[Effects of serotonin and norepinephrine on neuronal discharges of the nucleus tractus solitarii in medullary slices].
Effects of serotonin (5-HT) and norepinephrine (NE) on neuronal activities of the nucleus tractus solitarii (NTS) were investigated in rat medullary slice preparations. The spontaneous discharges after perfusion of slices with 5-HT (1 mumol.L-1, 3 min) were increased in 25 (58.1%), reduced in 13 (30.2%), and unchanged in 5 (11.7%) neurons. Afer perfusion of slices with NE (1 mumol.L-1, 3 min), the spontaneous discharges were reduced or ceased in 27 (62.8%), increased in 13 (30.2%), and unchanged in 3 (7.0%) neurons. Responding to both 5-HT and NE were 38 (88.4%) neurons, among which 21 were selected for studying the effect of ketanserin (a new 5-HT2 blocker). The spontaneous discharges were more increased in 10 (47.6%) and reduced in 4 (19.0%) neurons after perfusion of ketanserin+NE than after perfusion of NE alone. These results indicate that there is an interaction between 5-HT2 receptor and alpha 2 adrenoceptor at NTS level, suggesting that the central action of ketanserin may be one of its antihypertensive mechanisms.
Yang
J
J
Department of Pharmacology, Second Military Medical University, Shanghai, China.
Bao
J
J
Su
D F
DF
D000818:Animals; D004594:Electrophysiology; D005260:Female; D007650:Ketanserin / Q000494:pharmacology; D008297:Male; D008526:Medulla Oblongata / Q000187:drug effects / Q000502:physiology*; D009474:Neurons / Q000187:drug effects / Q000502:physiology; D009638:Norepinephrine / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D012701:Serotonin / Q000494:pharmacology*
D012701:Serotonin; D007650:Ketanserin; D009638:Norepinephrine