Contribution of peripheral opioid receptors to the trimebutine-induced contractions of the proximal colon in anesthetized rats.
In this study we investigated the involvement of opioid receptors in the contractile response to trimebutine using with the proximal colon of anesthetized rats. Trimebutine (3 mg/kg i.v.) enhanced spontaneous contractions of the proximal colon in anesthetized rats. The contractile response was partially inhibited by intravenous administration of an opioid antagonist, naloxone at 1 approximately 30 micrograms/kg, but was hardly depressed by intracisternal administration of naloxone (30 micrograms/kg). Morphine (30 micrograms/kg i.v.) evoked colonic contractions which were abolished by intravenous naloxone (30 micrograms/kg). These results suggest that the colonic contractions evoked by trimebutine in anesthetized rats are, in part, mediated by peripheral opioid receptors.
Nagasaki
M
M
Biological Research Laboratory, Tanabe Seiyaku Co., Ltd., Saitama, Japan.
Yamada
K
K
Ikezawa
K
K
Tamaki
H
H
D000758:Anesthesia; D000818:Animals; D001565:Benzoates / Q000494:pharmacology*; D003106:Colon / Q000187:drug effects; D008297:Male; D009020:Morphine / Q000494:pharmacology; D009119:Muscle Contraction / Q000187:drug effects*; D009130:Muscle, Smooth / Q000187:drug effects*; D009270:Naloxone / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D011957:Receptors, Opioid / Q000502:physiology*; D014287:Trimebutine / Q000494:pharmacology*
D001565:Benzoates; D011957:Receptors, Opioid; D009270:Naloxone; D009020:Morphine; D014287:Trimebutine