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)

The mechanisms of metabolic acidosis and hyperkalemia were investigated in a patient with chronic mineralocorticoid-resistant renal hyperkalemia (5.3-6.9 mmol/l), metabolic acidosis (arterial blood pH 7.27, total CO2 17 mmol/l), arterial hypertension, undetectable plasma renin activity (less than 0.10 ng/ml/h), high plasma aldosterone level (32-100 ng/dl), and normal glomerular filtration rate (131 ml/min/1.73 m2). During the hyperkalemic period, urine was highly acidic (pH 4.6-5.0), urinary NH4 excretion (10-13 microEq/min) and urinary net acid excretion (19-24 microEq/min) were not supernormal as expected from a chronic acid load. During NaHCO3 infusion, the maximal tubular HCO3 reabsorption was markedly diminished (19.8 mmol/l glomerular filtrate), and the fractional excretion of HCO3 (FE HCO3) when plasma HCO3 was normalized was 20%. Urine minus blood PCO2 increased normally during NaHCO3 infusion (31 mm Hg), and the urinary pH remained maximally low (less than 5.3) when the buffer urinary excretion sharply increased after NH4Cl load. When serum K was returned toward normal limits, metabolic acidosis disappeared, urinary NH4 excretion rose normally after short NH4Cl loading while the urinary pH remained maximally low (4.9-5.2), the maximal tubular HCO3 reabsorption returned to normal values (24.8 mmol/l glomerular filtrate), and FE HCO3 at normal plasma HCO3 was 1%. Nasal insufflation of 1-desamino-8-D-Arginine Vasopressin (dDAVP) resulted in an acute normalization of the renal handling of K and in an increase in net urinary acid excretion. We conclude that: the effect of dDAVP on renal handling of K may be explained by the reversal of the distal chloride shunt and/or an increase in luminal membrane conductance to K; the distal acidification seems to be normal which in the event of distal chloride shunt impairing distal hydrogen secretion might be explained by the presence of systemic acidosis which is a potent stimulus of hydrogen secretion, and metabolic acidosis in the steady state was accounted for by the diminution of bicarbonate reabsorption and ammonia production in the proximal tubule secondary to chronic hyperkalemia.
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PMID:Pseudohypoaldosteronism type II: proximal renal tubular acidosis and dDAVP-sensitive renal hyperkalemia. 377 34

The blood pressure response of 48 hypertensive persons and 32 normotensive persons to elemental calcium (as the carbonate or citrate salt), 1000 mg/d for 8 weeks, was assessed in a randomized, double-blind, placebo-controlled, crossover trial. Compared with placebo, Ca2+ significantly lowered supine systolic blood pressure by 3.8 mm Hg, standing systolic blood pressure by 5.6 mm Hg (p less than 0.02), and supine diastolic blood pressure by 2.3 mm Hg (p less than 0.05) in hypertensive persons. The response in normotensive persons differed significantly from that in hypertensives (p less than 0.03) as their blood pressure was unchanged. Twenty-one (44%) hypertensive and 6 (19%) normotensive persons achieved a reduction in standing systolic arterial pressure of 10 mm Hg or greater. Reported adverse effects were similar between calcium and placebo phases and did not necessitate withdrawal of any patient from the trial. Treatment with 1000 mg/d of oral Ca2+ for 8 weeks represents a safe, well-tolerated, nonpharmacologic intervention that lowers blood pressure in selected patients with mild to moderate hypertension.
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PMID:Blood pressure response to oral calcium in persons with mild to moderate hypertension. A randomized, double-blind, placebo-controlled, crossover trial. 390 59

Evidence to support an association between dietary calcium and blood pressure is presented in this article. Epidemiological surveys, animal experiments, and clinical trials support an inverse relationship between calcium and blood pressure. Several independent diet surveys have reported reduced consumption of calcium by individuals with hypertension. Animal experiments demonstrate an inverse correlation between calcium intake and blood pressure and reveal disturbances in calcium metabolism in hypertensive animals. Similar metabolic disturbances, including lower serum ionized calcium, elevated parathyroid hormone values, and increased urinary calcium excretion, have been reported in human hypertensives compared with normotensives. In addition, three recent experimental trials using 1 gm calcium carbonate supplements demonstrated that increasing calcium intake may reduce blood pressure in some human beings. Further clinical investigations are necessary to define the subset of patients who will respond to calcium therapy. Dietary sources of calcium to provide at least the RDA are recommended. Dairy products are suggested because in addition to calcium, they are valuable sources of potassium and magnesium, which may also lower blood pressure. If a patient cannot tolerate dairy products, oral calcium supplements are indicated.
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PMID:Increasing calcium intake lowers blood pressure: the literature reviewed. 396 54

