AMPK: a link between metabolism and reproduction?

5'AMP-activated protein kinase (AMPK) is a serine/threonine kinase that acts as a fuel gauge in regulating energy metabolism. It restores cellular ATP levels by switching on catabolic pathways and switching off anabolic pathways. Some evidence indicates that AMPK could be also implicated in reproductive functions such as granulosa cell steroido- genesis and nuclear oocyte maturation in several species. Some metabolic hormones such as leptin resistin adiponectin (three adipokines) and ghrelin may in part act through the AMPK signaling. These hormones are also involved in the control of the reproductive functions at the hypothalamus-pituitary-gonadal axis level in both male and female. Thus, AMPK could be one of the signaling pathways controlling the interactions between energy balance and reproduction. The reproductive system is tightly coupled with energy balance, and thereby metabolic abnormalities can lead to the development of some physiopotho logical situations such as the polycystic ovary syndrome (PCOS) Women with PCOS show altered fertility mostly associated with metabolic disorders such as insulino-resistance hyperinsulinemia and/or dyslipidemia. Metformin, On insulin -sensitizer, is used for the treatment of women with PCOS. It restores subnormal fertility and energy balance. Recent studies show that AMPK is involved in the mechanism of action Of metformin. Thus, it may be a therapeutic target. However, further investigations are necessary to elucidate the functions of AMPK in both metabolic and reproductive tissues.