A novel surgical technique focused on the study of the ileum: The preduodenal ileal transposition.

AIMS: Our main goal is to study the effects on the carbohydrate metabolism. Thus, we designed various experimental surgical models on healthy non-obese Wistar rats to reproduce several conditions. In this sense, we report a new experimental model. It is well known that bariatric surgery has important effects on the control of Type 2 Diabetes Mellitus. The underlying reasons are yet unknown, although the different theories focused in the release of different hormones after the pass of the nutrients through the tract. These released hormones have opposite effects that come together in a balanced glycemic metabolism. MATERIALS AND METHODS: After bariatric surgical techniques, the modified anatomy resulted in an imbalance of the secreted hormones. Wistar rats were randomized in two groups Sham and surgical group. Our model consisted on the transposition of the terminal ileum right after the pylorus. Weight gain, food intake, and basal glycemia were measured weekly. RESULTS: We did not obtain significant differences between both groups for these functional variables. CONCLUSIONS: This technique involved an early pass of the bolus through the ileum. The change on the luminal pH, along with the lack of enzymes to absorb the content, or the changes in the release of several hormones must be variables to the study. The mortality rate was assumable considering it was an experimental model on animals.

OBJETIVO: Crear un nuevo modelo quirúrgico experimental en ratas Wistar sanas no obesas para estudiar los efectos del metabolismo glucídico. Es bien sabido que las técnicas de cirugía bariátrica tienen un efecto importante sobre la resolución de la diabetes mellitus tipo 2. Se han invocado diferentes hipótesis, algunas centradas en el papel que tienen distintas hormonas secretadas por el propio tubo digestivo tras el paso de los nutrientes a su través, pero las razones últimas subyacentes permanecen desconocidas. El efecto contrapuesto de dichas hormonas consigue un efecto de control glucémico. El desequilibrio hormonal tras las alteraciones anatómicas de las cirugías bariátricas podría estar en la base de dicha mejora del metabolismo glucídico final. MATERIAL Y MÉTODOS: Las ratas fueron operadas en dos grupos (control quirúrgico y experimental) y se procedió a disponerles el íleon anastomosado al antro pilórico, previo al esfínter pilórico. Medimos distintos parámetros funcionales (ganancia de peso, ingesta y glucemias semanales). RESULTADOS: No obtuvimos diferencias significativas en la evolución de estos parámetros. CONCLUSIONES: Este modelo será útil para nuestro propósito de estudiar el íleon, en su componente secretor de enterohormonas, cuando el paso de los nutrientes se produzca tempranamente. La mortalidad fue asumible, dada la innovación técnica realizada.

A surgical study about jejunum: the exclusion to nutrients flow. A novel strategical technique

The bariatric surgery techniques applied in patients with obesity have reported a great ability to improve Type 2 Diabetes mellitus (T2DM). Some published data report an increasing betacell mass in some surgical processes. This mechanism was specially seen in the bariatric surgeries which affect the length of the small bowel. The intrinsic mechanism that links both phenomena seemed to be related to the enterohormonal secretion pattern. Many enteral hormones have been invoked as the effector of these mechanisms. Previous reports focused on the medial portion of jejunum, as the precise place in which some particular enterohormones determine the homeostatic glycemic improvement. Goto-Kakizaki diabetic male rats underwent surgery to exclude the 50% medial jejunum from the normal nutrients flow. This medial portion of jejunum was not resected, but anastomosed by both extremes to the abdominal wall, and a stoma was performed. This surgery wasnamed as Medial Jejunal Exclusion (MJE). We studied the functional parameters in a three-month survival period. In this sense basal glycaemia, weight increase and food intake were not modified between the surgical and control groups. The study presented a mortality of the 24%. This model was designed for the late study of serum and enterohormones release in this jejunal portion, excluded of nutrients flow. We report a new surgical technique, which appears to balance the homeostatic processes in order to maintain the survival of diabetic rats. Thus, this mechanism could be in the basis of T2DM improvement, and this novel surgical model will help study this precise portion of jejunum

No disponible

The main participation of the enterohormone GLP-1 after bariatric surgery.

