Effect of epinephrine on renal potassium excretion in the isolated perfused rat kidney

1984 ◽  
Vol 247 (2) ◽  
pp. F331-F338
Author(s):  
L. D. Katz ◽  
J. D'Avella ◽  
R. A. DeFronzo
Keyword(s):  
Rat Kidney ◽  
Fractional Excretion ◽  
Beta Agonist ◽  
Potassium Excretion ◽  
Isolated Perfused Rat Kidney ◽  
Beta Agonists ◽  
Beta Adrenergic Agonists ◽  
Urinary Potassium ◽  
Perfused Rat Kidney ◽  
Renal Potassium Excretion

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)

Comparison of the effects of parathyroid hormone (PTH) and recombinant PTH-related protein on bicarbonate excretion by the isolated perfused rat kidney

1990 ◽  
Vol 126 (3) ◽  
pp. 403-408 ◽  
Author(s):  
A. G. Ellis ◽  
W. R. Adam ◽  
T. J. Martin
Keyword(s):  
Parathyroid Hormone ◽  
Rat Kidney ◽  
Urine Volume ◽  
Clinical Manifestations ◽  
Fractional Excretion ◽  
Bicarbonate Concentration ◽  
Isolated Perfused Rat Kidney ◽  
Amino Terminal ◽  
Fractional Excretion Of Sodium ◽  
Perfused Rat Kidney

ABSTRACT The isolated perfused rat kidney was used to study the effects of amino-terminal fragments of human parathyroid hormone, hPTH(1–34), bovine parathyroid hormone, bPTH(1–84) and of PTH-related proteins, PTHrP(1–34), PTHrP(1–84), PTHrP(1–108) and PTHrP(1–141) on urinary bicarbonate excretion. PTHrP(1–34) (7 nmol/l), bPTH(1–84) (5·5 nmol/l) and hPTH(1–34) (7 nmol/l) had similar effects in increasing bicarbonate excretion with respect to the control. At lower concentrations (0·7 nmol/l) all PTHrP components, but not hPTH(1–34) or bPTH(1–84) increased bicarbonate excretion significantly. Infusions of PTHrP(1–108) and PTHrP(1–141) at 0·7 nmol/l, while associated with a rise in urinary bicarbonate concentration and excretion during the early stages of perfusion, produced a sharp decline in bicarbonate concentration and excretion in the latter part of perfusion. The different peptides produced no significant differences in glomerular filtration rate, fractional excretion of sodium or urine volume. The absence of substantial differences between the effects of hPTH(1–34) and PTHrP(1–34) are as noted in previous studies. The differences between PTHrP(1–108)/PTHrP(1–141) and PTHrP(1–34) demonstrated here are consistent with (1) the clinical manifestations of acidosis in hyperparathyroidism and alkalosis in humoral hypercalcaemia of malignancy, and (2) an independent action of a component of PTHrP beyond amino acids 1–34. Journal of Endocrinology (1990) 126, 403–408

Effect of vasoactive intestinal peptide on isolated perfused rat kidney

1985 ◽  
Vol 249 (5) ◽  
pp. E494-E497 ◽  
Author(s):  
R. M. Rosa ◽  
P. Silva ◽  
J. S. Stoff ◽  
F. H. Epstein
Keyword(s):  
Vasoactive Intestinal Peptide ◽  
Rat Kidney ◽  
Urine Volume ◽  
Fractional Excretion ◽  
Rectal Gland ◽  
Renal Nerves ◽  
Isolated Perfused Rat Kidney ◽  
Fractional Excretion Of Sodium ◽  
Perfused Rat Kidney ◽  
Renal Tubular

Vasoactive intestinal peptide, a polypeptide neurotransmitter, stimulates salt secretion by the mammalian intestine and the rectal gland of the dogfish shark. Because of the recent identification of vasoactive intestinal peptide in renal nerves, the present study was undertaken to investigate its effects on the isolated perfused rat kidney. The addition of vasoactive intestinal peptide to the recirculating perfusate produced a significant increase in urine volume, fractional excretion of sodium, chloride, and potassium, as well as osmolar clearance when compared with control kidneys. These changes associated with addition of vasoactive intestinal peptide occurred without any significant changes in perfusion flow, renal vascular resistance, or inulin clearance. These experiments strongly suggest an action of vasoactive intestinal peptide on renal tubular reabsorption.

