Victor Pham: Dear viewers, my name is Victor and I'll be presenting characterization of alpha and beta-adrenergic and muscarinic receptor expression in porcine ureters. Pharmacological dilation of the ureter may facilitate retrograde intrarenal surgery. Swine are important for pharmacological testing due to their similar anatomy to humans. However, the swine ureter receptor distribution has not been fully characterized. As such, we characterize the adrenergic and muscarinic receptor distribution along the entire length of the swine ureter, as well as the renal pelvis and bladder cuff regions.

Four freshly excised ureters from four female juvenile Yorkshire swine were segmented into the renal pelvis, bladder cuff, proximal ureter, mid ureter, and distal ureter. Immunofluorescent staining with rabbit and goat anti-rabbit antibodies of the urothelium and smooth muscle of each segment was performed for alpha 1A, 1B, 1D, beta 1, 2, 3, muscarinic 1, 2, 3, 4, and 5. Relative immunoreactivity (RI) was calculated based on the pixel count per area of the tissue using ImageJ software. Data were analyzed with the Kruskal-Wallis test.

We found that there were no regional differences among alpha-beta, muscarinic III, and muscarinic five subtypes in the ureteral urothelium. Muscarinic 1 receptors in the distal ureter and bladder cuff urothelium were higher than the proximal ureter. Muscarinic 2 receptors were higher in the renal pelvis urothelium than in the urothelium of the proximal and middle ureter. Muscarinic 4 receptors were absent from all regions. Muscarinic 3 receptors were the only receptors found in the smooth muscle. They were also present in the ureteral urothelium. To conclude, all alpha and beta receptors were expressed uniformly along the entire porcine ureter. Swine ureters have regional differences regarding muscarinic 1 and 2 receptors, and lack muscarinic 4 receptors. Lastly, muscarinic 3 receptors were the only receptors found in the ureteral smooth muscle. Thank you.