Muscarinic and 5-HT4 receptors participate in the regulation of the frequency of spontaneous contractions of the longitudinal muscle in rat distal colon.
Spontaneous contractions of the intestine are thought to play an important role in the gastrointestinal motility, including peristalsis. In the present study, we investigated mechanisms for regulation of the frequency of spontaneous contractions, using longitudinal muscle strips in rat distal colon. Atropine significantly decreased the frequency of spontaneous contractions, indicating that neuromuscular transmission via muscarinic receptors increases the frequency of spontaneous contractions. SB-204070, 5-HT4 receptor antagonist also significantly decreased the frequency of spontaneous contractions, indicating that the activation of 5-HT4 receptors also increases the frequency of spontaneous contractions. In conclusion, it is suggested that muscarinic and 5-HT4 receptors participate in the regulation of the frequency of spontaneous contractions in the longitudinal muscle in rat distal colon, and that the frequency of spontaneous contraction is controlled by the enteric neurons.
Ono
Shigeyuki
S
Laboratory of Physiology, Graduate School of Nutritional and Environmental Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka, 422-8526, Japan.
Mitsui
Retsu
R
Karaki
Shin-ichiro
S
Kuwahara
Atsukazu
A
D000818:Animals; D001285:Atropine / Q000494:pharmacology; D003106:Colon / Q000502:physiology*; D004146:Dioxanes / Q000494:pharmacology; D005769:Gastrointestinal Motility / Q000187:drug effects / Q000502:physiology*; D008297:Male; D018727:Muscarinic Antagonists / Q000494:pharmacology; D009119:Muscle Contraction / Q000187:drug effects / Q000502:physiology*; D009130:Muscle, Smooth / Q000502:physiology*; D009924:Organ Culture Techniques; D010880:Piperidines / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D011976:Receptors, Muscarinic / Q000378:metabolism*; D044422:Receptors, Serotonin, 5-HT4 / Q000378:metabolism*; D058832:Serotonin 5-HT4 Receptor Antagonists; D012702:Serotonin Antagonists / Q000494:pharmacology
D004146:Dioxanes; D018727:Muscarinic Antagonists; D010880:Piperidines; D011976:Receptors, Muscarinic; D058832:Serotonin 5-HT4 Receptor Antagonists; D012702:Serotonin Antagonists; C084858:SB 204070A; D044422:Receptors, Serotonin, 5-HT4; D001285:Atropine