Topographic variations in alpha-adrenergic and cholinergic response in the pig renal pelvis

The effect of alpha-adrenergic and cholinergic receptor stimulation is quantitatively analyzed in different regions of the pig pyeloureter. Smooth muscle strips from minor calyces, pelvis proper and ureter were investigated. Stimulation with potassium (127 mM) was used as reference. Both phenylephrine and carbachol caused a concentration-dependent increase in basal tone in the pelvis and the minor calyx. The maximum response obtained was significantly smaller in the pelvis than in the minor calyx. As compared to phenylephrine, the response to carbachol was negligible. The ureter showed a different behavior as compared to the minor calyx and pelvis. A constant basal tone could not be obtained and the tissue did not respond to potassium in a reproducible way.