Regulation of rat renal α2B-adrenergic receptors by potassium depletion

J. Cameron Muir, Liping Huang, Jeffrey K. Harrison, Diane L. Rosin, Mark D. Okusa

Research output: Contribution to journalArticle

Abstract

Potassium depletion and α2-adrenergic receptor (α2-AR) agonists produce similar physiological effects on renal function. Both stimuli increase Na-H exchange in proximal tubule cells, inhibit water transport in collecting tubule cells, and alter blood pressure regulation. The purpose of this study was to determine whether potassium depletion and renal α2-AR subtype expression were linked. Kidney membrane proteins and RNA were harvested from anesthetized rats fed a potassium-deficient diet for 4-20 days (LK 4 to LK 20). Using a selective α2-AR antagonist, [3H]MK-912, we observed that potassium depletion led to a dramatic increase in maximum binding (270% of control) without a change in dissociation constant. Competitive binding studies in LK 14 kidney membranes employing chlorpromazine, prazosin, and oxymetazoline suggested that the increase in α2-ARs in response to potassium depletion was due primarily to an increase in the B subtype of α2-AR. Northern blot analysis demonstrated that renal α2B-AR mRNA levels increased (190% of control) after 4 or 14 days on a potassium-deficient diet. In contrast, there was no difference in steady-state α2A-receptor protein levels by Western blot analysis. We conclude that potassium depletion selectively increases the expression of the B subtype of α2-AR with no detectable effect on α2A-AR expression.

Original languageEnglish (US)
JournalAmerican Journal of Physiology - Renal Fluid and Electrolyte Physiology
Volume266
Issue number2 35-2
StatePublished - Feb 1994
Externally publishedYes

Fingerprint

Adrenergic Receptors
Potassium
Kidney
L 657743
Oxymetazoline
Diet
Adrenergic Agonists
Adrenergic Antagonists
Competitive Binding
Prazosin
Chlorpromazine
Northern Blotting
Membrane Proteins
Western Blotting
RNA
Blood Pressure
Messenger RNA
Membranes
Water
Proteins

Keywords

  • Adrenoceptors
  • Hypertension
  • Kidney
  • Sodium-hydrogen exchange
  • Vasopressin

ASJC Scopus subject areas

  • Physiology

Cite this

Regulation of rat renal α2B-adrenergic receptors by potassium depletion. / Muir, J. Cameron; Huang, Liping; Harrison, Jeffrey K.; Rosin, Diane L.; Okusa, Mark D.

In: American Journal of Physiology - Renal Fluid and Electrolyte Physiology, Vol. 266, No. 2 35-2, 02.1994.

Research output: Contribution to journalArticle

Muir, J. Cameron ; Huang, Liping ; Harrison, Jeffrey K. ; Rosin, Diane L. ; Okusa, Mark D. / Regulation of rat renal α2B-adrenergic receptors by potassium depletion. In: American Journal of Physiology - Renal Fluid and Electrolyte Physiology. 1994 ; Vol. 266, No. 2 35-2.
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