The female reproductive lifespan is determined by the pool of primordial follicles, ovarian structures containing immature eggs (oocytes) which periodically mature into cells which can be fertilized. While primordial follicles are gradually and physiologically lost with age, pathological conditions or exposure to environmental chemicals can accelerate their exhaustion leading to infertility.

According to Deepak Adhikari and colleagues, University of Gothenburg, Sweden, a solution to this problem consists of the immunosuppressant drug rapamycin (pictured). The researchers demonstrated that this compound, a lipophilic macrolide inactivating mTORC1, inhibits the exhaustion of the pool of primordial follicles occurring in mice upon phosphatidylinositide 3-kinase hyper-activation. Thus, rapamycin may be used in the clinic to protect female fertility from the detrimental effects of ovotoxic agents such as chemotherapeutic drugs.

• Pharmacological Inhibition of mTORC1 Prevents Over-Activation of the Primordial Follicle Pool in Response to Elevated PI3K Signaling,
  D. Adhikari, S. Risal, K. Liu, Y. Shen,
  PLoS ONE 2013, 8(1): e53810.
  DOI: 10.1371/journal.pone.0053810