cycloheximide + ionomycin

Cycloheximide + ionomycin is a pharmacological combination used for artificial oocyte activation (AOA) in patients experiencing repeated fertilization failure after intracytoplasmic sperm injection (ICSI). Ionomycin, a polyether calcium ionophore, facilitates the influx of extracellular calcium and the release of intracellular calcium stores, mimicking the calcium oscillations normally triggered by sperm-borne phospholipase C zeta (PLCζ). Cycloheximide is a glutarimide antibiotic that acts as a potent protein synthesis inhibitor by binding to the 60S ribosomal subunit. In the context of AOA, cycloheximide prevents the synthesis of cyclin B, leading to the inactivation of maturation-promoting factor (MPF) and the subsequent exit of the oocyte from metaphase II. This dual approach addresses both the initiation of calcium signaling and the downstream cell cycle progression required for successful fertilization. The protocol has been extensively studied and utilized by the Reproductive Medicine Center at Tongji Hospital.

Other names

Ionomycin/CHXAOA protocolArtificial Oocyte Activation protocol