ANGIOTENSIN-II IMMUNOREACTIVITY IN THE VEGETATIVE REGIONS OF THE THORACIC AND SACRAL SPINAL-CORD OF GUINEA-PIG AND RAT

The localization of angiotensin-II immunoreactivity (Ang-II-IR) has been studied in the thoracic and sacral spinal cord vegetative regions of male and female guinea pigs and rats. Immunoreactivity is located in varicose nerve fibers and axon terminals throughout the studied areas. We have not observed any immuno-reactive neurons in these regions. The highest density of IR structures was observed in the thoracic and sacral vegetative networks of both studied species (GALABOV and DAVIDOFF, 1976; GALABOV, 1978). Addditionally IR fibers and terminals were found between the ependymocytes and in close contact with blood vessels. Slight immunostaining of the apical poles of the ependymocytes was observed too. These localizations of the IR fibers and terminals suggest that Ang II has important functional significance in the regulation of the vegetative activity, and plays some role in the local blood flow regulation. As to the origin of the Ang II-IR fibers and terminals most probably they are coming from higher levels of the central nervous system (brainstem and hypothalamus).