Abstract
Background: Obesity is strongly associated with female infertility, but the mechanisms underlying this relationship are largely unknown. Methods: We investigated the effect of increasing dietary fat percentage upon body mass, hypothalamic neuropeptide gene expression, adipose hormone secretion and fertility in females of the inbred mouse strains C57BL/6J and DBA/2J. To assess the effect of obesity independent of dietary influence, we also compared these parameters in wild-type female C57BL/6J mice to those congenic for the obesogenic mutations ob/ob and Ay/a. Results: After 24 weeks, rather than exhibiting an obese, leptin-resistant phenotype like their female DBA/2J counterparts, wild-type female C57BL/6J mice remained lean, fertile and manifested increased hypothalamic LEPR-B expression. Although both mutant genotypes were associated with obesity and subfertility, ob/ob mice demonstrated significantly increased hypothalamic LEPR-B expression, whereas Ay/a mice had a significant reduction. Interestingly, wild-type female C57BL/6J mice were noted to manifest significantly higher and lower levels of adiponectin and tissue plasminogen activator inhibitor-1 (tPAI-1), respectively, than weight-matched wild-type female DBA/2J mice. Conclusions: We conclude that (1) resistance to the obese-infertile phenotype in female C57BL/6J mice is associated with increased hypothalamic leptin receptor expression and alterations in adipokine levels consistent with decreased adipose tissue inflammation and (2) that long-standing hyperleptinemic obesity in mice is associated with a downregulation of the hypothalamic leptin receptor.
Original language | English (US) |
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Pages (from-to) | 395-402 |
Number of pages | 8 |
Journal | International Journal of Obesity |
Volume | 31 |
Issue number | 3 |
DOIs | |
State | Published - Mar 2007 |
Keywords
- Adiponectin
- DIO
- Infertility
- PAI-1
ASJC Scopus subject areas
- Medicine (miscellaneous)
- Endocrinology, Diabetes and Metabolism
- Nutrition and Dietetics