Assisted yes, but where do we draw the line?
In a recent report in Reproductive Biomedicine Online by Ebner et al., a comprehensive multi-centre study was presented on the use of a calcium ionophore, A23187, to artificially activate oocytes from patients who had poor fertilization rates in previous cycles. Under physiological conditions, the calcium increase in oocytes at activation is caused by influx and release from specific stores and ion channels, and has precise temporal, quantitative and spatial patterns. Calcium ionophores may release Ca(2+) in an uncontrolled fashion from intracellular stores that would not normally be involved in the activation process. Ionophores, including A23187, have a multitude of effects on cell homeostasis, not yet defined in oocytes, that may have long-term effects, for example on gene expression. We suspect that the successful births reported by Ebner et al. are a result of the overriding influence of the injected spermatozoa, rather than the effect of the ionophore; nevertheless, such an invasive non-physiological approach to assisted reproduction techniques is worrying, especially as epigenetic effects may result in future generations.
Stazione Zoologica Anton Dohrn, Naples, Italy.
Luigia
L
Santella
Centre for Assisted Fertilization, Naples, Italy. Electronic address: brian.dale@virgilio.it.
Brian
B
Dale
D000001:Calcimycin / Q000009:adverse effects / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism; D061207:Calcium Ionophores / Q000009:adverse effects / Q000494:pharmacology; D005260:Female; D006801:Humans; D059471:In Vitro Oocyte Maturation Techniques / Q000379:methods; D008297:Male; D009865:Oocytes / Q000187:drug effects / Q000378:metabolism; D011247:Pregnancy; D027724:Reproductive Techniques, Assisted / Q000009:adverse effects; D020554:Sperm Injections, Intracytoplasmic
D061207:Calcium Ionophores; D000001:Calcimycin; D002118:Calcium
calcium increases; caution; ionophore; oocyte activation