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Query: UMLS:C0002871 (anemia)
 52,094 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

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 aim of this report is to offer an explanation for the high incidence of arterial hypertension in women taken hormone contraceptives. The real incidence of this association has been considered in women initially having a normal blood pressure and in others who had high blood pressure before using these contraceptives. The estrogen and progestogen components in hormone contraceptives were analyzed individually in various studies. The most recent investigations seem to indicate that progestogen is the main cause of high blood pressure. Different mechanism that could link hormone contraceptives to high blood pressure were investigated. The renin-angiotensin-aldosterone axis involving the action of estrogens and progestogens on the renin substrate, plasma renin, angiotensin II and aldosterone were analyzed. Another possible mechanism could involve glucocorticoids, altering the metabolism of glucose, pyruvate, cholesterol, and triglycerides, Kidney disease involving renal function, microangiopathic anemia, and renal thromboembolism; hyperactivity of the sympathetic nervous system (noraepinephrine and dopamine-beta-hidroxylase blood levels); prostaglandins; genetic mechanism; and individual mechanism were all taken into consideration. Lastly the priorities of the different systems linking high blood pressure to hormone contraceptives and the relationships between them are analyzed.
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PMID:[Hormonal contraceptives and high blood pressure (author's transl)]. 48 Oct 7

Hemodynamic studies were performed at two levels of dietary sodium intake (10 mmoles/day and 100 mmoles/day for 14 days) in a group of patients (with retained kidneys) on chronic hemodialysis. Plasma renin activity and aldosterone, plasma, and extracellular fluid (ECF) volumes were measured while the patient were at rest. Cardiac output, mean intraarterial pressure, and the calculated total peripheral resistance index were recorded while the patients were at rest and during acute "total" autonomic blockade. On the sodium diet of 10 mmoles/day, normotensive and hypertensive patients had similarly low total blood volumes, low-normal ECF volumes, and similar levels of plasma renin and aldosterone. The resting cardiac output was increased in both groups, but the total peripheral resistance was increased only in the patients with hypertension, in whom peripheral resistance was inappropriately high for the degree of anemia. Six hypertensive patients were studied on both diets. The resting mean arterial pressure was greater on the sodium diet of 100 mmoles/day than on the 10 mmoles/day diet, accompanied by increased in plasma volume, extracellular fluid volume, and cardiac output, but no change in peripheral resistance. During autonomic blockade on either diet, there was a marked fall in blood pressure in the patients with hypertension. This was mainly due to a fall in peripheral resistance which reached levels similar to those seen in the normotensive patients whose resistance was unaltered by blockade. Autonomic factors appear to contribute to the elevated peripheral resistance of hypertensive dialysis patients. In these patients, the effect of a high sodium diet, at least over the time-scale studied here, is to increase blood pressure and cardiac output, without the change in peripheral resistance expected from autoregulation.
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PMID:Autonomic blockade and the Valsalva maneuver in patients on maintenance hemodialysis: a hemodynamic study. 59 40

Patients with chronic glomerulonephritis and mild hypertension show a consistent behaviour in their renin-aldosterone-system. There is a close correlation between the elevation of mean blood pressure and destruction of glomeruli. No correlation has been found between renin values and the degree of hypertension. Thus the cuase of mild hypertension occurring in the early stages of chronic GN remains to be elucidated. Normal PRA values in spite of hypertension and expansion of ECFV accompaning progression of chronic glomerulonephritis could be a sign of "relative hyperreninemia". Apparently various mechanisms are involved in the pathogenesis of renal hypertension. These include sodium retention, increased cardiac output. anemia, renin, aldosterone, prostaglandins, expanded plasma volume and peripheral vasoconstriction. These factors are more or less active in the different stages of hypertension and renal failure.
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PMID:Plasma renin activity (PRA) and aldosterone (PA) in patients with chronic glomerulonephritis (GN) and hypertension. 94 54

