Colokinetic effect of somatostatin in the spinal defecation center in rats
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Somatostatin and its receptors are expressed in the spinal cord, but the functional roles of the peptide remain unknown. In this study, we examined the colokinetic effect of somatostatin in the spinal defecation center in anesthetized rats. Intrathecal application of somatostatin into the lumbo-sacral cord caused propulsive contractions of the colorectum. However, somatostatin administered intravenously or intrathecally to the thoracic cord failed to enhance colorectal motility. Transection of the thoracic cord had no significant impact on the colokinetic action of somatostatin. The enhancement of colorectal motility by intrathecal administration of somatostatin was abolished by severing the pelvic nerves. Our results demonstrate that somatostatin acting on the spinal defecation center causes propulsive motility of the colorectum in rats. Considering that somatostatin is involved in nociceptive signal transmission in the spinal cord, our results provide a rational explanation for the concurrent appearance of chronic abdominal pain and colonic motility disorders in IBS patients.
KeywordsAutonomic nervous system Blood pressure GI motility Irritable bowel syndrome Large intestine SRIF
Compliance with ethical standards
This research was supported in part by Grants-in-Aid for Scientific Research (KAKENHI) from the Ministry of Education, Culture, Sports, Science, and Technology of Japan (JP26292164). This research was also supported in part by Grant-in-Aid for JSPS Research Fellow (JP16J03278). KN was supported by Research Fellowships for Young Scientists from the Japan Society for the Promotion of Science. The authors declare no competing financial interests.
Conflict of interest
The authors declare that they have no conflict of interest.
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