Expression of two-pore domain potassium channels in nonhuman primate sperm.
OBJECTIVE
Two-pore domain potassium channels (K(2P)) play integral roles in cell signaling pathways by modifying cell membrane resting potential. Here we describe the expression and function of K(2P) channels in nonhuman primate sperm.


METHODS
Experimental animal study, randomized blinded concentration-response experiments.


METHODS
University-affiliated primate research center.


METHODS
Male nonhuman primates.


METHODS
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 K(2P) agonist (docosahexaenoic acid) and antagonist (gadolinium).


METHODS
Semiquantitative protein expression and cellular localization and quantitative changes in specific kinematic parameters and acrosome integrity.


RESULTS
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.


CONCLUSIONS
The results demonstrated expression and function of K(2P) potassium channels in nonhuman primate sperm for the first time. The unique, discrete distributions of K(2P) channels in nonhuman primate sperm suggest specific roles for this subfamily of ion channels in primate sperm function.
Chow
Gregory E
GE
Washington National Primate Research Center, University of Washington, Seattle, Washington, USA.
Muller
Charles H
CH
Curnow
Eliza C
EC
Hayes
Eric S
ES
D000818:Animals; D002478:Cells, Cultured; D015870:Gene Expression / Q000502:physiology; D020869:Gene Expression Profiling; D006801:Humans; D008254:Macaca nemestrina; D008297:Male; D016062:Porosity; D015221:Potassium Channels / Q000378:metabolism*; D024683:Potassium Channels, Tandem Pore Domain / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D013094:Spermatozoa / Q000378:metabolism*; D014018:Tissue Distribution
C410295:KCNK5 protein, human; C503433:Kcnk4 protein, mouse; D015221:Potassium Channels; D024683:Potassium Channels, Tandem Pore Domain; C103742:potassium channel protein TREK-1