Desensitization follows excitation of bladder primary afferents by intravesical capsaicin, as shown by c-fos activation in the rat spinal cord

• Type: Article in International Scientific Journal
• Date: 1996

Authors

Francisco Cruz (Author) FMUP; António Avelino Silva (Author) FMUP; Coimbra, A (Author) Other

Journal

Title: Pain

Vol. 64

Pages: 553-557

ISSN: 0304-3959

Publisher: Wolters Kluwer Health

Indexing

ISI Web of Knowledge - 30 Citations

Scopus - 33 Citations

Other information

Authenticus ID: P-001-EQ4

DOI: 10.1016/0304-3959(95)00157-3

Abstract (EN): Activation of the protooncogene c-fos at spinal cord segments T12-L2 and L5-S1 was used to study the effects of topical administration of capsaicin on bladder primary afferents coursing in the hypogastric (HGN) or pelvic (PN) nerves of adult rats. Two hours after capsaicin instillation in the bladder numerous Fos cells occurred in lamina I at T12-L2 and in lamina I, intermediolateral gray matter (ILG) and dorsal commissure (DCM) at L5-S1. Twenty-four hours later, the Fos immunoreaction had disappeared from the spinal cord. At this time, instillation of 1% acetic acid into the bladder of capsaicin-treated rats induced considerably fewer Fos cells than in animals that had been instilled only with the vehicle solution for capsaicin. The difference in the average number of Fos cells was statistically significant in lamina I, ILG and DCM at L5-S1 but not in lamina I at T12-L2. Thus, intravesical capsaicin at the doses used excites bladder primary afferents coursing in the HGN and PN, but only desensitizes those coursing in the PN. It is suggested that this may depend on the differential occurrence of capsaicin receptors in the two nerves.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 5