Intragranular colocalization of immunoreactive urotensin I and II in the urophysis of the carp, Cyprinus carpio

An immuno-electron microscopy revealed the presence of four types of nerve ending in the urophysis of the carp: those with immunoreactivity for both urotensin I (UI) and urotensin II (UII), those with immunoreactivity for either UI or UII, and those with immunoreactivity for neither. The intragranular colocalization of UI- and UII-specific immunoreactivities was observed in the nerve endings with immunoreactivity for both peptides