[3H]Forskolin binding to cardiac adenylate cyclase in guinea pigs chronically infused with isoproterenol

Lynne McMartin, Roger J. Summers

Research output: Contribution to journalArticleResearchpeer-review

Abstract

Guinea pigs were infused with the β-adrenoceptor agonist isoproterenol (400 μg/kg/hr, 7 days) and cardiac adenylate cyclase was detected using [3H]forskolin. Two populations of [3H]forskolin binding sites were present in heart, the affinities (KD 2 nM and 280 nM) and densities (Bmax 9 and 900 fmol/mg protein) of which were unchanged by isoproterenol infusion compared with vehicle (l mM HCl). The autoradiographic localisation of [3H]forskolin binding was also unchanged. The G protein activators NaF 10 mM and 5′-guanylylimidodiphosphate (Gpp(NH)p) 10 μM increased [3H]forskolin binding in heart from vehicle-treated animals by 100% and 80% respectively. NaF-stimulated binding was unchanged in isoproterenol-treated animals, however, Gpp(NH)p-stimulated binding was reduced by 35% which may indicate an increased influence of Gi.

Original languageEnglish
Pages (from-to)1039-1049
Number of pages11
JournalLife Sciences
Volume57
Issue number11
DOIs
Publication statusPublished - 4 Aug 1995
Externally publishedYes

Keywords

  • adenylate cyclase
  • isoproterenol
  • [H]forskolin

Cite this

@article{9a4d787feec74cdeb461d41da3a2d150,
title = "[3H]Forskolin binding to cardiac adenylate cyclase in guinea pigs chronically infused with isoproterenol",
abstract = "Guinea pigs were infused with the β-adrenoceptor agonist isoproterenol (400 μg/kg/hr, 7 days) and cardiac adenylate cyclase was detected using [3H]forskolin. Two populations of [3H]forskolin binding sites were present in heart, the affinities (KD 2 nM and 280 nM) and densities (Bmax 9 and 900 fmol/mg protein) of which were unchanged by isoproterenol infusion compared with vehicle (l mM HCl). The autoradiographic localisation of [3H]forskolin binding was also unchanged. The G protein activators NaF 10 mM and 5′-guanylylimidodiphosphate (Gpp(NH)p) 10 μM increased [3H]forskolin binding in heart from vehicle-treated animals by 100{\%} and 80{\%} respectively. NaF-stimulated binding was unchanged in isoproterenol-treated animals, however, Gpp(NH)p-stimulated binding was reduced by 35{\%} which may indicate an increased influence of Gi.",
keywords = "adenylate cyclase, isoproterenol, [H]forskolin",
author = "Lynne McMartin and Summers, {Roger J.}",
year = "1995",
month = "8",
day = "4",
doi = "10.1016/0024-3205(95)02049-O",
language = "English",
volume = "57",
pages = "1039--1049",
journal = "Life Sciences",
issn = "0024-3205",
publisher = "Elsevier",
number = "11",

}

[3H]Forskolin binding to cardiac adenylate cyclase in guinea pigs chronically infused with isoproterenol. / McMartin, Lynne; Summers, Roger J.

In: Life Sciences, Vol. 57, No. 11, 04.08.1995, p. 1039-1049.

Research output: Contribution to journalArticleResearchpeer-review

TY - JOUR

T1 - [3H]Forskolin binding to cardiac adenylate cyclase in guinea pigs chronically infused with isoproterenol

AU - McMartin, Lynne

AU - Summers, Roger J.

PY - 1995/8/4

Y1 - 1995/8/4

N2 - Guinea pigs were infused with the β-adrenoceptor agonist isoproterenol (400 μg/kg/hr, 7 days) and cardiac adenylate cyclase was detected using [3H]forskolin. Two populations of [3H]forskolin binding sites were present in heart, the affinities (KD 2 nM and 280 nM) and densities (Bmax 9 and 900 fmol/mg protein) of which were unchanged by isoproterenol infusion compared with vehicle (l mM HCl). The autoradiographic localisation of [3H]forskolin binding was also unchanged. The G protein activators NaF 10 mM and 5′-guanylylimidodiphosphate (Gpp(NH)p) 10 μM increased [3H]forskolin binding in heart from vehicle-treated animals by 100% and 80% respectively. NaF-stimulated binding was unchanged in isoproterenol-treated animals, however, Gpp(NH)p-stimulated binding was reduced by 35% which may indicate an increased influence of Gi.

AB - Guinea pigs were infused with the β-adrenoceptor agonist isoproterenol (400 μg/kg/hr, 7 days) and cardiac adenylate cyclase was detected using [3H]forskolin. Two populations of [3H]forskolin binding sites were present in heart, the affinities (KD 2 nM and 280 nM) and densities (Bmax 9 and 900 fmol/mg protein) of which were unchanged by isoproterenol infusion compared with vehicle (l mM HCl). The autoradiographic localisation of [3H]forskolin binding was also unchanged. The G protein activators NaF 10 mM and 5′-guanylylimidodiphosphate (Gpp(NH)p) 10 μM increased [3H]forskolin binding in heart from vehicle-treated animals by 100% and 80% respectively. NaF-stimulated binding was unchanged in isoproterenol-treated animals, however, Gpp(NH)p-stimulated binding was reduced by 35% which may indicate an increased influence of Gi.

KW - adenylate cyclase

KW - isoproterenol

KW - [H]forskolin

UR - http://www.scopus.com/inward/record.url?scp=0028991390&partnerID=8YFLogxK

U2 - 10.1016/0024-3205(95)02049-O

DO - 10.1016/0024-3205(95)02049-O

M3 - Article

VL - 57

SP - 1039

EP - 1049

JO - Life Sciences

JF - Life Sciences

SN - 0024-3205

IS - 11

ER -