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Short‐term fasting promotes insulin expression in rat hypothalamus
Author(s) -
Dakic Tamara B.,
Jevdjovic Tanja V.,
Peric Mina I.,
Bjelobaba Ivana M.,
Markelic Milica B.,
Milutinovic Bojana S.,
Lakic Iva V.,
Jasnic Nebojsa I.,
Djordjevic Jelena D.,
Vujovic Predrag Z.
Publication year - 2017
Publication title -
european journal of neuroscience
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.346
H-Index - 206
eISSN - 1460-9568
pISSN - 0953-816X
DOI - 10.1111/ejn.13607
Subject(s) - medicine , insulin , endocrinology , hypothalamus , energy homeostasis , radioimmunoassay , western blot , biology , homeostasis , glucose homeostasis , insulin resistance , obesity , gene , biochemistry
In the hypothalamus, insulin takes on many roles involved in energy homoeostasis. Therefore, the aim of this study was to examine hypothalamic insulin expression during the initial phase of the metabolic response to fasting. Hypothalamic insulin content was assessed by both radioimmunoassay and Western blot. The relative expression of insulin mRNA was examined by qPCR . Immunofluorescence and immunohistochemistry were used to determine the distribution of insulin immunopositivity in the hypothalamus. After 6‐h fasting, both glucose and insulin levels were decreased in serum but not in the cerebrospinal fluid. Our study showed for the first time that, while the concentration of circulating glucose and insulin decreased, both insulin mRNA expression and insulin content in the hypothalamic parenchyma were increased after short‐term fasting. Increased insulin immunopositivity was detected specifically in the neurons of the hypothalamic periventricular nucleus and in the ependymal cells of fasting animals. These novel findings point to the complexity of mechanisms regulating insulin expression in the CNS in general and in the hypothalamus in particular.