ISSN:
1432-2013
Keywords:
Catecholamines Growth hormone High altitude Insulin Parathormone
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Abstract. The purpose of this study was to examine the effects of prolonged hypoxia on adipose tissue lipolysis, in relation to the weight loss usually observed at high altitude. Eight male subjects were exposed for 31 days to gradually increasing hypobaric hypoxia up to the equivalent altitude of 8848 m (Mt Everest) in a decompression chamber, after 7 days at 4350 m for altitude pre-acclimatization. A biopsy of subcutaneous adipose tissue was performed before and after hypoxic exposure, to study in vitro changes in adipose tissue sensitivity. Fat mass, adipocyte volume and spontaneous lipolysis were not impaired by the exposure to hypoxia. The in vitro lipolytic response to epinephrine, isoproterenol, growth hormone (GH) and parathormone (PTH) decreased significantly (P〈0.01, P〈0.05, P〈0.01 and P〈0.01 respectively), as did the plasma concentration of free fatty acid (P〈0.01). The anti-lipolytic effect promoted by α2-adrenergic receptor stimulation (epinephrine with propranolol) was greater after hypoxia (P〈0.05), while the anti-lipolytic activity of insulin was decreased (P〈0.01). In conclusion, prolonged exposure to hypobaric hypoxia led to a potent reduction in lipid mobilization, through a decrease in the efficiency of β-adrenergic, GH and PTH lipolytic pathways, as well as an increment in the α2-adrenergic-receptor-mediated anti-lipolytic effects.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/s004249900167
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