Isolation and Characterization of the Cytoplasmic Droplet in the Rat

Abstract

A method for isolating mature and immature cytoplasmic droplets from rat sperm in the epididymis has been developed by taking advantage of the preferential adherence of sperm flagella to dry glass wool. Acid and alkaline phosphatase, β-galactosidase, β-glucosidase, aryl sulfatase A and B, DNAase, acid and alkaline protease, and hyaluronidase activities were investigated in both the immature and the mature droplets. In all cases, the activity in the immature droplets was greater than in the mature droplets. Both mature and immature droplets were able to synthesize inositol from glucose with considerably greater synthesis taking place in the immature droplet. These observations are consistent with the suggestion that the droplet is important in sperm maturation in the epididymis, possibly through its role in inositol synthesis and metabolism.