Potassium's cardiovascular protective mechanisms

1995 ◽  
Vol 268 (4) ◽  
pp. R825-R837 ◽  
Author(s):  
D. B. Young ◽  
H. Lin ◽  
R. D. McCabe
Keyword(s):  
Smooth Muscle ◽  
Glomerular Filtration Rate ◽  
Cardiovascular Diseases ◽  
Filtration Rate ◽  
Potassium Concentration ◽  
Plasma Potassium ◽  
Potassium Intake ◽  
Potassium Regulation ◽  
Free Radical Formation

High rates of potassium intake are associated with protection from cardiovascular diseases in populations consuming primitive diets and in vegetarians living in industrialized cultures. In studies in humans and in animals, a strong inverse association between potassium intake and hypertension and stroke has been described. However, acceptance of the putative protective effect has been limited by inadequate understanding of 1) long-term potassium regulation, and 2) mechanisms by which small changes in plasma potassium concentration may affect development of cardiovascular diseases. In this review, we present results from analyses of long-term potassium regulation that indicated 1) changes in potassium intake may result in potassium concentrations from 3.1 to 4.6 mmol/l, and 2) when the initial rate is below normal, potassium concentration is very sensitive to changes in potassium intake rate. In addition, we present results that provide bases for possible mechanisms by which potassium may protect against cardiovascular diseases: 1) increases in potassium inhibit free radical formation from vascular endothelial cells and macrophages; 2) elevation of potassium inhibits proliferation of vascular smooth muscle cells; 3) platelet aggregation and arterial thrombosis are inhibited by elevation of potassium; and 4) renal vascular resistance is reduced and glomerular filtration rate is increased by elevation of plasma potassium. We propose that elevation of dietary potassium intake increases plasma potassium concentration, thereby inhibiting free radical formation, smooth muscle proliferation, and thrombus formation. As a result, the rate of atherosclerotic lesion formation and thrombosis will be diminished. In addition, we propose the increase in glomerular filtration rate will cause a shift in the relationship between arterial pressure and sodium excretion that will lead to a reduction in arterial blood pressure. By these actions, high levels of dietary intake of potassium could provide the observed protection against the cardiovascular diseases that have plagued humankind since we began eating a modern high-sodium, low-potassium diet.

Effects of aldosterone on potassium distribution

1982 ◽  
Vol 243 (5) ◽  
pp. R526-R530
Author(s):  
D. B. Young ◽  
T. E. Jackson
Keyword(s):  
Potassium Concentration ◽  
Correlation Coefficients ◽  
Plasma Potassium ◽  
The Body ◽  
Electrolyte Balance ◽  
Potassium Intake ◽  
Independent Variable ◽  
Total Body ◽  
Total Potassium

To assess the effects of long-term changes in aldosterone on potassium distribution within the body, two groups of experiments were conducted. In the first, seven normal dogs received continuous infusion of aldosterone at a high physiological rate, 250 micrograms/day. Total exchangeable potassium (Ke) and plasma potassium concentration (KP) were measured before and 4 and 6 days after aldosterone infusion. KP fell by 20% while Ke decreased by 8% after 6 days of infusion; the ratio between extracellular and total body potassium had been altered by the aldosterone infusion. In the second study, 10 adrenalectomized dogs received aldosterone infusion first at 50 micrograms/day, then at 250 micrograms/day. While on each level of aldosterone infusion, three levels of potassium intake were given by iv infusion. When the animals were in electrolyte balance at each level of aldosterone and potassium (after at least 7 days on each level of infusion), Ke (expressed as meq/kg) and KP were measured. The two variables were plotted against each other, Ke being the independent variable. Data taken while the dogs received 50 micrograms/day aldosterone were described by the equation, KP = 0.100Ke + 0.055, while those obtained at 250 micrograms/day were fitted by the equation, KP = 0.057Ke + 1.30. The correlation coefficients for the two were 0.778 and 0.760, respectively. The regressions were significantly different at a level of P less than 0.02. Data from the two groups of experiments are consistent with the hypothesis that aldosterone alters the distribution of potassium between the intra- and extracellular spaces, a greater portion of total potassium being intracellular at higher levels of aldosterone.

Effects of sodium intake on steady-state potassium excretion

1984 ◽  
Vol 246 (6) ◽  
pp. F772-F778 ◽  
Author(s):  
D. B. Young ◽  
T. E. Jackson ◽  
U. Tipayamontri ◽  
R. C. Scott
Keyword(s):  
Steady State ◽  
Potassium Concentration ◽  
Sodium Intake ◽  
Plasma Potassium ◽  
Potassium Excretion ◽  
Distal Nephron ◽  
Concentration Data ◽  
Potassium Intake ◽  
Independent Variable ◽  
The Relationship

