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Chronic Administration of Glucocorticoids Directly Upregulates Prepro‐Neuropeptide Y and Y 1 ‐Receptor mRNA Levels in the Arcuate Nucleus of the Rat
Author(s) -
Larsen Philip J.,
Jessop David S.,
Chowdrey Hardial S.,
Lightman Stafford L.,
Mikkelsen Jens D.
Publication year - 1994
Publication title -
journal of neuroendocrinology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.062
H-Index - 116
eISSN - 1365-2826
pISSN - 0953-8194
DOI - 10.1111/j.1365-2826.1994.tb00566.x
Subject(s) - medicine , endocrinology , arcuate nucleus , neuropeptide y receptor , corticosterone , glucocorticoid receptor , in situ hybridization , biology , glucocorticoid , receptor , neuropeptide , hypothalamus , chemistry , messenger rna , hormone , biochemistry , gene
The complete sequence of the cDNA encoding the neuropeptide Y (NPY) Y 1 ‐receptor has recently been deduced from a rat brain library, and the presence of messenger ribonucleic acid (mRNA) encoding Y 1 ‐receptor protein has been demonstrated within the brain. Using quantitative in situ hybridization histochemistry, the content and distribution of Y 1 receptor and preproNPY mRNAs have been investigated in the hypothalamic arcuate nucleus of adrenalectomized rats receiving glucocorticoid replacement therapy for 12 days by means of either high doses of dexamethasone in their drinking water or by subcutaneous corticosterone pellets. Basal metabolic parameters such as weight gain or loss, blood glucose and plasma insulin were monitored: Dexamethasone treatment induced weight loss and a state of hyperinsulinemia with normoglycemia, while corticosterone treated animals displayed metabolic parameters identical to sham ADX animals. Within the arcuate nucleus of glucocorticoid treated animals, levels of Y 1 receptor and preproNPY mRNAs were increased. In contrast, adrenalectomy itself had no effect upon Y 1 ‐receptor mRNA levels or preproNPY mRNA levels in the arcuate nucleus. These studies demonstrate that glucocorticoids exert a stimulatory action on levels of Y 1 ‐receptor mRNA and preproNPY mRNA levels in the hypothalamic arcuate nucleus. This is the first evidence to suggest that the expression of a neuropeptide‐receptor gene in the central nervous system may be directly sensitive to peripheral hormonal signals.