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Changes in the Muscarinic Receptors on the Colonic Smooth Muscles of Rats with Spinal Cord Injury

OBJECTIVE: To investigate changes in (1) the colonic response to acetylcholine (Ach), (2) the muscarinic (M) receptors in the colon, and (3) the levels of colonic contraction-related proteins after a spinal cord injury (SCI). METHOD: We divided 16 Sprague-Dawley rats into 2 groups: the control group...

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Detalles Bibliográficos
Autores principales: Joo, Min Cheol, Kim, Yong Sung, Choi, Eul Sik, Oh, Jung Taek, Park, Hyun Joon, Lee, Moon Young
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Korean Academy of Rehabilitation Medicine 2011
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3309258/
https://www.ncbi.nlm.nih.gov/pubmed/22506180
http://dx.doi.org/10.5535/arm.2011.35.5.589
Descripción
Sumario:OBJECTIVE: To investigate changes in (1) the colonic response to acetylcholine (Ach), (2) the muscarinic (M) receptors in the colon, and (3) the levels of colonic contraction-related proteins after a spinal cord injury (SCI). METHOD: We divided 16 Sprague-Dawley rats into 2 groups: the control group and the SCI group. A spinal cord transection was performed surgically at the T10 vertebral level. After 1 week, the entire colon was divided into 2 segments, the proximal and distal colon. Each segment was mounted in a longitudinal or circular muscle direction in a 10-ml organ bath. We determined the intergroup differences as percentage changes in contractility after Ach treatment alone, Ach treatment with M2 receptor antagonist (AQ-RA741) pretreatment, and Ach treatment with M3 receptor antagonist (4-DAMP) pretreatment. Western blot analyses were performed to determine the expression level of RhoA, and heat shock protein 27 (HSP27). RESULTS: Compared to the control rats, the SCI rats showed an increased response to Ach along both the directions in the proximal colon (p<0.05). Compared to the control group, in the SCI group, the Ach response was significantly different in the proximal segment under AQ-RA741 pretreatment (p<0.05) and in the distal segment under 4-DAMP pretreatment (p<0.05). Findings of the western blot analyses showed a significant decrease in the level of protein gene product 9.5 in the proximal and distal colon and a significant increase in the level of RhoA and HSP27 in the proximal colon of the SCI rats. CONCLUSION: Our results suggest that changes in colonic contractility after SCI are partly attributable to changes in the M receptor subtypes.