7 Provide a rationale for the use of A23187 in IVF in vitro

7) Provide a rationale for the use of A23187 in IVF (in vitro fertilization). Provide an example situation in which it would be necessary and better or worse than other methods that could induce capacitation.

Solution

A23187 is also known as Calcium ionophore. It is specially used in vitro fertilization process, where low fertilization rate is reported after the process of ICSI(Intracytoplasmic sperm injection). Calcium ionophore helps in oocyte activation after the process of ICSI has been carried out. Calcium ionophore has a respectable rate in oocyte activation. There are many other chemicals used for oocyte activation like ethanol,strontium chloride,puromycin,ionomycin etc. There are various artificial inducers like calcium ionophore,caffeine or heparin which are used for triggering acrosomal reactions,motility,hyperactivity that induce capacitation.

Let us study a situation where artificial inducer is necessary to induce capacitation.

We have collected samples of semen by artificial insemination of three mature male sheep. Divided fractions of the collective semen lying over one another under 1 ml of S-TALP(Tyrode\'s albumin lactate pyruvate) medium(one of the medium used in IVF) a part added to different concentrations of calcium ionophore(0.5, 0.75,1,1.55 mm/ml), heparin(10,25,50,75,100 meugram/ml) or caffeine(0.5,0.75,1,2 meugram/ml). Individual motility of sperms, their hyperactivity percentage and rate of acrosomal reactions were recorded after a time period of 0,1,2,3 and 4 hours after the incubation of treatments and control. They were also tested for the ability to fertilize sheep oocyte in vitro also. In this study the rate of penetration of oocytes inseminated with sperm treated with calcium ionophore and heparin was higher than caffeine. But the rate of fertilization was seemed to be higher with heparin with not much significant difference with others. So from this we conclude that calcium ionophore is equally good to induce capacitation as heparin and better than other capacitation inducers.