健脾化湿颗粒对D-IBS模型大鼠脑-肠轴中CRF和CRFR1的影响

Influence of Jianpi Huashi granule on 5-HT, 5-HTR3, and 5-HTR4 expression in the brain of rats with diarrhea-predominant irritable bowel syndrome

AIM: To investigate the effect of Jianpi Huashi granule on 5-hydroxytryptamine (5-HT), 5-hydroxytryptamine receptor 3 (5-HTR3), and 5-HTR4 expression in the brain of rats with diarrhea-predominant irritable bowel syndrome (D-IBS) to evaluate their implications in the therapeutic effects of Jianpi Huashi granule in improving colonic motility and visceral sensitivity.

METHODS: A rat model of D-IBS was established by intragastric administration of Sennae decoction combined with restraint stress. Rats were divided into several groups. Jianpi Huashi granule was given to rats in Jianpi Huashi groups, Pinaverium bromide tablets to rats in the positive group and water to the other groups. ELISA was used to detect the content of 5-HT in the hippocampus. Immunohistochemistry assay was used to detect the expression of 5-HT, 5-HTR3, and 5-HTR4 in the prefrontal cortex, hippocampus, and hypothalamus. Reverse transcription-polymerase chain reaction (RT-PCR) was used to detect the mRNA expression of 5-HTR3 and 5-HTR4 in the hippocampus.

RESULTS: In the D-IBS model group, the content of 5-HT in the hippocampus (327.30 ± 22.35 vs 265.33 ± 13.60) and the expression of 5-HT in the prefrontal cortex, hippocampus, hypothalamus (0.16 ± 0.02 vs 0.08 ± 0.01, 0.19 ± 0.02 vs 0.09 ± 0.01, 0.17 ± 0.02 vs 0.08 ± 0.01, P < 0.01 for all) were increased significantly compared to the normal group. The expression of 5-HTR3 (0.29 ± 0.02 vs 0.10 ± 0.01, 0.23 ±0.02 vs 0.09 ± 0.01, 0.22 ± 0.02 vs 0.09 ± 0.02, P < 0.01 for all) and 5-HTR4 (0.25 ± 0.02 vs 0.11 ± 0.01, 0.28 ± 0.02 vs 0.10 ± 0.02, 0.27 ± 0.02 vs 0.11 ± 0.02, P < 0.01 for all) in the prefrontal cortex, hippocampus and hypothalamus, and the expression of 5-HTR3 and 5-HTR4 mRNAs (0.54 ± 0.01 vs 0.17 ± 0.05, 0.73 ± 0.08 vs 0.10 ± 0.02, P < 0.01 for all) in the hippocampus were significantly increased in the model group compared with the normal group. After treatment, the contents of 5-HT in the hippocampus in the positive control group, medium- and high-dose Jianpi Huashi granule groups were significantly decreased (298.92 ± 12.16, 286.29 ± 24.43, 279.86 ± 20.05 vs 327.30 ± 22.35, P < 0.05, P < 0.01), the expression of 5-HT in the prefrontal cortex in medium- and high-dose Jianpi Huashi granule groups was significantly reduced (0.12 ± 0.01, 0.11 ± 0.01 vs 0.16 ± 0.02, P < 0.01 for both), and the expression of 5-HT in the hippocampus and hypothalamus in the positive control group, medium- and high-dose Jianpi Huashi granule groups was significantly decreased. The expression of 5-HTR3 mRNA in the hippocampus in all treatment groups was significantly reduced.

CONCLUSION: Jianpi Huashi granule regulates colonic motility and visceral sensitivity in rats with D-IBS possibly by modulating the expression of 5-HT, 5-HTR3, and 5-HTR4 in the brain.