Universidad de Murcia. Departamento de Biología Celular e Histología
Abstract
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 cellularit