GABA triggers mammalian sperm acrosome reaction (AR). Here, evidence is presented, showing that rat spermatozoa contain GABAA receptors, composed of α5, β1 and β3 subunits. The effects of GABAA receptor agonist and antagonist on the induction of AR in rat spermatozoa were assessed using the chlortetracycline assay. Muscimol, a GABAA receptor agonist, triggered AR; whereas bicuculline, a GABAA receptor antagonist and picrotoxin, a GABAA receptor/Cl- channel blocker, inhibited the ability of GABA or progesterone to induce AR. In conclusion, GABAA receptors appear to mediate the action of progesterone in inducing AR in rat spermatozoa.
- Acrosome reaction
- Chlortetracycline assay
- Receptor agonist and antagonist
ASJC Scopus subject areas
- Cellular and Molecular Neuroscience