Cryopreservation affects osmotic tolerance and intracellular ion concentration through changes in expression levels of water and ion channels. Control of these changes is important for cell survival after cryopreservation. Relatively little is known about changes in K+ channel expression compared to water channel expression. This study was performed to investigate changes in TASK-2 channel (KCNK5: potassium channel, subfamily K, member 5), a member of two-pore domain K+ channel family, in cryopreserved mouse ovaries. Cryopreservation increased TASK-2 mRNA expression in mouse ovaries. In addition, TASK-2 protein expression was upregulated in vitrified and slowly frozen ovaries. TASK-2 protein was expressed in all area of granulosa cells that surround the oocyte within the follicle, except nucleus. Viability of cells overexpressed with TASK-2 was higher than that of vector-transfected cells. Our results found that TASK-2 expression was increased by cryopreservation and overexpression of TASK-2 decreased cryopreservation-induced cell death. These results suggest that TASK-2 upregulation might reduce cryodamage.

• Dawon Kang(Dept. of Physiology, College of Medicine and Institute of Health Sciences, Gyeongsang National University)
• Changyong Choe(Animal Genetic Resources Research Center, National Institute of Animal Science, RDA)
• Chang-Woon Kim(Dept. of Obstetrics and Gynecology, Samsung Changwon Hospital, Sungkyunkwan University School of Medicine)
• Ae Jin Goo(Dept. of Physiology, College of Medicine and Institute of Health Sciences, Gyeongsang National University)
• Jaehee Han(Dept. of Physiology, College of Medicine and Institute of Health Sciences, Gyeongsang National University)