A novel method for sperm diagnosis and selection based on chemotactic orientation towards progesterone

GATICA LV; MONTESINOS, MM; GUIDOBALDI HA; TEVES ME; UÑATES DR; GIOJALAS LC

Barcelona, España

Congreso; IX International Congress of Andrology; 2009

American Society of Andrology

The aim was to evaluate a new method to diagnose human sperm samples and to select spermatozoa at the best functional state by means of chemotaxis mediated by progesterone (P). Methods: Capacitated human spermatozoa were separated by chemotaxis towards P in a chamber consisted of two wells connected by a tube, one filled with spermatozoa and the other with the culture medium or P. The difference in the sperm count between the condition in the absence or presence of P was calculated. After defining the best experimental conditions to perform the sperm separation assay, the validation of this method was carried out with specific inhibition of membrane adenylyl cyclase (mAC), a descendant gradient of P, a comparison to chemotaxis determination by videomicroscopy, and the level of induced acrosome reaction  (AR). Results: The optimum conditions for sperm separation by chemotaxis  were:  1% human albumin, 6x10⁶ cells/ml, 10 pM P and 20 min of incubation at 37°C. A significant sperm subpopulation migrated towards P (9±0.4%; p<0.01), showing a positive correlation with the percentage of chemotactic spermatozoa evaluated by videomicroscopy (7±0.3%, r=0.79, p<0.01), and with the percentage of induced AR (8±0.8%, r=0.94, p<0.05). Sperm chemotaxis towards P was corroborated with a descendant P gradient assay (p<0.001) and by the specific inhibition of the mAC (p<0.05). Conclusions: Sperm separation by chemotaxis towards P may be considered a good parameter for human semen diagnosis, or to select spermatozoa at the best functional state to be used in assisted reproduction techniques.