Calcitonin Gene-Related Peptide Receptor Blocker Inhibits Spontaneous Activity of Human Ureter.

Calcitonin gene-related peptide (CGRP) is present in nerve fibers that innervate the human ureter and may have important influence on the motility of this organ. The aim of our study was to investigate whether CGRP could affect the motility of an isolated human ureter. The tension and intraluminal pressure of the isolated ureteral segments were recorded and registered on a personal computer. Both phasic and tonic contractions of the isolated preparations were measured as area under the tension or pressure recordings. CGRP and CGRP fragment 8-37 were separately added to the organ baths in a cumulative way, thereby gradually increasing their concentration in the baths' solution. Alpha-CGRP did not affect either phasic, spontaneous activity or tone of isolated ureteral segments, as measured by both tension and intraluminal pressure. On the other hand, CGRP 8-37 caused concentration-dependent inhibition of spontaneous contractions of the isolated ureteral segments.