Document Detail

Disturbance of the reproductive axis induced by negative energy balance.
MedLine Citation:
PMID:  9727594     Owner:  NLM     Status:  MEDLINE    
Animal reproduction is impaired when intake of energy is so restricted that activities essential to life are threatened; this is seen as a homeostatic adjustment that restricts wasteful energy expenditure. Fasting or exercising to a degree requiring considerable energy expenditure has major effects on the hypothalamus, including activation of corticotrophin-releasing factor (CRF) neurons, suppression of thyrotrophin-releasing hormone synthesis, and increased growth hormone secretion; these are associated with increased concentrations of hypothalamic neuropeptide Y mRNA and are corrected by administration of leptin, an adipose-tissue protein with a tertiary structure similar to the cytokine interleukin-2. This response to fasting results from a disordered pattern of activity in the gonadotrophin-releasing hormone (GnRH) pacemaker, characterized by reduced luteinizing hormone pulsatility, particularly during daytime. Animal studies have suggested that the response depends on an intact afferent vagal system from the stomach and the presence of oestrogen. Noradrenergic neurons forming the A2 group increase the activity of CRF neurons that, in turn, inhibit GnRH pulsatility. Reproductive impairment due to fasting is reversed by leptin, and abnormalities of leptin are described in individuals who fast or who develop exercise-induced amenorrhoea. This paper discusses these changes induced by negative energy balance and speculates on the involvement of leptin as a contributor to these abnormalities.
S J Judd
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Publication Detail:
Type:  Journal Article; Review    
Journal Detail:
Title:  Reproduction, fertility, and development     Volume:  10     ISSN:  1031-3613     ISO Abbreviation:  Reprod. Fertil. Dev.     Publication Date:  1998  
Date Detail:
Created Date:  1998-11-05     Completed Date:  1998-11-05     Revised Date:  2005-11-16    
Medline Journal Info:
Nlm Unique ID:  8907465     Medline TA:  Reprod Fertil Dev     Country:  AUSTRALIA    
Other Details:
Languages:  eng     Pagination:  65-72     Citation Subset:  IM    
Department of Medicine, Flinders Medical Centre, Bedford Park, SA, Australia.
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MeSH Terms
Adipose Tissue / metabolism
Energy Metabolism*
Food Deprivation
Hypothalamus / metabolism*,  physiology
Proteins / secretion
Reproduction / physiology
Reg. No./Substance:
0/Leptin; 0/Proteins

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