RESUMEN
AIM: Ghrelin can act as a signal for meal initiation and play a role in the regulation of gastrointestinal (GI) motility via hypothalamic circuit. This study investigated the correlation between changes of hypothalamic ghrelin system and GI motility dysfunction and anorexia in rats with chronic renal failure (CRF). METHODS: Sprague-Dawley (SD) rats (male/female 1:1, 180 ± 20 g) were randomly classified into a CRF group and control group (n = 8 per group). 5/6 nephrectomy was used to construct the CRF model. When plasma creatinine concentration (PCr) and blood urea nitrogen (BUN) in the CRF group were twice higher than the normal, food intake (g/24 h) and gastrointestinal interdigestive myoelectric complex (IMC) were detected. Then all rats were killed for assessment of the mRNA expression of ghrelin and growth hormone secretagogue receptor (GHS-R) in hypothalamus using reverse transcription-polymerase chain reaction. Analysis of variance, Student-Newman-Keuls-q-test and Correlation Analysis were used to do statistical analysis. P < 0.05 was considered as statistically significant. RESULTS: Compared to the control group, the CRF group was obviously decreased in the food intake (g/24 h), the phase III duration and amplitude and the ghrelin and GHS-R expression in the hypothalamus (P < 0.05). There was a positive correlation between them (P < 0.05). CONCLUSION: Changes of ghrelin and GHS-R in the hypothalamus correlate with gastrointestinal motility dysfunction and anorexia in rats with CRF.
Asunto(s)
Anorexia/etiología , Enfermedades Gastrointestinales/etiología , Motilidad Gastrointestinal , Ghrelina/metabolismo , Hipotálamo/metabolismo , Fallo Renal Crónico/complicaciones , Uremia/etiología , Animales , Anorexia/genética , Anorexia/metabolismo , Anorexia/fisiopatología , Biomarcadores/sangre , Nitrógeno de la Urea Sanguínea , Creatinina/sangre , Modelos Animales de Enfermedad , Ingestión de Alimentos , Femenino , Enfermedades Gastrointestinales/genética , Enfermedades Gastrointestinales/metabolismo , Enfermedades Gastrointestinales/fisiopatología , Ghrelina/genética , Hipotálamo/fisiopatología , Fallo Renal Crónico/genética , Fallo Renal Crónico/metabolismo , Fallo Renal Crónico/fisiopatología , Masculino , Complejo Mioeléctrico Migratorio , ARN Mensajero/metabolismo , Ratas , Ratas Sprague-Dawley , Receptores de Ghrelina/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Factores de Tiempo , Uremia/genética , Uremia/metabolismo , Uremia/fisiopatologíaRESUMEN
BACKGROUND/AIMS: Ghrelin plays a central role in the regulation of gastrointestinal (GI) motility. This study aimed to investigate the expression of ghrelin and growth hormone secretagogue receptor (GHSR) in the central nervous system of rats with chronic renal failure (CRF). METHODS: Sprague-Dawley rats (male, 180 ± 20 g, n = 24) were treated by 5/6 nephrectomy to construct CRF model. As their plasma creatinine concentration and blood urea nitrogen were maintained more than double the normal level for 2 weeks, they were killed for assessing the expression of ghrelin and GHSR in hypothalamus and hippocampus using immunohistochemistry and real-time polymerase chain reaction (RT-PCR). The rats (male, 180 ± 20 g, n = 24) treated by Sham operation served as a control. One-way analysis of variance and Student-Newman-Keuls q test were used to analyze group difference and a p-value of <0.05 was considered as statistically significant. RESULTS: Compared with the controls, the ghrelin and GHSR expression was obviously increased in the hippocampus (p < 0.05) but decreased in the hypothalamus of rats with CRF (p < 0.05). CONCLUSIONS: CRF was found to impact the expression of ghrelin and GHSR in hypothalamus and hippocampus. This might be associated with the CRF-induced GI motility dysfunction.