[Distribution and role of motilin receptor in the amygdala of rats].
OBJECTIVE
To explore the distribution and role of motilin receptor in the amygdala of rats.


METHODS
The distribution of motilin receptor in the amygdala was detected by immunohistochemistry in adult SD rats of either sex. The duodenal interdigestive migrating myoelectric complex (MMC) was recorded and analyzed for investigating the role of motilin receptor in the amygdala.


RESULTS
Motilin receptors were detected in the amygdala of rats. The medial amygdaloid nucleus contained the greatest amount of motilin receptors, which was also abound in the basolateral nucleus of the amygdala but less abundant in the basomedial nucleus of the amygdala, central amygdaloid nucleus and lateral amygdaloid nucleus. The binding of motilin receptors and motilin in the amygdala caused shortening of duodenal MMC cycle duration and increased amplitude and frequency of phase III. The effects were completely abolished by subdiaphragmal vagotomy but not by intravenous injection of atropine, phentolamine or propranolol. Anti-motilin serum partially abolished these effects, and destruction of the basolateral nucleus of the amygdala had no effects on duodenal MMC.


CONCLUSIONS
Motilin receptors are present in all the subnuclei of the amygdala. The effects of microinjection of motilin in the amygdala on duodenal MMC might rely on either the effects of noncholinergic and nonadrenergic neurons on the duodenal smooth muscle, or increase in local motilin via amygdala-hypothalamus-brain stem-vagus pathway, indicating the important role of motilin receptor in the amygdala in duodenal MMC regulation.
Liu
Mei
M
Department of Gastroenterology, Second Hospital of Xi'an Jiaotong University, Xi'an 710004, China. maybelake@126.com
Dong
Lei
L
Zhu
Wen-yi
WY
D000679:Amygdala / Q000378:metabolism* / Q000502:physiology; D000818:Animals; D004386:Duodenum / Q000502:physiology; D005260:Female; D008297:Male; D009037:Motilin / Q000008:administration & dosage*; D016065:Myoelectric Complex, Migrating; D051381:Rats; D017207:Rats, Sprague-Dawley; D011964:Receptors, Gastrointestinal Hormone / Q000378:metabolism* / Q000502:physiology; D018013:Receptors, Neuropeptide / Q000378:metabolism* / Q000502:physiology
D011964:Receptors, Gastrointestinal Hormone; D018013:Receptors, Neuropeptide; C050802:motilin receptor; D009037:Motilin