Substance P microinjections into the nucleus tractus solitarius elicit a pressor response in capsaicin-treated rats.
The role of Substance P in the nucleus tractus solitarius was investigated by observing the effect of local injections of the peptide on blood pressure, heart rate and vasopressin secretion in both normal and neonatally capsaicin-treated rats. Substance P did not modify and of these parameters in control rats, but elicited a marked pressor response, not associated with changes in heart rate or plasma vasopressin levels, in capsaicin-treated animals. The study demonstrates that neonatal capsaicin treatment modifies the sensitivity of this area of the brainstem to exogenous substance P and provides evidence for a modulatory action of substance P on the cardiovascular system at the site of the nucleus tractus solitarius.
D000344:Afferent Pathways / Q000187:drug effects; D000818:Animals; D001127:Arginine Vasopressin / Q000097:blood; D001794:Blood Pressure / Q000187:drug effects*; D002211:Capsaicin / Q000494:pharmacology*; D002319:Cardiovascular System / Q000294:innervation; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D008297:Male; D008526:Medulla Oblongata / Q000187:drug effects*; D009410:Nerve Degeneration / Q000187:drug effects; D011311:Pressoreceptors / Q000187:drug effects; D051381:Rats; D011919:Rats, Inbred Strains; D013116:Spinal Cord / Q000187:drug effects; D013373:Substance P / Q000494:pharmacology*
D001127:Arginine Vasopressin; D013373:Substance P; D002211:Capsaicin