Effects of Selective vs. Nonselective Cyclooxygenase Inhibition on Dynamic Renal Potassium Excretion: A Randomized Trial

2008 ◽  
Vol 84 (2) ◽  
pp. 208-211 ◽  
Author(s):  
RA Preston ◽  
D Afshartous ◽  
AB Alonso
1987 ◽  
Vol 252 (1) ◽  
pp. F60-F64 ◽  
Author(s):  
L. Rossetti ◽  
G. Klein-Robbenhaar ◽  
G. Giebisch ◽  
D. Smith ◽  
R. DeFronzo

The effect of insulin on renal potassium excretion was examined by employing the euglycemic insulin clamp technique in combination with renal clearance measurements. While euglycemia was maintained, insulin was infused at rates of 4.8 (n = 7) and 12 (n = 5) mU X kg-1 X min-1. Steady-state plasma insulin levels of 164 +/- 8 and 370 +/- 15 microU/ml were achieved in the low- and high-dose studies, respectively. Base-line plasma potassium concentration declined progressively by a mean of 0.14 +/- 0.09 (P less than 0.05) and 0.40 +/- 0.05 meq/liter (P less than 0.01) during the low- and high-dose insulin infusion protocols. Urinary potassium excretion did not change significantly from base line with either insulin dose. Because the decline in plasma potassium concentration could have masked a stimulatory effect of insulin on UKV, six rats received a 12-mU X kg-1 X min-1 euglycemic insulin clamp in combination with an exogenous potassium infusion to maintain the plasma potassium concentration constant at the basal level (4.03 +/- 0.03 vs. 4.05 +/- 0.05 meq/l). Under these conditions of normokalemia, insulin augmented UKV 2.4-fold, from 0.20 +/- 0.05 to 0.48 +/- 0.04 meq/l (P less than 0.001).


1977 ◽  
Vol 233 (5) ◽  
pp. R230-R238 ◽  
Author(s):  
M. C. Moore-ede ◽  
W. S. Schmelzer ◽  
D. A. Kass ◽  
J. A. Herd

Conscious chair-acclimatized squirrel monkeys (Saimiri sciureus) studied with lights on (600 lx) from 0800 to 2000 h daily (LD 12:12) display a prominent circadian rhythm in renal potassium excretion. The characteristics of this rhythm were reproduced in adrenalectomized monkeys by infusing 5 mg cortisol and 0.001 mg aldosterone, or 5 mg cortisol alone, between 0800 and 0900 h daily. When the timing of cortisol adminisration (with or without aldosterone) was phase-delayed by 8 h, the urinary potassium rhythm resynchronized by 80% of the cortisol phase shift, but only after a transient response lasting 3–4 days. With the same daily dose of adrenal steroids given as a continuous infusion throughout each 24 h, urinary potassium excretion showed free-running oscillations no longer synchronized to the light-dark cycle. These results indicate that the cirdacian rhythm of plasma cortisol concentration acts as an internal mediator in the circadian timing system, synchronizing a potentially autonomous oscillation in renal potassium excretion to environmental time cues and to other circadian rhythms within the animal.


2020 ◽  
Vol 54 (2) ◽  
pp. 120-122
Author(s):  
Mads Ryø Jochumsen ◽  
Lars Poulsen Tolbod ◽  
Michael Borre ◽  
Jørgen Frøkiær ◽  
Kirsten Bouchelouche ◽  
...  

1984 ◽  
Vol 247 (2) ◽  
pp. F331-F338
Author(s):  
L. D. Katz ◽  
J. D'Avella ◽  
R. A. DeFronzo

