Altered leptin secretion in hyperinsulinemic mice under hypoxic conditions

Oestreicher, Iris and Meissner, Udo and Plank, Christian and Allabauer, Ida and Castrop, Hayo and Rascher, Wolfgang and Doetsch, Joerg (2009) Altered leptin secretion in hyperinsulinemic mice under hypoxic conditions. REGULATORY PEPTIDES, 153 (1-3). pp. 25-29. ISSN 0167-0115, 1873-1686

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Abstract

Objective: Hypoxia and insulin are known key players in the activation leptin transcription and translation in vivo and in vitro. These insulin- and hypoxia-dependent effects are leptin transcription are mediated via independent elements on the leptin-promotor, even more coincubation of the two stimuli in vitro results in a supraadditive effect on leptin transcription. The aim of this study was to examine whether hyperinsulinemia is able to interfere with the hypoxia-driven expression of leptin in adipose and extra-adipose tissue in vivo. Research methods and procedures: We used the KK/HlJ mouse strain as a model for hyperinsulinemia and C57BL/6J mice as control. These two groups were exposed to hypoxia for 12 h. Serum levels of insulin and leptin were analyzed by ELISA, mRNA expression of leptin was measured via real-time PCR. Results: In the hyperinsulinemic KK/HlJ mice, hypoxia was not able to further increase the amount of leptin in serum. Instead, a significant decrease of insulin levels was detected, while serum leptin and insulin levels increased in C57BL/6J. Analysis of leptin mRNA expression in subcutaneous fat, mesenteric fat and kidney revealed that hypoxia induces leptin transcription in kidneys of C57/BL6 but not in hyperinsulinemic animals. In contrast, leptin expression in adipose tissue was not increased during hypoxia. Discussion: We conclude that leptin regulation during hypoxia in vivo depends at least in part on the modulating role of insulin. The hypoxia driven induction of insulin expression in C57/BL6 animals may be responsible for the stimulation of leptin transcription. In contrast, already hyperinsulinernic animals showed no induction - neither of insulin nor leptin after short-term hypoxia. (C) 2008 Elsevier B.V. All rights reserved.

Item Type: Article
Uncontrolled Keywords: DIABETIC OB/OB MICE; GENE-EXPRESSION; SERUM LEPTIN; ADIPOSE-TISSUE; INDUCIBLE FACTOR-1; METABOLIC SYNDROME; INSULIN-SECRETION; HYPOBARIC HYPOXIA; RAT ADIPOCYTES; MESSENGER-RNA; Leptin; Insulin; Adipose tissue; Diabetes
Subjects: 500 Science > 570 Life sciences
Divisions: Biology, Preclinical Medicine > Institut für Physiologie > Prof. Dr. Wolf Hayo Castrop
Depositing User: Dr. Gernot Deinzer
Date Deposited: 05 Oct 2020 09:15
Last Modified: 05 Oct 2020 09:15
URI: https://pred.uni-regensburg.de/id/eprint/29459

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