Amiloride interacts with renal. cap alpha. - and. beta. -adrenergic receptors

Journal Article · Wed Jul 01 00:00:00 EDT 1987 · Am. J. Physiol.; (United States)

OSTI ID:6145790

Howard, M J; Mullen, M D; Insel, P A

The authors have used radioligand binding techniques to assess whether amiloride and certain analogues of amiloride (ethylisopropyl amiloride and benzamil) can bind to adrenergic receptors in the kidney. They found that amiloride could compete for (/sup 3/H)rauwolscine (..cap alpha../sub 2/-adrenergic receptors), (/sup 3/H)prazosin (..cap alpha../sub 1/-adrenergic receptors), and (/sup 125/I)iodocyanopindolol (..beta..-adrenergic receptors) binding in rat renal cortical membranes with inhibitor constants of 13.6 /plus minus/ 5.7, 24.4 /plus minus/ 7.4, and 8.36 /plus minus/ 13.5 ..mu..M, respectively. Ethylisopropyl amiloride and benzamil were from 2- to 25-fold more potent than amiloride in competing for radioligand binding sites in studies with these membranes. In addition, amiloride and the two analogues competed for (/sup 3/H)prazosin sites on intact Madin-Darby canine kidney cells and amiloride blocked epinephrine-stimulated prostaglandin E/sub 2/ production in these cells. They conclude that amiloride competes for binding to several classes of renal adrenergic receptors with a rank order of potency of ..cap alpha../sub 2/ > ..cap alpha../sub 1/ > ..beta... Binding to, and antagonism of, adrenergic receptors occurs at concentrations of amiloride that are lower than previously observed nonspecific interactions of this agent.

• Research Organization: Univ. of California, La Jolla (USA)
• OSTI ID: 6145790
• Journal Information: Am. J. Physiol.; (United States), Vol. 253:1
• Country of Publication: United States
• Language: English

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DIURETICS
RADIORECEPTOR ASSAY
KIDNEYS
MEMBRANE TRANSPORT
SYMPATHOMIMETICS
RECEPTORS
DOSE-RESPONSE RELATIONSHIPS
LIGANDS
MEMBRANES
PROSTAGLANDINS
RATS
SOMATIC CELLS
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AUTONOMIC NERVOUS SYSTEM AGENTS
BODY
DRUGS
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MAMMALS
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551001* - Physiological Systems- Tracer Techniques