The effects of changes in sodium intake on the steady-state relationship between plasma potassium concentration and potassium excretion were studied in 15 chronically adrenalectomized dogs. Throughout the experiments the dogs received aldosterone at a rate of 50 micrograms/day and methylprednisolone at 1 mg/day. The relationship between plasma potassium and steady-state potassium excretion was obtained by changing potassium intake from 10 to 30 to 100 meq/day, each level being maintained for 7-10 days. At the conclusion of each period at a given level of potassium intake, plasma potassium and excretion were measured and plotted, plasma potassium being the independent variable. Such a relationship was obtained while the dogs were on three different levels of sodium intake: 10, 100, and 200 meq/day. The curves from the data obtained at 100 and 200 meq/day sodium intake both were shifted to the left of the curve obtained at 10 meq/day (P less than 0.05), although the 100 and 200 meq/day curves were not different from each other. On the basis of these data one could predict that, at a plasma potassium concentration of 4.0 meq/liter, the animals would excrete potassium at a rate of 17 meq/day on a 10 meq/day sodium intake, 37 meq/day on a 100 meq/day sodium intake, and 47 meq/day on a 200 meq/day sodium intake. Urine flow and electrolyte concentration data are consistent with the hypothesis that the sodium intake effect on potassium excretion was mediated through increases in distal nephron flow rate and decreases in distal nephron potassium concentration.

Long-Term Follow-Up of Separate Glomerular Filtration Rate in Partially Obstructed Kidneys

1988 ◽  
Vol 22 (4) ◽  
pp. 327-333 ◽  
Author(s):  
A. Piepsz ◽  
H. R. Ham ◽  
M. Hall ◽  
Y. Thoua ◽  
J. L. Froideville ◽  
...  
Keyword(s):  
Glomerular Filtration Rate ◽  
Glomerular Filtration ◽  
Filtration Rate ◽  
Long Term Follow Up

Protein Intake and Long-term Change in Glomerular Filtration Rate in the Jackson Heart Study

2018 ◽  
Vol 28 (4) ◽  
pp. 245-250 ◽  
Author(s):  
Rakesh Malhotra ◽  
Loren Lipworth ◽  
Kerri L. Cavanaugh ◽  
Bessie A. Young ◽  
Katherine L. Tucker ◽  
...  
Keyword(s):  
Glomerular Filtration Rate ◽  
Glomerular Filtration ◽  
Protein Intake ◽  
Filtration Rate ◽  
Jackson Heart Study ◽  
Term Change ◽  
Heart Study

scholarly journals Long-term renal function and continence status in patients with

2013 ◽  
Vol 1 (4) ◽  
pp. 371 ◽  
Author(s):  
Luis H.P. Braga ◽  
Armando J. Lorenzo ◽  
Sumit Dave ◽  
Maria H. Del-Valle ◽  
Antoine E. Khoury ◽  
...  
Keyword(s):  
Renal Function ◽  
Glomerular Filtration Rate ◽  
Glomerular Filtration ◽  
Filtration Rate ◽  
Urogenital Sinus ◽  
Renal Outcome ◽  
Urinary Continence ◽  
Renal Ultrasound ◽  
Common Channel

Introduction: Urinary continence after cloacal repair is difficult to achieveand renal outcome in patients with cloacal malformations has been scarcelyreported. As a result, we reviewed our experience with cloacal malformationsto determine the status of continence and the long-term renal function in thesechildren.Methods: A retrospective chart review from 1990 to 2003 identified 12 patientswith cloacal malformation (1 posterior, 4 complex and 7 classical) who underwentsurgical reconstruction. The confluence was defined as high (commonchannel ≥ 3 cm) and low (< 3 cm) by cystovaginoscopy. Renal ultrasound,voiding cystouretrogram, renal scan and sacral radiograph were performedin all children. Most patients underwent 1-stage abdominoperineal pull-through,applying the principle of total urogenital sinus mobilization. We collected dataregarding hydronephrosis, vesicoureteral reflux and split differential renal function.Renal outcome was evaluated based on glomerular filtration rate and ageadjustedserum creatinine values (μmol/L). Urinary continence was definedas a dry interval > 4 hours.Results: Patients’ mean age at surgery was 20 months (range 7–29 mo). Ofthe 12 children who underwent cloacal repair, 7 (58.3%) had a common channel≥ 3cm. Renal anomalies were identified in 3 of 12 (25%) girls: there were 2 solitary kidneys and 1 pelvic kidney. Lumbar–sacral radiography demonstrated bony abnormalities in 11 of the 12 (91.6%) cases: hemivertebra in 3 cases, sacral agenesis in 4 cases, hypoplastic sacrum in 3 cases and bifid sacrum in 1 case. Total urogenital sinus mobilization through an abdominoperineal approach in a single stage was performed in 8 girls. Follow-up ranged from 4 to 14 years (mean 8.5 yr). Eight (66.6%) children had dry intervals > 4 hours, 5 (62.5%) of them were on clean intermittent catheterization through aMitrofanoff channel and 1 (12.5%) was through the urethra. The remaining 2 (25%) patients were voiding spontaneously. Three (33.3%) patients were totally incontinent, and 1 (8.3%) patient was awaiting reconstruction. The mean measured glomerular filtration rate was 93.5 mL/min/1.73m2 (range 34–152 mL/min/1.73m2). Four (57.1%) of 7 patients who had a common channel ≥ 3 cm ended up needing augmentation cystoplasty, compared with none of the patients with a common channel < 3 cm (57.1% v. 0%, p = 0.038).Conclusion: Urinary continence can be achieved in most patients with cloacalmalformation at the expense of major reconstructive surgery and despite thepresence of associated urological abnormalities. However, these childrenharbour an important risk for renal impairment later in life and should be closelymonitored.

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