The mechanisms of metabolic acidosis and hyperkalemia were investigated in a patient with chronic mineralocorticoid-resistant renal hyperkalemia (5.3 to 6.8 mM), metabolic acidosis (arterial blood pH 7.27, total CO2 17 mM), arterial hypertension, undetectable plasma renin activity (less than 0.10 ng/ml/hr), high plasma aldosterone (32 to 100 ng/dl), normal GFR (131 +/- 2.5 ml/min/1.73 m2). During hyperkalemic period, urine was highly acidic (pH 4.6 to 5.0), urinary NH4 excretion (13 mumoles/min) and urinary net acid excretion (24 mumoles/min) were not supernormal as expected from a chronic acid load. During NaHCO3 infusion, maximal tubular HCO3 reabsorption (Tm HCO3) was markedly diminished (19 mmoles/liter GF), fractional excretion of HCO3 (FE HCO3) when plasma HCO3 was normalized, was 20%. Urine-minus-blood PCO2 increased normally (31 mmHg) during NaHCO3 infusion, and urinary pH remained maximally low (less than 5.3) when buffer urinary excretion sharply increased after NH4Cl load. When serum K was returned toward normal limits, metabolic acidosis disappeared, urinary NH4 excretion rose normally after short NH4Cl loading while urinary pH remained maximally low (4.9 to 5.2), Tm HCO3 returned to normal value (24.8 mmoles/liter GF), and FE HCO3 became nil. The renal handling of K was improved with acute NaHCO3 loading and normalized after DDAVP nasal insufflation.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Type II pseudohypoaldosteronism: proximal tubular acidosis and distal tubular hyperkalemia corrected by DDAVP]. 408 72

Two cases of death associated with the use of lithium carbonate are described. The first one concerns a 39-year-old man who was found suddenly dead on his hospital bed. Toxicologic analysis revealed "therapeutic" levels of lithium, nitrazepam, flurazepam, and phenobarbital. The second case involves a 54-year-old woman initially treated for acute cardiac failure and hypertension, who was finally recognized as a case of lithium intoxication; she died of cardiac arrest without evident cardiac lesions and without lithium ions in serum and urine. The medicolegal aspects of both cases are discussed, with reference to the problems of diagnosis, clinical and toxicological correlations, and the medical responsibility.
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PMID:Two cases of death associated with the use of lithium carbonate. 679 20

Regulation of HCO3- and Cl- absorption by arginine vasopressin (AVP) and prostaglandin E2 (PGE2) was examined in isolated, perfused medullary thick ascending limbs (MTAL) from 4- to 7-wk-old spontaneously hypertensive (SHR) and Wistar-Kyoto (WKY) rats. AVP inhibited HCO3- absorption by 50% at 10(-10) M and by 25% at 2 x 10(-12) M in MTAL from both WKY and SHR. Cholera toxin (10(-9) M) or forskolin (10(-6) M) in the bath also inhibited HCO3- absorption by 50% in the SHR. In MTAL from WKY, PGE2 (10(-6) M in the bath) increased HCO3- absorption from 7.1 +/- 0.4 to 12.0 +/- 0.4 pmol.min-1.mm-1 (P < 0.005) and decreased Cl- absorption from 65 +/- 7 to 47 +/- 6 pmol.min-1.mm-1 (P < 0.001) in the presence of 10(-10) M AVP. Under the same conditions, PGE2 had no effect on HCO3- or Cl- absorption in MTAL from SHR. PGE2 also reversed submaximal inhibition of HCO3- absorption by 2 x 10(-12) M AVP in WKY but not in SHR. With 10(-10) M AVP in the bath, phorbol 12-myristate 13-acetate (10(-6) M in the bath) increased HCO3- absorption from 6.6 +/- 0.5 to 12.3 +/- 0.4 pmol.min-1.mm-1 in MTAL from WKY and from 7.6 +/- 0.7 to 12.6 +/- 1.2 pmol.min-1.mm-1 in MTAL from SHR (P < 0.005). These results demonstrate that 1) the effects of PGE2 to stimulate HCO3- absorption and inhibit Cl- absorption in the presence of AVP are absent in MTAL from SHR, 2) the defect may involve an inability of PGE2 to stimulate protein kinase C, and 3) regulation of HCO3- absorption by AVP via adenosine 3',5'-cyclic monophosphate is similar in MTAL from WKY and SHR. The lack of PGE2 inhibition of NaCl absorption in the MTAL may contribute to renal salt retention during the development of hypertension in the SHR.
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PMID:Prostaglandin E2 regulation of ion transport is absent in medullary thick ascending limbs from SHR. 763 31

