% was achieved. Blood samples were taken after 30 min supine rest and while seated 10 min later after gentle ambulation. Results expressed as mean +/- SEM: therapy in normotensive HD patients by a negative feedback loop, before the development of hypertension.
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PMID:Suppression of the renin-angiotensin-aldosterone axis with erythropoietin therapy by a negative feedback loop. 131 71


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