Description:
Binding of [125I]Bolton‐Hunter labelled substance P (BH‐SP) and [125I]human α‐calcitonin gene‐related peptide (hαCGRP) to rat bladder tissue sections was characterized and the respective binding sites localized by light‐microscopic autoradiography. BH‐SP binding sites were localized to epithelium, blood vessels and smooth muscle while hCGRP binding sites were present only over the epithelium. These results suggest that the range of biological actions of substance P and calcitonin gene‐related peptide, which may be co‐released from the same afferent terminals, might be determined by the different distributions of their respective receptors.