Figure 5.

In situ hybridization showing localization of P2Y₂ receptor mRNA transcripts in hamster proximal urethra. (a) Overview of P2Y₂ receptor mRNA expression. (b) Negative control competing labelled probe for P2Y₂ receptors with an excess of unlabelled probe, abolishing the staining shown in (a). (c) P2Y₂ receptor mRNA is expressed on the longitudinal and circular smooth muscle layer just beneath the epithelium. (d) Expression at higher magnification of P2Y₂ mRNA on the circular and longitudinal smooth muscle layer in phase contrast. Scale bars: (a, b) 160 μm; (c) 40 μm and (d) 20 μm. Double arrows: longitudinal smooth muscle; single arrows: circular smooth muscle and arrowheads: epithelium.