IBR   13079
INSTITUTO DE BIOLOGIA MOLECULAR Y CELULAR DE ROSARIO
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
A FLUORIMETRIC POPULATION ASSAY SHOWS THAT MEMBRANE POTENTIAL OF HUMAN SPERM DEPEND ON PKA A
Autor/es:
CAROLINA BARO GRAF; CARLA RITAGLIATI; LIS PUGA MOLINA; MARIANO G BUFFONE; CINTIA V STIVAL; DARIO KRAPF
Lugar:
CORDOBA
Reunión:
Congreso; 52th Annual Meeting Argentine Society for Biochemistry and Molecular Biology; 2016
Resumen:
Physiological changes that endow mammalian sperm with fertilizing capacity are known as sperm capacitation, which involves, among other events, changes in ion membrane-permeability. This ion permeability changes impact on the plasma membrane potential (Em) of any animal cell, which is typically negatively charged inside. Em hyperpolarization associated to capacitation is well described for mouse sperm, where it depends on potassium fluxes and it is both necessary and sufficient for sperm to undergo the acrosome reaction. However, little is known in human sperm, where mostly qualitative flow cytometry analyses have been conducted. Our results show for the first time a set up for measuring human sperm membrane potential, by means of the cationic carbocyanineDiSC(3)5 in a fluorimetric population assay. The equilibrium potential for potassium was for each sperm sample calculated using the Nernst equation and considering an intracellular human sperm potassium concentration of 120 mM. Our results show a high variation of absolute values among different samples donors. However, hyperpolarization of Em was consistently observed, regardless of the initial non-capacitated Em value. This hyperpolarization is, as in the case of mouse sperm, dependent on PKA activity. Our experimental conditions have the potential to add a strong diagnostic tool to reproductive clinic.