Effects of atrial natriuretic peptides on metabolism of arginine vasopressin by isolated perfused rat kidney

1992 ◽  
Vol 263 (2) ◽  
pp. R273-R278
Author(s):  
M. R. Lebowitz ◽  
A. M. Moses ◽  
S. J. Scheinman
Keyword(s):  
Arginine Vasopressin ◽  
Rat Kidney ◽  
Fractional Excretion ◽  
Metabolic Clearance ◽  
Isolated Perfused Rat Kidney ◽  
Perfused Rat Kidney ◽  
Clearance Receptor ◽  
Atrial Natriuretic

Atrial natriuretic peptide (ANP) antagonizes the release and action of arginine vasopressin (AVP) both in vivo and in vitro. We have reported that ANP increases the urinary and metabolic clearances of AVP in normal subjects (A. M. Moses et al. J. Clin. Endocrinol. Metab. 70: 222-229, 1990). To clarify this effect, we perfused isolated rat kidneys in vitro and measured the clearances of AVP for 30 min after the addition of rat ANP [rANP-(1-28), 10(-7) M]. In the perfused kidney, rANP increased the urinary clearance of AVP (UCAVP) from 321 +/- 19 to 417 +/- 20 microliters/min (P less than 0.01) and increased the glomerular filtration rate (GFR) from 558 +/- 28 to 696 +/- 28 microliters/min (P less than 0.01). Fractional excretion of AVP was unchanged. Rates of AVP reabsorption were directly related to filtered AVP, and this relationship was not altered by ANP. ANP did not affect the total organ clearance or the renal metabolic clearance of AVP. The increase in GFR was associated with increases in renal vascular resistance (P less than 0.05), filtration fraction (P less than 0.01), and sodium excretion (P less than 0.001). UCAVP also increased when GFR was raised without ANP by perfusing at higher pressures. The rat ANP clearance receptor agonist [cANP- (4-23), 10(-7) M] did not change GFR or UCAVP. ANP increases UCAVP in the isolated perfused rat kidney. This appears to be a hemodynamic effect of ANP, acting through its biological receptor and not the clearance receptor.(ABSTRACT TRUNCATED AT 250 WORDS)

Validation of a toxicity testing model by evaluating oxygen supply and energy state in the isolated perfused rat kidney

1991 ◽  
Vol 25 (3) ◽  
pp. 195-204 ◽  
Author(s):  
Takano Takehito ◽  
Nakata Kazuyo ◽  
Kawakami Tsuyoshi ◽  
Miyazaki Yoshifumi ◽  
Murakami Masataka ◽  
...  
Keyword(s):  
Oxygen Supply ◽  
Energy State ◽  
Rat Kidney ◽  
Toxicity Testing ◽  
Testing Model ◽  
Isolated Perfused Rat Kidney ◽  
Perfused Rat Kidney

Aldosterone Effects on Renal Function in the Isolated Perfused Rat Kidney

1979 ◽  
Vol 2 (1) ◽  
pp. 1-11
Author(s):  
Richard Solomon ◽  
Patricio Silva ◽  
Franklin H. Epstein
Keyword(s):  
Renal Function ◽  
Rat Kidney ◽  
Isolated Perfused Rat Kidney ◽  
Perfused Rat Kidney

Effect of insulin on renal potassium metabolism

1987 ◽  
Vol 252 (1) ◽  
pp. F60-F64 ◽  
Author(s):  
L. Rossetti ◽  
G. Klein-Robbenhaar ◽  
G. Giebisch ◽  
D. Smith ◽  
R. DeFronzo
Keyword(s):  
Potassium Concentration ◽  
Insulin Dose ◽  
Plasma Potassium ◽  
High Dose ◽  
Base Line ◽  
Potassium Excretion ◽  
Insulin Clamp ◽  
Urinary Potassium ◽  
Plasma Insulin Levels ◽  
Renal Potassium Excretion

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).

EFFECTS OF CYCLOSPORINE ON THE ISOLATED PERFUSED RAT KIDNEY

1987 ◽  
Vol 43 (6) ◽  
pp. 795-799 ◽  
Author(s):  
David R. Luke ◽  
Bertram L. Kasiske ◽  
Gary R. Matzke ◽  
Walid M. Awni ◽  
William F. Keane
Keyword(s):  
Rat Kidney ◽  
Isolated Perfused Rat Kidney ◽  
Perfused Rat Kidney
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