The effects of removal of all renal tissue on hematopoiesis, osteodystrophy, blood pressure regulation and metabolic functions are reviewed; and, the indications for, and results of, bilateral nephrectomy are discussed. Nephrectomy results in a more severe anemia in dialysis patients which is poorly responsive to androgen therapy. No differences were detected in the severity of osteodystrophy between nephric and anephric patients. However, bilateral nephrectomy can occasionally result in the acute onset of hypocalcemia. Blood pressure regulation must be accomplished in the absence of a functioning renin-angiotensin system. This is largely on the basis of volume, but changes in vascular tone may also be significant. Little is known about the metabolic consequences of nephrectomies. The effect on substances metabolized by the kidney is an area for further investigation. Kidney tissue should be preserved, if at all possible, and nephrectomy performed only for specific indications.
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PMID:Clinical effects of bilateral nephrectomy. 109 Jan 53

Twenty patients with anemia and massive splenomegaly were studied in order to elucidate the mechanism by which splenomegaly results in plasma volume expansion. In 18 patients, increased plasma volume accounted for most of the anemia. Fourteen patients had an exaggerated renin response to standing, mean 1967 +/- 613 (SE) ng angiotensin ll/100 ml plasma (p less than 0.05). The mean resting forearm blood flow was increased 3.47 +/- 0.32 (SE) ml/100 ml forearm tissue (p less than 0.001). The venous capacitance was normal, as contrasted to a marked decrease in venous capacitance in patients with anemia of comparable degree without splenomegaly. Cardiac indices were increased in 10 of 11 patients (range 4.1-8.1 liters/min/sq m). In nine of ten patients oxygen consumption was increased (range 147-231 ml/min/sq m). Splenectomy was performed on 14 patients. Splenic blood flow was elevated in four of four patients (range 750-2000 ml/min). Splenic A-V oxygen difference was exaggerated in seven of seven patients and in three of three patients splenic indocyanine-green dye dilution curve failed to show an early peak suggestive of A-V shunting in the spleen. Free portal pressure was elevated in 12 of 12 patients and decreased immediately after splenectomy. The intravascular albumin mass decreased in ten patients, was unchanged in three at 2-4 mo after splenectomy, and was accompanied by a rise in the plasma albumin concentration in nine. These data suggest that a flow-induced portal hypertension with expansion of the portal vascular space is an important early hemodynamic change. This finding, together with a decreased peripheral resistance, probably results in a decrease in effective intravascular volume, resulting in stimulation of the renin-angiotensin-aldosterone system and other renal hemodynamic changes necessary for salt and water retention. Splenectomy usually accomplishes a complete reversal of these abnormalities and correction of the anemia.
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PMID:Mechanism of dilutional anemia in massive splenomegaly. 126 Jan 26

The major side effect of rHuEPO is hypertension, which is reported to occur in 10-75% of adult patients. The aim of the present study is to evaluate the effect of rHuEPO on blood pressure in pediatric dialysis patients. Nine CAPD patients (mean age 7.4 +/- 3.6 years) and fourteen HD patients (mean age 13.8 +/- 5.5 years) were treated with rHuEPO. The hematocrits increased significantly from 20.7 +/- 1.8 to 28.3 +/- 4.1 in HD patients and from 19.7 +/- 2.9 to 26.7 +/- 4.4 in CAPD patients. The final maintenance dose required to correct the anemia was 47.6 +/- 11.7 units/kg/week for CAPD patients and 122.6 +/- 75.2 U/kg/week foe HD patients. Six (66.6%) out of nine CAPD patients, and five (35.7%) of fourteen HD patients developed or worsened hypertension. Younger CAPD patients tended to develop hypertension. Correction of anemia was poor in two hypertension-exacerbated patients, since rHuEPO dose increase was withheld for fear of aggravating hypertension. A four-year-old girl developed hypertensive encephalopathy after 13 months of rHuEPO therapy. No difference was observed in plasma level of aldosterone or plasma renin activity. Hypertension is observed frequently among pediatric dialysis patients treated with rHuEPO therapy. Careful monitoring and management of hypertension is required, especially in the first three months of rHuEPO therapy.
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PMID:Erythropoietin associated hypertension among pediatric dialysis patients. 136 45