We describe our preliminary experience with five children who received acetate-free biofiltration, a modification of haemodiafiltration without buffer in the dialysate and simultaneous infusion of bicarbonate through a venous port. Adequacy of haemodialysis (HD) was achieved with 3 h treatments three times per week (mean Kt/v 1.35 +/- 0.29, mean protein catabolic rate (PCR) 1.4 +/- 0.3 mg/dl). During the session, pH increased from 7.4 pre HD to 7.5 post HD. The mean bicarbonate infused as a 0.166 M solution averaged 235 +/- 35 mEq/h. Hypertension did not occur. There were no cramps, hypotension or vomiting. Bicarbonate requirements correlated significantly with dialyser surface area and body weight (r = 0.76, P < 0.001).
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PMID:Paediatric experience with acetate-free biofiltration. 763 33

An increase in Na+/H+ antiporter activity may be involved in hyperproliferation of vascular smooth muscle cells (VSMC) and possibly in the vascular hyperplasia characteristic of hypertension. The present study was designed to examine cell proliferation, Na+/H+ exchange activity, and mRNA levels of the NHE-1 isoform of the Na+/H+ antiporter in cultured aortic VSMC derived from the spontaneously hypertensive rat (SHR) and from normotensive controls, the Wistar/Kyoto rat (WKY). VSMC derived from the SHR grown in early (2 to 6), but not in later (7 to 10) sub-passages, exhibited an increase in [3H]-thymidine incorporation and shorter doubling times as compared to those derived from WKY rats. Na+/H+ exchange activity assayed in the nominal absence of HCO3-/CO2, as the rate of intracellular pH (pHi) recovery after cell acidification was significantly higher in cells from SHR than in those from WKY rats when cells were studied in early sub-passages, but not in cells studied in later sub-passages. In cells grown in early sub-passage, Na+/H+ exchange activity assessed as the initial rate of Na+i accumulation following acute cell acidification was also significantly higher in SHR than WKY cells both in the nominal absence (10.22 +/- 1.15 and 6.98 +/- 1.17 mmol Na+i/90 seconds, P < 0.05, respectively) and in the presence of HCO3-/CO2 (9.94 +/- 1.02 and 5.59 +/- 0.86 mmol Na+/90 seconds, P < 0.01, respectively). There were no detectable differences in the level of steady-state Na+/H+ antiporter (NHE-1) mRNA between VSMC from SHR and WKY rats. Our findings indicate that Na+/H+ exchange activity is increased in cultured aortic VSMC derived from SHR as compared to those derived from WKY rats. The higher functional activity of the Na+/H+ antiporter in VSMC from the SHR is due to a post-transcriptional event(s) and may be related to enhanced growth in culture.
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PMID:Na+/H+ antiporter (NHE-1 isoform) in cultured vascular smooth muscle from the spontaneously hypertensive rat. 773 Nov 74

Modern therapeutic concepts of chronic renal insufficiency are based on observations showing a retardation of progressive renal failure by therapeutic measures. In the context emphasis is now placed on the treatment of arterial hypertension and on the patient's adherence to a protein-restricted diet. In addition to these conservative measures it is important to avoid nephrotoxins, to hydrate the patient sufficiently and to treat advanced hyperlipidemias. Deficiencies of active vitamin D should be treated by oral vitamin D substitution after correction of hyperphosphatemia. In the treatment of the latter, preparations of calcium carbonate are now the preferred mode of treatment. In advanced renal insufficiency it is important to maintain a salt-restricted diet and to treat any attendant hyperkalemia and hyponatremia.
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PMID:[Conservative treatment in chronic kidney insufficiency]. 778 98

Phase I of the Trials of Hypertension Prevention (TOHP) was a randomized, multicenter investigation that included double-blind, placebo-controlled testing of calcium and magnesium supplementation among 698 healthy adults (10.5% blacks and 31% women) aged 30 to 54 years with high-normal diastolic blood pressure (DBP) (80 to 89 mm Hg). Very high compliance (94 to 96% by pill counts) with daily doses of 1 g of calcium (carbonate), 360 mg of magnesium (diglycine), or placebos was corroborated for the active supplements by significant net increases in all urine and serum compliance measures in white men and for urine compliance measures in white women. Overall, neither calcium nor magnesium produced significant changes in blood pressure at 3 and 6 months. Analyses stratified by baseline intakes of calcium, magnesium, sodium, or initial blood pressures also showed no effect of supplementation. These analyses suggested that calcium supplementation may have resulted in a DBP decrease in white women and that response modifiers in this subgroup might have included lower initial urinary calcium levels, urinary sodium levels, or lower body mass index. However, overall analyses indicated that calcium and magnesium supplements are unlikely to lower blood pressure in adults with high-normal DBP. The subgroup analyses, useful to formulate hypotheses, raise the possibility of a benefit to white women, which requires testing in future trials.
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PMID:Lack of blood pressure effect with calcium and magnesium supplementation in adults with high-normal blood pressure. Results from Phase I of the Trials of Hypertension Prevention (TOHP). Trials of Hypertension Prevention (TOHP) Collaborative Research Group. 779 37


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