Proposed mechanisms by which PPARs may impact ovarian function and female fertility. The flow chart illustrates the potential interactions between the activation of PPARs and various factors known to impact processes critical for normal ovarian function. See text for details. Stimulatory impact is indicated by a (+). The ability to both stimulate and/or inhibit is denoted by (+/-). COX-2 = cyclooxygenase 2; ET-1 = endothelin -1; LDL = low density lipoprotein; MMPs = matrix metalloproteinases; NOS = nitric oxide synthase; NSAIDs = non-steroidal anti-inflammatory drugs; PAI-1 = plasminogen activator inhibitor -1; VEGF = vascular endothelial growth factor. Asterisk (*) denotes reported targets of PPARs in the ovary.