title: Distribution of purinergic P2X receptors in the rat heart.
abstract: The distribution of P2X purinergic receptor subtypes has been determined in relation to nerve varicosities in the rat heart with immunohistochemistry. Large clusters (about 1 microm diameter) of co-localised and sometimes co-extensive P2X1 and P2X3 receptors were found at sites of tyrosine hydroxylase (TH) positive axon varicosities in the atrium and the ventricle. Varicosities that were labelled with antibodies to the synaptic vesicle epitope SV2 were frequently labelled also with antibodies to P2X3, P2X5 and P2X6 but not always with antibodies to P2X1. Especially prominent were large numbers of small clusters (about 400 nm diameter) of co-localised P2X2 and P2X5 receptors on the sarcolemma unrelated to nerves at all. During development the 1 day-old heart possessed an abundance of co-localised P2X2 and P2X5 small receptor clusters on the sarcolemma. These observations are discussed in relation to the role of purinergic receptors in the mammalian heart.
authors.affiliation: The Institute for Biomedical Research, The University of Sydney, NSW, Australia.
authors.forename: M A
authors.initials: MA
authors.lastname: Hansen
authors.forename: M R
authors.initials: MR
authors.lastname: Bennett
authors.forename: J A
authors.initials: JA
authors.lastname: Barden
mesh_terms: D000255:Adenosine Triphosphate / Q000032:analysis; D000818:Animals; D000918:Antibody Specificity; D005455:Fluorescent Antibody Technique; D006321:Heart / Q000254:growth & development / Q000294:innervation*; D006325:Heart Atria / Q000737:chemistry; D006352:Heart Ventricles / Q000737:chemistry; D008297:Male; D009206:Myocardium / Q000737:chemistry*; D051381:Rats; D017207:Rats, Sprague-Dawley; D018048:Receptors, Purinergic P2 / Q000032:analysis* / Q000276:immunology; D058469:Receptors, Purinergic P2X; D058477:Receptors, Purinergic P2X3; D058485:Receptors, Purinergic P2X5; D012508:Sarcolemma / Q000737:chemistry; D009435:Synaptic Transmission / Q000502:physiology
chemical_list: C546410:P2rx3 protein, rat; C546467:P2rx5 protein, rat; D018048:Receptors, Purinergic P2; D058469:Receptors, Purinergic P2X; D058477:Receptors, Purinergic P2X3; D058485:Receptors, Purinergic P2X5; C110590:purinoceptor P2X6; D000255:Adenosine Triphosphate