Possible involvement of descending serotonergic systems in antinociception by centrally administered elcatonin in mice.
To elucidate the mechanisms of analgesic action of elcatonin, a synthetic analog of eel calcitonin, the effect of centrally injected elcatonin on acetic acid-induced writhing behavior was examined in mice. Intracisternal or intracerebroventricular injection of elcatonin significantly inhibited acetic acid-induced writhing behavior, while the intrathecal injection of elcatonin did not inhibit it. The inhibitory effect of intracisternal elcatonin was significantly attenuated by subcutaneous pretreatment with methysergide and (+/-)-propranolol or by intrathecal pretreatment with methysergide, (+/-)-propranolol, 1-(2-methoxyphenyl)-4-[4-(2-phthalimido) butyl]-piperazine hydrobromide (NAN-190) and granisetron, but not with (+/-)-atenolol or butoxamine. Further, the depletion of spinal 5-hydroxytryptamine (5-HT, serotonin) by pretreatment with 5,7-dihydroxytryptamine (5,7-DHT) significantly attenuated the inhibitory effect of intracisternally injected elcatonin on acetic acid-induced writhing behavior. These results suggest that the inhibitory descending serotonergic systems may be involved, through 5-HT1A and 5-HT3 receptors, in the production of an antinociceptive effect by centrally injected elcatonin.
Nakamoto
H
H
Department of Molecular Pharmacology, Faculty of Pharmaceutical Sciences, Kyoto University, Japan.
Soeda
Y
Y
Seki
T
T
Watanabe
T
T
Satoh
M
M
D015116:5,7-Dihydroxytryptamine / Q000494:pharmacology / Q000627:therapeutic use; D019342:Acetic Acid; D000700:Analgesics / Q000494:pharmacology / Q000627:therapeutic use*; D000704:Analysis of Variance; D000818:Animals; D002116:Calcitonin / Q000031:analogs & derivatives* / Q000494:pharmacology / Q000627:therapeutic use; D008297:Male; D051379:Mice; D011596:Psychomotor Disorders / Q000139:chemically induced / Q000517:prevention & control; D011985:Receptors, Serotonin / Q000187:drug effects / Q000378:metabolism*; D018490:Serotonin Agents / Q000494:pharmacology / Q000627:therapeutic use
D000700:Analgesics; D011985:Receptors, Serotonin; D018490:Serotonin Agents; D015116:5,7-Dihydroxytryptamine; D002116:Calcitonin; D019342:Acetic Acid; C012755:elcatonin