Progesterone accelerates the onset of capacitation in mouse sperm via T-type calcium channels.

This study was undertaken to evaluate whether progesterone induces capacitation of mouse spermatozoa. When sperm were evaluated by chlortetracycline staining, addition of progesterone significantly increased the proportion of spermatozoa exhibiting the B pattern at 60 minutes of incubation, compared with that before incubation (23 +/- 6.2% vs. 13 +/- 2.9%, p < 0.01) and that in hTF medium without progesterone (23 +/- 6.2% vs. 13 +/- 4.2%, p < 0.01). If the redistribution of proteins in sperm plasma membrane such as protein binding calcium ion were defined as capacitation, it could be said that progesterone promoted capacitation of mouse sperm. This progesterone-induced capacitation was prevented by depletion of extracellular calcium ion and addition of NiCl2, a T-type calcium channel blocker, although thapsigargin, an inhibitor of Ca2+-ATPase, did not increase the number of capacitated sperm (B pattern; progesterone vs. progesterone + depletion of calcium ion, 18 +/- 3.5% vs. 8 +/- 2.5%, p < 0.05, progesterone vs. progesterone + NiCl2, 20 +/- 3.8% vs. 6 +/- 5.2%, p < 01). Furthermore, genistein, a protein tyrosine phosphorylation inhibitor, inhibited progesterone-induced capacitation (B pattern; progesterone vs. progesterone + genistein, 20 +/- 3.8% vs. 11 +/- 2.4%, p < 01). In conclusion, progesterone induces capacitation in mouse sperm and this capacitation may be associated with calcium influx and tyrosine phosphorylation.

Semen analysis and antisperm antibody.

Evaluation of the fertilizing potential of sperm is an important procedure in in vitro fertilization and embryo transfer (IVF-ET) clinic, in order to avoid performing invalid conventional IVF-ET or unnecessary intracytoplasmic sperm injection (ICSI). However, none of the standard semen parameters are reliable indices in predicting IVF outcome. The test examining sperm-zona interaction is the best present method, though the short supply of the human zona component should be solved. IVF-ET treatment is useful for pregnancy in women having sperm immobilizing antibodies because it avoids exposing sperms to antibodies that block fertilization. ICSI should be used in immunologically infertile men diagnosed by specific method to demonstrate the in vivo exposure of sperms to antisperm autoantibodies that block fertilization.

Avoidance of oocyte retrieval on the weekend through the use of scheduled ovarian hyperstimulation for in vitro fertilization and embryo transfer.

OBJECTIVE: To avoid oocyte retrieval for IVF-ET during the weekend, the scheduled method of ovarian hyperstimulation, in which oocyte retrieval is planned in advance for Monday through Wednesday, was evaluated. DESIGN: A retrospective study. SETTING: The IVF-ET unit of the Department of Obstetrics and Gynecology at Tokushima University Hospital. PATIENT(S): One hundred seventy-eight cycles in patients undergoing ovarian hyperstimulation for IVF-ET were stimulated according to the scheduled method of ovarian hyperstimulation (scheduled group). One hundred seventy-one cycles in patients of similar age and with comparable causes of infertility were stimulated according to the conventional method of ovarian hyperstimulation for IVF-ET (conventional group). INTERVENTION(S): In the scheduled method, under GnRH-a, the day of oocyte retrieval was determined in advance for IVF-ET. Ovarian stimulation with FSH and hMG was started 12 days before oocyte retrieval. MAIN OUTCOME MEASURE(S): The cancellation and clinical pregnancy rates (PRs), the days of oocyte retrieval, and other clinical parameters were evaluated in the two groups. RESULT(S): The cancellation rates in the scheduled and conventional groups were 9.6% and 4.7%, respectively. In about 75% of cycles in the scheduled group, oocyte retrieval was conducted on the scheduled day. When oocyte retrieval was scheduled for Monday through Wednesday, overtime work on the weekend could be avoided in 91% of the cycles without cancellation. The clinical PR was comparable between the two groups. CONCLUSION(S): The scheduled method of ovarian hyperstimulation for IVF-ET was useful for avoiding oocyte retrieval on the weekend.