Molecular biology of P-2Y purinoceptors: Expression in rat heart

1 Application of molecular biology to the study of P-2Y purinoceptors has led to the identification of seven such receptors. Here we briefly review their properties and investigate qualitatively the expression of four rat receptor transcripts in heart. 2 The reverse transcriptase-polymerase chain reaction was used to ascertain whether the rat P2Y(1), P2Y(2), P2Y(4) and P2Y(6) receptor transcripts were expressed in whole heart, neonatal cardiac fibroblasts, neonatal cardiac myocytes and adult cardiac myocytes. 3 All receptor sequences could be amplified from neonatal rat whole heart, with P2Y(6) appearing the most abundant transcript of the four. P2Y(1) is expressed at higher levels in comparison to P2Y(2), P2Y(4) and P2Y(6) in the neonatal myocyte. In the adult myocyte P2Y(1), P2Y(2) and P2Y(6) could be amplified but P2Y(4) could not be detected. In the neonatal fibroblast, P2Y(1) and P2Y(6) appear to be expressed at higher levels than P2Y(2) and P2Y(4). 4 In summary, it is concluded that multiple P2Y receptor subtypes are expressed in heart and that the expression in myocytes changes from the neonate to the adult.