Impact of toxicant exposures on ovarian gap junctions.

Ovarian gap junctions function to provide intercellular communication between ovarian cell types and are critical for proper ovarian function. Connexons are communication channels that are comprised of connexin (CX) proteins. Connexins can be regulated through endocrine signals, thus have dynamic expression throughout the estrous cycle. Not surprisingly, ovarian function is negatively affected in mouse models deficient in Cx genes; loss of Gja4 impairs folliculogenesis while ovaries devoid of Gja1 have reductions in oocyte growth. Chemicals that negatively affect ovarian function, termed ovotoxicants, can directly target Cx mRNA or protein abundance. Endocrine disrupting chemicals, medicinal drugs, pesticides, industrial chemicals, polycyclic aromatic hydrocarbons, recreational drugs and dietary components can affect Cx levels and/or function. Also, aging and obesity can impact ovarian Cx's. This review highlights what is currently known about ovotoxicant exposures that impact ovarian gap junction function as well as identifies the many gaps in our knowledge in this area of ovarian biology.