Pharmacological effects in animals and normal human subjects of the diuretic amiloride hydrochloride (MK‐870&gt;

Baba, W. I.; Lant, A. F.; Smith, Anthony J.; Townshend, Mary M.; Wilson, Graham M.

doi:10.1002/cpt196893318

Cited by 59 publications

(20 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Amiloride enihanced net secretion (or inhibited absorption) of l)icarbonate which is consistenit with its known renal actioin to inhibit uirinary acidificationi (23,24). The iieclhanisimi of actioni of' an-miloride on bicarbonate transport is unclear.…”

Section: Resultsmentioning

confidence: 99%

Bicarbonate Secretion by Rabbit Cortical Collecting Tubules in Vitro

McKinney¹,

Burg²

1978

J. Clin. Invest.

106

View full text Add to dashboard Cite

A B S T R A C T We previously reported that rabbit renal cortical collecting tubules can secrete bicarbonate in vitro (i.e., there can be net transport from bath to lumen, causing the concentration in the lumen to increase). Net bicarbonate secretion was observed most often when rabbits had been pretreated with NaHCO3 and were excreting alkaline urine before being killed for experiments. The purpose of the present studies was to elucidate the mechanism involved by testing the effects of ion substitutions and drugs on collecting tubules that were secreting bicarbonate. Acetazolamide inhibited net bicarbonate secretion, suggesting that the process is dependent upon carbonic anhydrase. Net bicarbonate secretion also decreased when sodium in the perfusate and bath was replaced by choline, but not when chloride was replaced by nitrate or methylsulfate. Ouabain had no significant effect. Amiloride caused net bicarbonate secretion to increase. The rate of net secretion did not correlate with transepithelial voltage. The results are compared to those in turtle urinary bladders that also secrete bicarbonate. There are no direct contradictions between the results in the two tissues, i.e., in turtle bladders acetazolamide also inhibited bicarbonate secretion and ouabain had no effect. Nevertheless, it seems unlikely that net secretion of bicarbonate by collecting tubules involves specific exchange for chloride, as has been proposed for turtle bladders, because replacement of chloride by other anions did not inhibit bicarbonate secretion by collecting tubules. It was previously shown that the collecting tubules in vitro also may absorb bicarbonate, especially when the rabbits have been treated with NH4C1 and are excreting acid urine before being killed.

show abstract

Section: Resultsmentioning

confidence: 99%

Bicarbonate Secretion by Rabbit Cortical Collecting Tubules in Vitro

McKinney¹,

Burg²

1978

J. Clin. Invest.

106

View full text Add to dashboard Cite

show abstract

“…Amiloride, a potassium-sparing diuretic, is believed to act in the distal tubule of the nephron, where it is reported to exert a mild diuretic and natriuretic action and a marked potassium-sparing effect (Baba, Lont, Smith, Townshend & Wilson, 1968;Duarte, Chomety & Giebisch, 1971).…”

Section: Introductionmentioning

confidence: 99%

Dose‐dependent reduction in renal magnesium clearance by amiloride during frusemide‐induced diuresis in rats

Devane

Ryan

1983

British J Pharmacology

View full text Add to dashboard Cite

1The effects of the potassium-sparing diuretic, amiloride, on fractional magnesium excretion were investigated at four doses (0.02, 0.08, 0.20 and 2.00mgkg1lh-1) during frusemide-induced diuresis. 2 Amiloride caused a dose-dependent reduction in the fractional excretion of both magnesium and potassium, whereas the effects of amiloride, over the same dose range, on fractional sodium and calcium excretion were not dose-dependent. 3 The results indicate that amiloride exerted a specific renal action to alter magnesium and potassium transport dissociated from effects on sodium excretion.

show abstract

“…However, if the sodium delivery to the distal nephron can be increased by concomitant administration of a more proximally acting diuretic, the diuretic effect of amiloride can be increased, as shown by the potentiation of the diuretic effect of amiloride and thiazide [70. 71] or amiloride and furosemide [14,76], Some sodium reabsorption in the distal nephron occurs in the absence of mineralocorticoid stimulation, and this sodium trans port can also be inhibited by amiloride, as demonstrated by the effect of this drug in adrenalectomized animals [3,70], However, sodium reabsorption is largely stimulated in the distal nephron by mineralocorticoids, partly by means of an increase of the amiloride-sensitive apical membrane Na+ conduc tance (see next chapter). Thus, the diuretic effect of amiloride is enhanced by high levels of mineralocorticoids, such as those pro duced by previous sodium depletion [14], Vasopressin (ADH) also stimulates sodi um transport in amphibian 'tight' epithelia [125.…”

Section: Effect On Na* Tubular Reabsorptionmentioning

confidence: 99%

Potassium-Sparing Diuretics

Horisberger

Giebisch²

1987

Kidney Blood Press Res

View full text Add to dashboard Cite

Amiloride, triamterene, and the spirolactones are potassium-sparing diuretics which act on the distal parts of the nephron, from the late distal tubule to the collecting duct. In these segments, active sodium reabsorption occurs through the following mechanism: sodium ions enter the cell through specific channels present in the luminal membrane and are extruded out of the cell into the peritubular medium by a sodium-potassium exchange pump, the Na-K-ATPase. Amiloride in micromolar concentrations reduces the sodium transport by blocking the luminal membrane sodium channel. Triamterene has a similar effect, although with a lower affinity; the available studies do not allow to determine if an inhibitory effect of triamterene on the Na-K-ATPase plays an additional role in its diuretic action. The spirolactones are competitive inhibitors of aldosterone, the mineralocorticoid hormone which

show abstract

Pharmacological effects in animals and normal human subjects of the diuretic amiloride hydrochloride (MK‐870>

Abstract: Pharmacological effects in animals and normal human subjects of the diuretic amiloride hydrochloride (MK-870>

Cited by 59 publications

References 2 publications

Bicarbonate Secretion by Rabbit Cortical Collecting Tubules in Vitro

Bicarbonate Secretion by Rabbit Cortical Collecting Tubules in Vitro

Dose‐dependent reduction in renal magnesium clearance by amiloride during frusemide‐induced diuresis in rats

Potassium-Sparing Diuretics

Contact Info

Product

Resources

About