5-HT2 and 3 receptor antagonists suppress the response of rat type I slowly adapting mechanoreceptor: an in vitro study.
Previous experiments have shown an increase in rat type I mechanoreceptor responsiveness during arterial serotonin (5-hydroxytryptamine) infusion and the presence of serotonin immunostaining in Merkel cells. The current findings demonstrate that the 5-HT(2) antagonists ritanserin and ketanserin, as well as the 5-HT(3) antagonist MDL 72222, reduce type I response to a standardized mechanical stimulus in an in vitro skin preparation. In addition, ritanserin blocked the enhancement of type I response produced by 5-HT. These experiments suggest that serotonin is released during mechanical distortion of the Merkel cell membrane and alters action potential generation by the type I ending. In addition, it is possible that serotonin, released from outside the type I complex, influences mechanoreceptor responsiveness. For example, serotonin generated during inflammatory events could enhance type I response to mechanical stimulation and thereby increase symptoms of mechanical allodynia.
He
Liang
L
Department of Physiology, University of Utah School of Medicine, 410 Chipeta Way, Rm 156, Salt Lake City, UT 84108-1297, USA.
Tuckett
Robert P
RP
English
Kathleen B
KB
D000200:Action Potentials / Q000187:drug effects; D000222:Adaptation, Physiological; D000818:Animals; D005260:Female; D016166:Free Radical Scavengers / Q000494:pharmacology*; D007650:Ketanserin / Q000494:pharmacology; D008297:Male; D008465:Mechanoreceptors / Q000187:drug effects* / Q000502:physiology; D009924:Organ Culture Techniques; D010812:Physical Stimulation; D051381:Rats; D017207:Rats, Sprague-Dawley; D016713:Ritanserin / Q000494:pharmacology; D012701:Serotonin / Q000494:pharmacology*; D012702:Serotonin Antagonists / Q000494:pharmacology; D012867:Skin / Q000098:blood supply / Q000294:innervation; D014326:Tropanes / Q000494:pharmacology
D016166:Free Radical Scavengers; D012702:Serotonin Antagonists; D014326:Tropanes; D016713:Ritanserin; D012701:Serotonin; D007650:Ketanserin; C042253:bemesetron