The hemodynamic hallmark of hypertension complicating the treatment of renal anemia with recombinant human erythropoietin (rHu-EPO) is increased total peripheral vascular resistance, but the mechanisms underlying the arteriolar vasoconstriction are still an enigma. We studied body fluid volumes, plasma renin activity, plasma norepinephrine, and calcium metabolism in platelets in 40 previously normotensive hemodialysis patients before and after 12 weeks of rHu-EPO treatment. Partial correction of anemia caused a rise in arterial pressure (94 +/- 6 mmHg vs 124 +/- 7 mmHg, p less than 0.05) and in platelet cytosolic calcium concentration (113 +/- 5 nM vs 171 +/- 18 nM, p less than 0.05) in eight patients. Hypertensive patients had significantly higher plasma noradrenaline concentrations, but they did not differ significantly in body fluid volumes and plasma renin activities. There was a close correlation between free calcium concentration in platelets and mean arterial pressure in patients developing rHu-EPO-induced-hypertension (r = 0.95). Short-term antihypertensive treatment resulted in a reduction of free calcium concentrations in platelets and a concomitant fall in blood pressure. The main results of the present studies suggest that rHu-EPO-induced hypertension might be associated with altered cellular calcium homeostasis and hyperactivity of the sympathetic nervous system. If rHu-EPO therapy induces alterations of pressor factors or the hormone itself raises the cytosolic calcium not only in platelets but also in vascular smooth muscle cells, altered cellular calcium influx may contribute to the arteriolar vasoconstriction.
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PMID:Correlation of blood pressure in end-stage renal disease with platelet cytosolic free calcium concentration during treatment of renal anemia with recombinant human erythropoietin. 163 25

The authors analysed the dynamics of the activity of the renin-angiotensin-aldosterone, hypophyseal-adrenal, and sympathoadrenal systems in 46 patients during a hemodialysis session according to the type of hemodynamics. No essential changes were encountered in the hormone concentration in patients with normotension and "controllable" hypertension. In patients with "uncontrollable" hypertension the dialysis dehydration was attended by increased activity of the renin-angiotensin-aldosterone system, the level of cortisol and the adrenocorticotropic hormone increased slightly. Daily catecholamine excretion was 2-3.5 times below the lowest normal value. Noradrenaline clearance of the plasma membrane dialyser was 82.1 ml/min. Increase in the concentration of noradrenaline, and the activity of renin and aldosterone were encountered both in hypotension and in arterial hypertension. It is concluded that disturbed water balance, dyselectrolythemia, anemia, infectious complications, etc. are the trigger factor of decompensation of the system of the hormonal hemodynamic regulation. Substitution adrenomimetic therapy for arresting collaptoid reactions is inexpedient. Systematic use of medicinal agents should be avoided in favour of a search for an optimal dialysis regimen, should this prove ineffective the decision should be made in favour of an operation.
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PMID:[The activities of the renin-angiotensin-aldosterone and sympathetic-adrenal systems during hemodialysis]. 165 15

To investigate the mechanisms of hypertension induced by recombinant human erythropoietin (rHuEPO) in patients on hemodialysis (HD), mean blood pressure (MBP), plasma renin activity (PRA), whole blood viscosity, blood volume (BV), cardiac index (CI) and total peripheral resistance index (TPRI) were measured before and after treatment with rHuEPO for 3 months in 9 patients on HD. Pressor responsiveness to exogenous norepinephrine (NE) and angiotensin II (AII) were also compared before and after treatment. Four patients were 'responders' (R) whose MBP increased by more than 10 mmHg, and 5 patients were 'non-responders' (non-R) whose MBP was unchanged or increased by less than 10 mmHg. Initial PRA and TPRI were significantly higher and BV was significantly lower in R than in non-R. After treatment, TPRI was increased in both groups, but CI was decreased in non-R. There was a significant correlation between changes in MBP and blood viscosity to rHuEPO. Pressor responsiveness to NE and AII were significantly enhanced after rHuEPO treatment in responders. These results suggest that inappropriate cardiovascular responses to the correction of anemia, increased blood viscosity, and enhanced pressor responsiveness may participate in the development of rHuEPO-related hypertension.
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PMID:Mechanisms of hypertension induced by erythropoietin in patients on hemodialysis. 179 12


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