| Full text | |
| Author(s): |
Lubaczeuski, C.
[1]
;
Balbo, S. L.
[1]
;
Ribeiro, R. A.
[2]
;
Vettorazzi, J. F.
[3]
;
Santos-Silva, J. C.
[3]
;
Carneiro, E. M.
[3]
;
Bonfleur, M. L.
[1]
Total Authors: 7
|
| Affiliation: | [1] Univ Estadual Oeste Parana, Ctr Ciencias Biol & Saude, Lab Fisiol Endocrina & Metab, Cascavel, PR - Brazil
[2] Univ Fed Rio de Janeiro, Macae, RJ - Brazil
[3] Univ Estadual Campinas, Inst Biol, Dept Biol Estrutural & Func, Lab Pancreas Endocrino & Metab, Campinas, SP - Brazil
Total Affiliations: 3
|
| Document type: | Journal article |
| Source: | Brazilian Journal of Medical and Biological Research; v. 48, n. 5, p. 447-457, MAY 2015. |
| Web of Science Citations: | 10 |
| Abstract | |
The parasympathetic nervous system is important for β-cell secretion and mass regulation. Here, we characterized involvement of the vagus nerve in pancreatic β-cell morphofunctional regulation and body nutrient homeostasis in 90-day-old monosodium glutamate (MSG)-obese rats. Male newborn Wistar rats received MSG (4 g/kg body weight) or saline [control (CTL) group] during the first 5 days of life. At 30 days of age, both groups of rats were submitted to sham-surgery (CTL and MSG groups) or subdiaphragmatic vagotomy (Cvag and Mvag groups). The 90-day-old MSG rats presented obesity, hyperinsulinemia, insulin resistance, and hypertriglyceridemia. Their pancreatic islets hypersecreted insulin in response to glucose but did not increase insulin release upon carbachol (Cch) stimulus, despite a higher intracellular Ca2+ mobilization. Furthermore, while the pancreas weight was 34% lower in MSG rats, no alteration in islet and β-cell mass was observed. However, in the MSG pancreas, increases of 51% and 55% were observed in the total islet and β-cell area/pancreas section, respectively. Also, the β-cell number per β-cell area was 19% higher in MSG rat pancreas than in CTL pancreas. Vagotomy prevented obesity, reducing 25% of body fat stores and ameliorated glucose homeostasis in Mvag rats. Mvag islets demonstrated partially reduced insulin secretion in response to 11.1 mM glucose and presented normalization of Cch-induced Ca2+ mobilization and insulin release. All morphometric parameters were similar among Mvag and CTL rat pancreases. Therefore, the higher insulin release in MSG rats was associated with greater β-cell/islet numbers and not due to hypertrophy. Vagotomy improved whole body nutrient homeostasis and endocrine pancreatic morphofunction in Mvag rats. (AU) | |
| FAPESP's process: | 11/09012-6 - Molecular mechanisms involved in the dysfunction and death of pancreatic beta cells in Diabetes Mellitus: strategies for the prevention of islet dysfunction and for islet mass recuperation in different cellular and animal models |
| Grantee: | Antonio Carlos Boschiero |
| Support Opportunities: | Research Projects - Thematic Grants |