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Coupling of a transfected human brain A 1 adenosine receptor in CHO‐K1 cells to calcium mobilisation via a pertussis toxin‐sensitive mechanism
Author(s) -
Iredale Philip A.,
Alexander Stephen P.H.,
Hill Stephen J.
Publication year - 1994
Publication title -
british journal of pharmacology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.432
H-Index - 211
eISSN - 1476-5381
pISSN - 0007-1188
DOI - 10.1111/j.1476-5381.1994.tb14880.x
Subject(s) - pertussis toxin , transfection , chinese hamster ovary cell , calcium , coupling (piping) , mechanism (biology) , adenosine receptor , receptor , adenosine , microbiology and biotechnology , chemistry , neuroscience , biophysics , biology , medicine , pharmacology , endocrinology , biochemistry , physics , g protein , materials science , agonist , gene , quantum mechanics , metallurgy
1 The presence of A 1 adenosine receptors in CHO‐K1 cells transfected with the human brain A 1 sequence was confirmed by ligand binding studies using 8‐cyclopentyl‐[ 3 H] 1,3‐dipropylxanthine ([ 3 H]‐DPCPX). 2 Alterations in intracellular calcium ([Ca 2+ ] i ) were measured with the calcium‐sensitive dye, fura‐2. 3 N 6 ‐cyclopentyladenosine (CPA), the selective A 1 agonist, and 5′‐N‐ethylcarboxaminoadenosine (NECA), a relatively non‐selective adenosine receptor agonist, elicited rapid, biphasic increases in [Ca 2+ ] i which involved both mobilisation from intracellular stores and calcium entry. 4 The calcium response to CPA was significantly inhibited by the selective A 1 antagonist DPCPX. The non‐selective adenosine receptor, xanthine amino congener (XAC), was less potent. 5 The calcium response to CPA was completely prevented by pretreatment of the cells with pertussis toxin implicating the involvement of G i in the receptor‐mediated response. 6 In summary, we present evidence for the coupling of transfected human brain A 1 adenosine receptors in CHO‐K1 cells to mobilisation of [Ca 2+ ] i via a pertussis toxin‐sensitive G protein.