Cholinergic nerve terminals in the ventrolateral medullary pressor area: pharmacological evidence

摘要: Abstract This investigation was designed to demonstrate the presence of cholinergic nerve terminals in pressor area ventrolateral medulla (VLPA) and study effects release endogenous acetylcholine this area. Bilateral microinjections (0.1–2 nmol)/site) 3,4-diaminopyridine (DAP), which releases from terminals, into VLPA anesthetized rats evoked an increase blood pressure heart rate lasted for 20–40 min. Intravenous injections same doses agent failed evoke a response. The ganglion blocker, chlorisondamine (3 mg/kg, i.v.) abolished responses DAP indicating that were mediated by sympathetic nervous system. Microinjections scopolamine or specific M2 muscarinic receptor antagonist (AFDX-116) prevented tachycardic subsequent at sites via receptors. hemicholinium nmol/site; impairs synthesis) attenuated sites. These results indicate substance released may be predominantly evokes origin physiological significance these are not known.