Influence of media and thermal shock on sperm capacitation

The effect of a two-hour, room temperature incubation of human spermatozoa in TEST-yolk buffer on the rate of fertilization in vitro

PURPOSE

To reassess the use of TEST-yolk buffer (TYB) in an in vitro fertilization (IVF) program by comparing fertilization rates achieved in a glucose-free cleavage medium by the standard IVF preparation of sperm versus a 2-h, room temperature incubation of sperm in TYB.

METHODS

Oocytes collected for IVF were randomly split into two groups and inseminated with either TYB-treated sperm or IVF-prepared sperm.

SETTING

Stanford Reproductive Endocrinology and Infertility Center.

PATIENTS

Fifty couples undergoing IVF with at least 10 mature oocytes.

MAIN OUTCOME MEASURES

Fertilization rates in vitro.

RESULTS

Fertilization rates were significantly higher (p = 0.015) with TYB treatment. The average 2PN fertilization rate was 49.6% (188/379) for the IVF group and 57.4% (221/385) in the IVF with TYB group.

CONCLUSIONS

A 2-h, room temperature incubation of sperm in TYB produces significantly higher 2PN fertilization rates as compared to standard IVF preparation of sperm in a current generation cleavage medium.

Activity of Chinchilla laniger spermatozoa collected by electroejaculation and cryopreserved

Because reproductive studies and the application of assisted reproductive techniques are relevant issues for an endangered species such as Chinchila laniger, the availability of a source of viable spermatozoa becomes of utmost importance. In this paper, we evaluate several functional parameters (motility, viability, response to hypoosmotic swelling test and acrosomal integrity) of fresh or frozen-thawed spermatozoa. Electro-ejaculation trials (50-cyc/sec sinusoidal wave was applied for 5 of every 10 sec) were successful in all unanesthetized animals. After volume (108.3 +/- 12.0 microL, n = 15) and concentration (421.8 +/- 34.4 x 10(6) cells/mL, n = 15) measurements, the above mentioned parameters were determined. In frozen-thawed semen samples sperm motility, viability, hypoosmotic swelling test and acrosomal integrity were significantly lower than in fresh semen samples. The results clearly indicated that electro-ejaculation is a useful method for evaluating spermatozoa for genetic analysis or for used in Al in this species. In addition, the cryopreservation procedure in this study preserved adequate levels of functional sperm activity.