Three-Day-Old Human Unfertilized Oocytes after In Vitro Fertilization/Intracytoplasmic Sperm Injection Can Be Activated by Calcium Ionophore A23187 or Strontium Chloride and Develop to Blastocysts

Abstract

Our objective was to observe the effectiveness of the calcium ionophore A23187 or strontium chloride on the activation and subsequent embryonic development of 3-day-old human unfertilized oocytes after in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI). A total of 279 3-day-old unfertilized oocytes after IVF or ICSI were randomized to be activated by the calcium ionophore A23187 (n=138) or strontium chloride (n=141). The activated oocytes were cultured in vitro for 3-5 days. Activation rate, pronucleus formation, cleavage rate, and developmental potential of parthenotes during culture were evaluated. A total of 170 unfertilized oocytes were activated; 65 developed to cleavage stage, 19 developed to greater than the eight-cell stage, and five blastocysts were obtained. The activation rate of the calcium ionophore A23187 group was higher than that of the strontium chloride group (75.4% and 46.8%, respectively; p<0.05); there was significant difference between two groups (p<0.05). Among the 44 cleaved oocytes in the calcium ionophore A23187 group, eight developed to the two- to four-cell stage, 17 developed to the five- to eight-cell stage, 15 developed to greater than the eight-cell stage, and four blastocysts were obtained. Among the 21 cleaved oocytes in the strontium chloride group, six developed to the two- to four- cell stage, 10 developed to the five- to eight-cell stage, four developed to greater than the eight-cell stage, and one blastocyst was obtained. Three-day-old unfertilized human oocytes after IVF or ICSI could be activated by the calcium ionophore A23187 or strontium chloride, and a small part of parthenogenetic embryos developed into blastocysts. The treatment with the calcium ionophore A23187 was better than that of strontium chloride in respect to the activation rate of 3-day-old unfertilized human oocytes after IVF or ICSI.

The combination of calcium ionophore A23187 and GM-CSF can safely salvage aged human unfertilized oocytes after ICSI

“…In PIFF cases, different methods have been applied to achieve artificial oocyte activation (AOA): activation using an electric current [12][13][14], modifications of ICSI techniques [5,15], and the use of chemical agents, such as strontium chloride [16], puromycin [17], and Ca 2+ ionophores, with calcium ionophore A23187 being the most widely used [8,[18][19][20][21][22][23].…”

“…While there are several studies highlighting the value of calcium ionophore A23187 for AOA immediately after or within a short time post ICSI, there are only two studies on its use in salvaging aged human unfertilized oocytes, at either 20 h post ICSI (combination of A23187 and puromycin) [17] or 3 days post ICSI [16]. So far, only one live birth after activation of 1-day-old unfertilized oocytes with calcium ionophore A23187 has been reported [22].…”

Comparison of Human Oocyte Activation Between Round-Headed Sperm Injection Followed by Calcium Ionophore Treatment and Normal Sperm Injection in a Patient With Globozoospermia

“…Some other reagents and/or methods have been applied to achieve AOA, such as electric current (31,32), ethanol (33), strontium chloride (34), and puromycin (8). There are still very limited reports on comparison of different activation reagents on human oocyte activation and embryo development (8,31,34) but it appears that calcium ionophore has better efficiency than strontium chloride (34). Electric current can also activate human oocytes (31, 32) but it has not been applied in human IVF due to expensive cost of equipment.…”

Parthenogenesis and Human Assisted Reproduction

“…A recent study [ 21 ] compared the efficacy of SrCl 2 or Ca 2+ ionophore on the activation rates of 3-day-old FF human oocytes and observed that the treatment with the ionophore was more efficient in activating aged unfertilized oocytes and embryo development to the blastocyst stage. However, these reports on the activation of FF oocytes do not reflect the real parthenogenetic embryonic development potential of the human oocyte as the studies mentioned earlier [ 11 , 14 , 15 ], because, in these last instances, there is a high probability that a paternal genome is present in the ooplasm, considering that IVF or ICSI was previously performed.…”