Menopause: The Journal of The North American Menopause Society
Vol. 20, No. 12, pp. 1264/1274
DOI: 10.1097/gme.0b013e31828f5e3c
* 2013 by The North American Menopause Society
Adverse association between obesity and menopause in mice
treated with bezafibrate, a pan peroxisome proliferatorYactivated
receptor agonist
Tatiane da Silva Faria, BSc, PhD, Antonio Ludgero Correia-Junior, BSc, MSc,
Thabata Lessa dos Anjos, MD, Marcia Barbosa Aguila, RD, PhD,
and Carlos Alberto Mandarim-de-Lacerda, MD, PhD
Abstract
Objective: The goal of this study was to investigate the combined effects of ovariectomy (OVX) and high-fat
diet (HF) on insulin sensitivity and pancreatic remodeling in C57BL/6 mice treated with bezafibrate.
Methods: Female C57BL/6 mice were subjected to OVX or surgical procedure without removal of the ovary
(SHAM). Animals received standard chow (SC; 10% lipids) or HF (60% lipids). After 13 weeks on the diets, the
animals were subdivided into six groups based on diet, bezafibrate treatment, or both: SHAM-SC, SHAM-HF,
SHAM-HFBz, OVX-SC, OVX-HF, and OVX-HFBz. After treatment for 5 weeks, the pancreas was removed and
analyzed using morphometry, stereological tools, immunostaining, and multiplex assay kits.
Results: SHAM-HF and OVX-HF mice showed increased fasting glucose levels, plasma insulin levels, ho-
meostasis model of assessment for insulin resistance index, body mass, islet hypertrophy, A-cell mass, and insulin
immunostaining, but decreased GLUT2 immunostaining. Bezafibrate treatment prevented islet hypertrophy and
reduced body mass, plasma insulin levels, and homeostasis model of assessment for insulin resistance index.
Conclusions: OVX combined with HF accentuates the effects of menopause, leading to the development of
insulin resistance. Bezafibrate treatment reduces body mass, plasma insulin levels, and pancreatic islet hypertrophy
in mice fed HF.
Key Words: Ovariectomy Y High-fat diet Y Insulin resistance Y Islet hypertrophy Y GLUT2.
O
besity, a serious public health problem in the 21st
century, leads to fatty infiltration and organ dys-
function of the heart, kidney, and liver.
1
More re-
cently, a similar condition has been shown to occur in the
pancreas in the form of nonalcoholic fatty pancreas disease.
2<4
This condition is significant because visceral obesity is as-
sociated with many diseases, particularly hypertension, hy-
perlipidemia, impaired glucose tolerance, pancreatic A-cell
failure, and insulin resistance (IR).
5,6
As a consequence, in
women with type II diabetes mellitus (T2DM) and in rodent
models of diabetes and obesity, A-cells compensate for IR by
increasing their mass before failure.
7
Menopause is a transition period characterized by a pro-
gressive reduction of estrogens levels, which is associated
with increased visceral adiposity, IR, T2DM, cardiovascular
disease (CVD), and inflammatory markers.
8<10
Today, women
can expect to spend nearly a third of their lives in the meno-
pausal state. Therefore, the individual and public health im-
pact of menopause-associated diseases is significant.
11
One
approach to modeling menopause in rodents is ovariectomy
(OVX; surgically induced menopause), which promotes obe-
sity and metabolic complications, particularly IR.
12
Peroxisome proliferatorYactivated receptors (PPARs) are
members of the nuclear hormone receptor superfamily.
PPAR>, PPARC/ss, and PPARF are ligand-activated nuclear
transcription factors that modulate the expression of genes
regulating glucose, lipid, and cholesterol metabolism; an
imbalance in these factors can lead to obesity, T2DM, and
CVD. These receptors are also drug targets; currently,
PPAR> (fibrates) and PPARF (thiazolidinediones) agonists
are used clinically for the treatment of dyslipidemia and
T2DM, respectively.
13
Bezafibrate is a known activator of
PPARs that can activate PPAR subtypes and is considered a
pan-PPAR agonist.
14
Received December 5, 2012; revised and accepted February 26, 2013.
From the Laboratory of Morphometry, Metabolism, and Cardiovascular
Disease, Biomedical Center, Institute of Biology, State University of Rio
de Janeiro, Rio de Janeiro, Brazil.
Funding/support: This study was supported by Conselho Nacional de
Desenvolvimento Cientifico e Tecnologico (www.cnpq.br) and Fundacao
de Amparo a Pesquisa do Estado do Rio de Janeiro (www.faperj.br).
Financial disclosure/conflicts of interest: None reported.
Address correspondence to: Carlos Alberto Mandarim-de-Lacerda, MD,
PhD, Laboratorio de Morfometria, Metabolismo e Doen0a Cardiovascular,
Centro Biomedico, Instituto de Biologia, Universidade do Estado do Rio
de Janeiro, Av. 28 de Setembro, 87, fds, Rio de Janeiro 20551-030, RJ,
Brazil. E-mail: mandarim@uerj.br
1264 Menopause, Vol. 20, No. 12, 2013
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