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Evidence for a nucleotide receptor on adrenal medullary endothelial cells linked to phospholipase C and phospholipase D
Author(s) -
Purkiss John R.,
Wilkinson Graeme F.,
Boarder Michael R.
Publication year - 1993
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.1476-5381.1993.tb13501.x
Subject(s) - phospholipase c , uridine triphosphate , inositol phosphate , biology , biochemistry , p2y receptor , agonist , receptor , nucleotide , inositol , p2 receptor , chemistry , endocrinology , medicine , gene
1 We have investigated whether the ‘atypical’ P 2 ‐purinoceptor previously described on adrenal microvasculature endothelial cells is a nucleotide receptor (responds to pyrimidines and purines) and is linked to phospholipase D as well as phospholipase C. 2 Cultured bovine adrenal medullary endothelial (BAME) cells responded to the pyrimidine UTP, as well as the purines. The total [ 3 H]‐inositol phosphate responses were with a rank order of UTP > ATP‐ = adenosine 5′‐O‐(3‐thio‐triphosphate) (ATPγS) >> 2MeSATP. The selective P 2x agonist β, γ‐methylene ATP was inactive. 3 Construction of dose‐response curves to ATP, ATPγS and UTP in the presence and absence of additional agonists showed that responses to ATPγS and UTP were not additive, nor were those to UTP and ATP. This suggests that purines and pyrimidines acted via a common nucleotide receptor. 4 32 P‐labelled BAME cells, in the presence of butanol, produced [ 32 P]‐phosphatidylbutanol (PBut) when stimulated with ATPγS or the protein kinase C activator, tetradecanoyl phorbol acetate (TPA). 5 Cells labelled with [ 3 H]‐palmitate and stimulated in the presence of butanol generated [ 3 H]‐PBut with the same order of agonist potencies seen for inositol phosphate responses. 6 The protein kinase C inhibitor, Ro 31–8220, abolished TPA and agonist stimulation of [ 3 H]‐PBut production. 7 These observations, and our related studies on bovine aortic endothelial cells, provide the first demonstration of a phospholipase C linked nucleotide receptor on vascular endothelial cells. It is concluded that BAME cells express a nucleotide receptor linked to phospholipase C and phospholipase D, but that activation of phospholipase D is probably down‐stream of phospholipase C.