The effects of beta-agonists (epinephrine, isoproterenol, and ITP) and beta-antagonists (propranolol, metoprolol, and butoxamine) on renal potassium excretion were examined using the isolated perfused rat kidney preparation. Following 30 min of control perfusion, one of the above beta-adrenergic agonists or antagonists was added to the perfusion medium. Following epinephrine, a combined beta 1- and beta 2-agonist, urinary potassium excretion (UKV; 0.55 +/- 0.55 vs. 0.36 +/- 0.04 mueq/min, P less than 0.001) and fractional excretion of potassium (FEK; 24.6 +/- 2.4 vs. 18.2 +/- 2.0%, P less than 0.001) both decreased. When isoproterenol, a nonspecific beta-agonist, was added to the perfusate, UKV (0.49 +/- 0.10 vs. 0.27 +/- 0.04 mueq/min, P less than 0.02) and FEK (29.0 +/- 5.2 vs. 16.3 +/- 2.9%, P less than 0.01) again decreased. ITP, a specific beta 1-agonist also caused a decrease in UKV (0.60 +/- 0.13 vs. 0.39 +/- 0.04 mueq/min, P less than 0.02) and FEK (30.2 +/- 5.1 vs. 17.8 +/- 2.8%, P less than 0.02). In contrast, when propranolol, a nonspecific beta-antagonist, was added to the perfusate, the opposite effects on renal potassium handling were observed. UKV (0.45 +/- 0.05 vs. 0.70 +/- 0.07 mueq/min, P less than 0.001) and FEK (23.0 +/- 2.1 vs. 42.5 +/- 3.1%, P less than 0.001) both increased. Metoprolol (50 ng/ml), a specific beta 1-antagonist, increased UKV (0.56 +/- 0.10 vs. 0.68 +/- 0.15 mueq/min, P less than 0.02) and FEK (31.0 +/- 3.8 vs. 48.0 +/- 7.1%, P less than 0.02). A similar effect was observed when a higher dose of metoprolol (200 ng/ml) was employed.(ABSTRACT TRUNCATED AT 250 WORDS)


1979 ◽  
Vol 2 (5) ◽  
pp. 229-243
Author(s):  
Lawrence Rabinowitz

1983 ◽  
Vol 244 (1) ◽  
pp. F28-F34 ◽  
Author(s):  
D. B. Young ◽  
A. W. Paulsen

The interacting effects of aldosterone and plasma potassium concentration on steady-state renal potassium excretion were studied in two groups of chronically adrenalectomized dogs. In group I (six dogs, 22.9 kg) aldosterone was infused intravenously at 20 micrograms/day while potassium intake was changed in steps of 7-10 days duration from 10 to 30 to 100 meq/day. At the completion of each step, plasma potassium concentration, urinary potassium excretion, and other variables that potentially may affect renal function were measured. In group II (six dogs, 22.2 kg) a similar protocol was followed except that aldosterone was infused at 250 micrograms/day and the potassium intake levels were 30, 100, and 200 meq/day. Plasma potassium concentration and excretion data for the 20 micrograms/day group were: 3.22 +/- 0.26 meq/liter and 5 +/- 1 meq/day, 4.35 +/- 0.08 meq/liter and 21 +/- 2 meq/day, and 5.88 meq/liter and 82 +/- 3 meq/day at the 10, 30, and 100 meq/day intake levels, respectively. For the 250 micrograms/day group the values were: 2.72 +/- 0.18 meq/liter and 28 +/- 7 meq/day, 4.16 +/- 0.14 meq/liter and 71 +/- 8 meq/day, and 4.40 +/- 0.14 meq/liter and 172 +/- 26 meq/day at the 30, 100, and 200 meq/day intake levels. Therefore, the increase in aldosterone infusion rate shifted the relationship between plasma potassium concentration and potassium excretion to the left so that at a given level of plasma potassium a greater amount of potassium was excreted. In the normal range of plasma potassium concentration (4.00-4.40 meq/liter) the increase in aldosterone levels resulted in a four- to eightfold increase in daily potassium excretion.


1985 ◽  
Vol 27 (2) ◽  
pp. 379-387 ◽  
Author(s):  
Michael J. Field ◽  
Gerhard J. Giebisch

Endocrinology ◽  
1983 ◽  
Vol 113 (5) ◽  
pp. 1690-1696 ◽  
Author(s):  
MARGARET JOHNSON BIA ◽  
KAREN TYLER ◽  
RALPH DEFRONZO

1974 ◽  
Vol 85 (3) ◽  
pp. 355-358 ◽  
Author(s):  
Steven F. Weinstein ◽  
David M.E. Allan ◽  
Stanley A. Mendoza

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