A new prostaglandin E receptor mediates calcium influx and acrosome reaction in human spermatozoa.

ABSTRACT: Zona pellucida protein 3, a protein of the egg's extracellular matrix, and progesterone secreted by granulosa cells surrounding the oocyte are regarded as physiological stimuli of sperm acrosome reaction. Signal transduction steps initiated by both stimuli result in influx of Ca2+ from the extracellular space. Herein, we propose a role for prostaglandin (PG) E as a physiological inducer of Ca2+ influx and acrosome reaction in human spermatozoa. PGE1 specifically binds to human sperm membranes (Kd = 20.4 nM; Bmax = 88 fmol/mg protein) and induces a pertussis toxin-insensitive, transient increase in intracellular Ca2+ concentrations, which can be blocked by microM concentrations of La3+, Gd3+, and Zn2+. The kinetic profile was similar to that observed after progesterone challenge. Sequential

SUBMITTER: Schaefer M 

PROVIDER: S-EPMC19685 | biostudies-literature | 1998 Mar

REPOSITORIES: biostudies-literature