Regulation of the motility of fowl spermatozoa by calcium and cAMP

Abstract

Using an objective light-scattering technique, it was confirmed that washed fowl spermatozoa become immotile as the temperature is raised from 30°C to the normal body temperature of 40-41°C. Motility of washed spermatozoa was restored at 40°C by the addition of caffeine or calcium, both stimulating motility to a maximum in a dose-dependent manner. Neither effector stimulated the motility of spermatozoa at 30°C. Caffeine, but not calcium, caused an increase in sperm cAMP levels at 40°C. The concentrations of calcium and cAMP in untreated spermatozoa were not significantly different in samples incubated at 30°C or 40°C.