Activation of 5-HT2 receptors inhibits the evoked release of [3H]noradrenaline in the rat spinal cord.
1. The participation of 5-HT2 receptors in the modulation of the evoked release of [3H]noradrenaline from rat spinal cord slices has been examined. 2. In rat spinal cord slices preincubated with [3H]noradrenaline, the alpha 2-receptor agonist clonidine (10(-6) mol/l) decreased the release of tritium evoked by field stimulation (600 pulses at 5 Hz, 20 mA, 2 msec), while the alpha 2-antagonist yohimbine (10(-6) mol/l) increased it. 3. The 5-HT2/5-HT1c agonist DOI (3 x 10(-7) mol/l) decreased the evoked release of tritium, an effect which was prevented by ketanserin (10(-7) mol/l). 4. It is suggested that in addition to presynaptic alpha 2-adrenoceptors, there are 5-HT2 receptors which modulate the release of noradrenaline in the rat spinal cord.
Celuch
S M
SM
Instituto de Investigaciones Farmacológicas, CONICET, Buenos Aires, Argentina.
Ramirez
A J
AJ
Enero
M A
MA
D000662:Amphetamines / Q000494:pharmacology; D000818:Animals; D003000:Clonidine / Q000494:pharmacology; D004558:Electric Stimulation; D005260:Female; D006213:Hallucinogens / Q000494:pharmacology; D066298:In Vitro Techniques; D007650:Ketanserin / Q000494:pharmacology; D009638:Norepinephrine / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D011942:Receptors, Adrenergic, alpha / Q000187:drug effects / Q000378:metabolism; D017366:Serotonin Receptor Agonists / Q000494:pharmacology*; D013116:Spinal Cord / Q000187:drug effects / Q000378:metabolism*; D015016:Yohimbine / Q000494:pharmacology
D000662:Amphetamines; D006213:Hallucinogens; D011942:Receptors, Adrenergic, alpha; D017366:Serotonin Receptor Agonists; D015016:Yohimbine; D007650:Ketanserin; D003000:Clonidine; C015952:4-iodo-2,5-dimethoxyphenylisopropylamine; D009638:Norepinephrine