Dopamine-1 receptors in the proximal convoluted tubule of Dahl rats: Defective coupling to adenylate cyclase

K. Ohbu, Frederick J. Kaskel, S. Kinoshita, R. A. Felder

Research output: Contribution to journalArticle

33 Citations (Scopus)

Abstract

We have previously reported a defect in the coupling of the renal dopamine-1 receptor (D1) to adenylate cyclase (AC) in the proximal convoluted tubule (PCT) of the spontaneously hypertensive rat (Okamoto-Aoki strain). To determine if this defect is present in another model of hypertension, we microdissected PCTs from Dahl salt-sensitive (DSS) and Dahl salt-resistant (DSR) rats on low- or high-NaCl diet. The ability of two selective D1 agonists, fenoldopam and SND-919-C12, and forskolin to stimulate AC activity in PCT was determined in each of the four groups of rats. Fenoldopam (10-7 M) and SND-919-C12 (10-6 M) failed to stimulate AC activity in the PCT of DSS rats whether on a low- or high-NaCl diet. In DSR rats, however, both fenoldopam and SND-919-C12 stimulated AC activity by 289- 320% and 220-270%, respectively, whether on a low- or high-NaCl intake. Forskolin (10-5 M), which directly stimulates AC activity, increased AC activity in all four groups. These studies show that in DSS rats the D1 receptor in the PCT fails to respond to D1 agonists. This defect is not a consequence of the hypertension because it was present in the DSS rats on a low-salt diet and before blood pressure elevation.

Original languageEnglish (US)
JournalAmerican Journal of Physiology - Regulatory Integrative and Comparative Physiology
Volume268
Issue number1 37-1
StatePublished - 1995
Externally publishedYes

Fingerprint

Inbred Dahl Rats
proximal tubules
adenylate cyclase
Dopamine Receptors
dopamine
Adenylyl Cyclases
sodium chloride
Fenoldopam
receptors
salts
rats
Dopamine Agonists
Colforsin
forskolin
hypertension
agonists
Diet
Hypertension
Sodium-Restricted Diet
low sodium diet

ASJC Scopus subject areas

  • Physiology
  • Agricultural and Biological Sciences(all)

Cite this

@article{ab6463b5b6b84729821536bc39003b7e,
title = "Dopamine-1 receptors in the proximal convoluted tubule of Dahl rats: Defective coupling to adenylate cyclase",
abstract = "We have previously reported a defect in the coupling of the renal dopamine-1 receptor (D1) to adenylate cyclase (AC) in the proximal convoluted tubule (PCT) of the spontaneously hypertensive rat (Okamoto-Aoki strain). To determine if this defect is present in another model of hypertension, we microdissected PCTs from Dahl salt-sensitive (DSS) and Dahl salt-resistant (DSR) rats on low- or high-NaCl diet. The ability of two selective D1 agonists, fenoldopam and SND-919-C12, and forskolin to stimulate AC activity in PCT was determined in each of the four groups of rats. Fenoldopam (10-7 M) and SND-919-C12 (10-6 M) failed to stimulate AC activity in the PCT of DSS rats whether on a low- or high-NaCl diet. In DSR rats, however, both fenoldopam and SND-919-C12 stimulated AC activity by 289- 320{\%} and 220-270{\%}, respectively, whether on a low- or high-NaCl intake. Forskolin (10-5 M), which directly stimulates AC activity, increased AC activity in all four groups. These studies show that in DSS rats the D1 receptor in the PCT fails to respond to D1 agonists. This defect is not a consequence of the hypertension because it was present in the DSS rats on a low-salt diet and before blood pressure elevation.",
author = "K. Ohbu and Kaskel, {Frederick J.} and S. Kinoshita and Felder, {R. A.}",
year = "1995",
language = "English (US)",
volume = "268",
journal = "American Journal of Physiology - Renal Fluid and Electrolyte Physiology",
issn = "1931-857X",
publisher = "American Physiological Society",
number = "1 37-1",

}

TY - JOUR

T1 - Dopamine-1 receptors in the proximal convoluted tubule of Dahl rats

T2 - Defective coupling to adenylate cyclase

AU - Ohbu, K.

AU - Kaskel, Frederick J.

AU - Kinoshita, S.

AU - Felder, R. A.

PY - 1995

Y1 - 1995

N2 - We have previously reported a defect in the coupling of the renal dopamine-1 receptor (D1) to adenylate cyclase (AC) in the proximal convoluted tubule (PCT) of the spontaneously hypertensive rat (Okamoto-Aoki strain). To determine if this defect is present in another model of hypertension, we microdissected PCTs from Dahl salt-sensitive (DSS) and Dahl salt-resistant (DSR) rats on low- or high-NaCl diet. The ability of two selective D1 agonists, fenoldopam and SND-919-C12, and forskolin to stimulate AC activity in PCT was determined in each of the four groups of rats. Fenoldopam (10-7 M) and SND-919-C12 (10-6 M) failed to stimulate AC activity in the PCT of DSS rats whether on a low- or high-NaCl diet. In DSR rats, however, both fenoldopam and SND-919-C12 stimulated AC activity by 289- 320% and 220-270%, respectively, whether on a low- or high-NaCl intake. Forskolin (10-5 M), which directly stimulates AC activity, increased AC activity in all four groups. These studies show that in DSS rats the D1 receptor in the PCT fails to respond to D1 agonists. This defect is not a consequence of the hypertension because it was present in the DSS rats on a low-salt diet and before blood pressure elevation.

AB - We have previously reported a defect in the coupling of the renal dopamine-1 receptor (D1) to adenylate cyclase (AC) in the proximal convoluted tubule (PCT) of the spontaneously hypertensive rat (Okamoto-Aoki strain). To determine if this defect is present in another model of hypertension, we microdissected PCTs from Dahl salt-sensitive (DSS) and Dahl salt-resistant (DSR) rats on low- or high-NaCl diet. The ability of two selective D1 agonists, fenoldopam and SND-919-C12, and forskolin to stimulate AC activity in PCT was determined in each of the four groups of rats. Fenoldopam (10-7 M) and SND-919-C12 (10-6 M) failed to stimulate AC activity in the PCT of DSS rats whether on a low- or high-NaCl diet. In DSR rats, however, both fenoldopam and SND-919-C12 stimulated AC activity by 289- 320% and 220-270%, respectively, whether on a low- or high-NaCl intake. Forskolin (10-5 M), which directly stimulates AC activity, increased AC activity in all four groups. These studies show that in DSS rats the D1 receptor in the PCT fails to respond to D1 agonists. This defect is not a consequence of the hypertension because it was present in the DSS rats on a low-salt diet and before blood pressure elevation.

UR - http://www.scopus.com/inward/record.url?scp=0028813475&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0028813475&partnerID=8YFLogxK

M3 - Article

C2 - 7840326

AN - SCOPUS:0028813475

VL - 268

JO - American Journal of Physiology - Renal Fluid and Electrolyte Physiology

JF - American Journal of Physiology - Renal Fluid and Electrolyte Physiology

SN - 1931-857X

IS - 1 37-1

ER -