Abstract
In the Western world, 10-15% of couples in the fertile age range have major difficulties, temporary or permanent, in procuring a pregnancy. The male partner is believed to contribute significantly to the problem in approximately 50% of the cases, usually because of disturbances in the quality of spermato- zoa. After depositing the sperm cells in the vagina they have to swim a long distance from the orifice of the cervix to the site of fertilization. The sperm must be able to swim straight forward at high speed (progressive motility) to succeed in fertilizing the egg. Asthenozoospermia, the state in which a large proportion, if not all, of the sperm cells exhibit abnormally low motility, can be the end result of a disturbance in one or more of many biochemical steps in the chain reaction of motility activation or a single structural fault in many of the complex anatomical components in the sperm flagellum. It can also reflect an adverse external environment which prevents the sperm from swimming at speed. With the advent of the modern generation of sperm motility analyzers, objective measurements could be provided on the effects of different drugs and substances on sperm progressive motility. In the present thesis I attempt to answer the following