Reproduction Abstracts

CatSper channels are expressed specifically in the principal piece of the sperm flagellum. In human sperm Catsper channel activation is polymodal and sensitive to increased pHi, progesterone and other agonists, potentially resulting in synergistic enhancement of Ca2+ influx and hyperactivation (1) We have investigated if the interaction of pHi with the CatSper agonist progesterone and 4-aminopyridine (4AP), a potent activator of hyperactivation in human sperm. [Ca<s...

Catsper is a Ca2+ permeable ion channel in the principal piece of the sperm flagellum that is crucial in regulation of motility. It is multimodally sensitive, being activated by voltage, pHi and diverse agonists including progesterone. Elevation of pHi and progesterone both shift voltage-sensitivity of the channel to more negative potentials and thus may act synergistically to enhance Ca2+-influx.1 However, intracellular alkalinisation of human...