Effects of calcium chelators, divalent cations and sulfhydryl reagents on calcium uptake and motility of bovine spermatozoa

Effects of manganese and other divalent cations on progressive motility of human sperm

Manganese (Mn2+) stimulated the progressive motility of human washed sperm in a time- and dose-dependent manner. This confirmed previous data indicating a capacity for activating the adenylyl cyclase of sperm homogenates in vitro. A maintained response was best seen with doses 0.2-1.0 mM. After an initial stimulation, higher concentrations of up to 20 mM were associated with a decline in the response to control levels. Magnesium ions (Mg2+) stimulated motility in the same dose range but to less than 50% of the Mn2+ response. Other divalent cations such as zinc (Zn2+), strontium (Sr2+), and Calcium (Ca2+) also exerted stimulatory effects to varying degrees in descending order. Metal ion effects on sperm motility may be mediated through a common cation-binding site on the adenylyl cyclase.