Immunoreactive localisation of P2Y1 receptors within the rat and human nodose ganglia and rat brainstem: comparison with [α33P]deoxyadenosine 5′-triphosphate autoradiography
Section snippets
Experimental procedures
All experiments were performed in accordance with the Prevention of Cruelty to Animals Act 1986 and under the guidelines of the National Health and Medical Research Council (NH&MRC) Code of Practice for the Care and Use of Animals for Experimental Purposes in Australia. Efforts were made to minimise animal suffering and the number of animals used.
Human inferior vagal ganglion
Punctate binding of [α33P]dATP was observed over sections of human inferior vagal ganglia (Fig. 1A). [α33P]dATP binding (188±16 DPM/mm2) was fully displaced by ATP (1 mM). There was no significant displacement of binding by NECA, PPADS, NF279 or UTP (Fig. 1B); however, α,βMeATP (Fig. 1C) and 2MeSATP (Fig. 1D) could partially displace [α33P]dATP binding (Table 1).
Rat nodose ganglia
Binding of [α33P]dATP was present on the rat nodose ganglia and the vagus nerve (Fig. 2A). Binding of [α33P]dATP (185±38 DPM/mm2) was
Discussion
The current study provides the first clear evidence of widespread P2Y1-IR receptor in the adult rat medulla oblongata; furthermore, this P2Y1-IR is also subject to bi-directional transport along the rat vagus nerve. In addition, observations from this study suggest the potential use of [α33P]dATP as a radioligand for P2Y receptor autoradiography. Taken together, our observations further extend the findings of previous autoradiographic studies, which identified a number of P2Y-like binding sites
Acknowledgements
These studies were supported in part by the National Health and Medical Research Council of Australia, of which A.J.L. is an R.D. Wright Fellow.
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