Expression of two-pore domain potassium channels in nonhuman primate sperm

ObjectiveTwo-pore domain potassium channels (K2P) play integral roles in cell signaling pathways by modifying cell membrane resting potential. Here we describe the expression and function of K2P channels in nonhuman primate sperm.DesignExperimental animal study, randomized blinded concentration-response experiments.SettingUniversity-affiliated primate research center.Animal(s)Male nonhuman primates.Intervention(s)Western blot and immunofluorescent analysis of epididymal sperm samples. Kinematic measures (curvilinear velocity and lateral head displacement) and acrosome status were studied in epididymal sperm samples exposed to K2P agonist (docosahexaenoic acid) and antagonist (gadolinium).Main Outcome Measure(s)Semiquantitative protein expression and cellular localization and quantitative changes in specific kinematic parameters and acrosome integrity.Result(s)Molecular analysis demonstrated expression and specific regional distribution of TRAAK, TREK-1, and TASK-2 in nonhuman primate sperm. Docosahexaenoic acid produced a concentration-dependent increase in curvilinear velocity (P<.0001) with concomitant concentration-dependent reductions in lateral head displacement (P=.005). Gadolinium reduced velocity measures (P<.01) without significantly affecting lateral head displacement.Conclusion(s)The results demonstrated expression and function of K2P potassium channels in nonhuman primate sperm for the first time. The unique, discrete distributions of K2P channels in nonhuman primate sperm suggest specific roles for this subfamily of ion channels in primate sperm function.