title: Glucagon-producing cells are increased in Mas-deficient mice.
abstract: It has been shown that angiotensin(1-7) (Ang(1-7)) produces several effects related to glucose homeostasis. In this study, we aimed to investigate the effects of genetic deletion of Ang(1-7), the GPCR Mas, on the glucagon-producing cells. C57BL6/N Mas-/-mice presented a significant and marked increase in pancreatic α-cells (number of cells: 146 ± 21 vs 67 ± 8 in WT; P < 0.001) and the percentage per islet (17.9 ± 0.91 vs 12.3 ± 0.9% in WT; P < 0.0001) with subsequent reduction of β-cells percentage (82.1 ± 0.91 vs 87.7 ± 0.9% in WT; P < 0.0001). Accordingly, glucagon plasma levels were increased (516.7 ± 36.35 vs 390.8 ± 56.45 pg/mL in WT; P < 0.05) and insulin plasma levels were decreased in C57BL6/N Mas-/-mice (0.25 ± 0.01 vs 0.31 ± 56.45 pg/mL in WT; P = 0.02). In order to eliminate the possibility of a background-related phenotype, we determined the number of glucagon-producing cells in FVB/N Mas-/-mice. In keeping with the observations in C57BL6/N Mas-/-mice, the number and percentage of pancreatic α-cells were also significantly increased in these mice (number of α-cells: 260 ± 22 vs 156 ± 12 in WT, P < 0.001; percentage per islet: 16 ± 0.8 vs 10 ± 0.5% in WT, P < 0.0001). These results suggest that Mas has a previously unexpected role on the pancreatic glucagon production.
authors.affiliation: Department of Physiology and BiophysicsNational Institute of Science and Technology in Nanobiopharmaceutics, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
authors.forename: Janaína
authors.initials: J
authors.lastname: Felix Braga
authors.affiliation: Cardiology Institute of Rio Grande do Sul/University Foundation of Cardiology (IC/FUC)Porto Alegre, Rio Grande do Sul, Brazil.
authors.forename: Daniela
authors.initials: D
authors.lastname: Ravizzoni Dartora
authors.affiliation: Max-Delbruck Center of Molecular Medicine (MDC)Berlin-Buch, Berlin, Germany.
authors.forename: Natalia
authors.initials: N
authors.lastname: Alenina
authors.affiliation: Cardiology Institute of Rio Grande do Sul/University Foundation of Cardiology (IC/FUC)Porto Alegre, Rio Grande do Sul, Brazil.
authors.forename: Michael
authors.initials: M
authors.lastname: Bader
authors.affiliation: Department of Physiology and BiophysicsNational Institute of Science and Technology in Nanobiopharmaceutics, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil robsonsant@gmail.com.|Cardiology Institute of Rio Grande do Sul/University Foundation of Cardiology (IC/FUC)Porto Alegre, Rio Grande do Sul, Brazil.
authors.forename: Robson Augusto Souza
authors.initials: RA
authors.lastname: Santos
keywords: diabetes; metabolism