BACKGROUND: Numerous hypotheses are called to explain the beneficial effect on glucose metabolism after bariatric surgery. Some authors advocate for the secretion and release of various substances with endocrine functions for the explanation on this event. One of the substances most marked as effector, with contrasting effects but controversial data, is GLP-1. METHODS: Our study was performed in healthy male Wistar rats, to avoid the absence of confounding factors such as T2DM and obesity. In order to know the adaptation of GLP-1 secretion after surgery 5 groups were designated: two control groups (fasting and surgical stress), and three surgical groups (gastric sleeve, 50% resection of the midgut and the Roux en Y gastric bypass). After three months the GLP-1 synthesis in the different portions of the small intestine and the expression of the membrane receptors in pancreatic islet cells were studied by immunohistochemical techniques. RESULTS: There was a significant increase in the number of secretory cells in ileum, duodenum and jejunum in mixed (RYGB) and malabsorptive (RI50) surgical groups. An elevation of pancreatic receptors signal was also observed in the same techniques versus controls. CONCLUSIONS: Our data indicate that intestinal secretion of GLP-1 and its sensitivity to the pancreatic changes were increased like a response of an adaptive effect to the mechanical aggression of the digestive tube and as alteration of nutrient flow after surgery.

La controvertida participación del GLP-1 en los mecanismos fisiológicos desencadenados tras cirugía bariátrica / The controversial participation of GLP-1 in the physiological mechanisms unchained after bariatric surgery

RESUMEN: Numerosas hipótesis se invocan para explicar el efecto beneficioso sobre el metabolismo glucídico tras la cirugía bariátrica. Algunos autores abogan por la secreción y liberación de distintas sustancias con funciones endocrinas (enterohormonas). Una de las sustancias más señaladas como efector, con efectos contrastados pero datos controvertidos, es el GLP-1. Nuestro estudio se realizó en ratas Wistar macho sanas, para evitar la ausencia de factores de confusión como son la DMT2 y la obesidad. Para conocer el mapa de adaptación a la secreción de GLP-1 tras la cirugía, se designaron 5 grupos: dos grupos control (de ayuno y de estrés quirúrgico); y tres grupos quirúrgicos (gastrectomía vertical, resección del 50 % del intestino medio y el Bypass gástrico con montaje en Y de Roux). Después de tres meses se estudiaron mediante técnicas inmunohistoquímicas el patrón de síntesis de GLP-1 en las distintas porciones del intestino delgado. También se estudió la expresión de los receptores de membrana en las células de los islotes pancreáticos. Se observó la existencia de un significativo aumento del número de células secretoras en íleon, duodeno y yeyuno en los grupos quirúrgicos de técnicas mixtas (RYGB) y malabsortivas (RI50). Igualmente se observó una elevación de los receptores pancreáticos en las mismas técnicas frente a los controles. Nuestros datos indican que la secreción intestinal de GLP-1 y su sensibilidad a nivel pancreáticas están aumentada, como efecto adaptativo a la agresión mecánica del tubo y a la alteración del flujo de nutrientes tras la cirugía.

SUMMARY: Numerous hypotheses are invoked to explain the beneficial effect on glucose metabolism after bariatric surgery. Some authors advocate for the secretion and release of various substances with endocrine functions (enterohormones). One of the substances most marked as effector, with contrasting effects but controversial data, is Glucagon-like peptide-1 GLP-1. Our study was performed in healthy male Wistar rats, to avoid the absence of confounding factors such as DMT2 and obesity. In order to know the map of adaptation to GLP-1 secretion after surgery, five groups were designated: Two control groups (fasting and surgical stress); and three surgical groups (vertical sleeve gastrectomy, 50 % midgut resection and Roux-en-Y gastric bypass). After three months, the GLP-1 synthesis pattern was studied by immunohistochemical techniques in the different portions of the small digestive tract. The expression of membrane receptors in pancreatic islet cells was also studied. There was a significant increase in the number of secretory cells in ileum, duodenum and jejunum in mixed surgical (RYGB) and malabsorptive (RI50) groups. An elevation of pancreatic receptors was also observed in the same techniques against controls. Our data indicated that intestinal secretion of GLP1 and its sensitivity to the pancreatic level were increased, both to an adaptive effect to the mechanical aggression of the digestive tube and to the alteration of nutrient flow after surgery.