Browsing by Subject "Cellular differentiation"

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    Beta-cell mass adaptation to ileum nutrient flow. An experimental model
    (Universidad de Murcia. Departamento de Biología Celular e Histología, 2023) Salas Alvarez, Jesús; Campos Martínez, Francisco Javier; Camacho Ramírez, Alonso; Montero Peña, Cristian; Ribelles García, Antonio; Pérez Arana, Gonzalo M.; Prada Oliveira, J. Arturo
    The population with obesity has increased at an alarming rate during this century. Bariatric surgery has been demonstrated to be a good method to control weight and, most importantly, associated comorbidities, such as type 2 diabetes mellitus or high blood pressure. The reason why this happens even before losing significant weight remains unclear. Many authors believe that incretins play a main role, triggering special functions of the digestive tract. In reports, these hypotheses are known as foregut and hindgut theories. Initially, the theories were mutually exclusive; additionally, many other propositions have been analysed, according to different surgical techniques (e.g., bile acids and specific enterohormonal components). To elucidate the participation of the ileum, we developed a surgical technique to study the rapid response to nutrients in the ileum. Our goal was to study the stress functional test and histological changes in the pancreas that may explain the variations in glycaemic homeostasis in our rat model. After the oral glucose tolerance test, the experimental group presented an increased insulin release response with conserved glycaemia. We report an increasing beta-cell mass in the experimental group (+11.87 mg vs. +9.65 mg, respectively), while alpha-cell mass was not different. Based on transcription factors, the pathways that were increased were the proliferation process (as the number of PCNA-positive cells in the experimental group versus sham (+12.06 vs. +6.2 PCNA+ cells/mm2)) and transdifferentiation (ARX; +2.67 ARX+ cells/mm2 in the experimental group vs. +2.04 ARX+ cells/mm2 in the controls). We report the consequences of the rapid arrival of nonprocessed nutrients to the ileum on the endocrine cellular pancreas. The ileum could be a principal effector in the enterohormonal axis, which conditions endocrine pancreas cellularity
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    Effects of preduodenal ileal surgical transposition on enteroendocrine intestinal cells in wistar rats: Histomorphological and serum changes
    (Universidad de Murcia, Departamento de Biologia Celular e Histiologia, 2025) Campos Martínez, Francisco Javier; Salas Alvarez, Jesús; Falckenheiner Soria, Joshua; Murube Algarra, Carmen; Camacho Ramírez, Alonso; Visiedo García, Francisco Manuel; Prada Oliveira, J. Arturo; Pérez Arana, Gonzalo M.; Ribelles García, Antonio
    In our study, we focused on the role of the distal ileum as a main endocrine actor in relation to the pancreas. We investigated the effects of intestinally released hormones on the pancreas in terms of type 2 diabetes mellitus (T2DM) improvement, as a main effect of bariatric surgeries. To specifically study the importance of the ileum, we used an experimental surgical model performed in healthy Wistar rats. After preduodenal transposition of the ileum, we analyzed the histology and enterohormonal cells of the intestine. We measured the plasma level of several hormones and effectors in this enteropancreatic axis. We used a surgical control (Sham) group and a surgical group, where ileum preduodenal transposition (PDIT) was performed. We measured basal glycemia and serum levels of several incretins, including GLP-1, PYY, and GIP, and we performed a glucose overdose test. After two test periods, the basal glycemia and glucose overdose results were not different between groups, however, the PDIT group had significantly increased expression of GLP-1, with increased cellular release in the ileum and duodenum compared with the Sham group. Both plasma GIP levels and GIP tissue expression were decreased in the PDIT group compared with the sham group. There were no differences in PPY hormone levels. The ileum crypts and villi of the PDIT group showed improvement in histological parameters. We concluded that model animals had an altered transposed ileum related to the enterohormonal adaptation of the ileum. Our results indicated that the ileum is important in the hormonal control of the enteropancreatic axis.