Measurement of the motility of rat spermatozoa collected by micropuncture from the testis and from different regions along the epididymis.

Spermatozoa from the testis and various regions along the epididymis of the rat were collected by micropuncture and their motility after dilution was estimated over a 15-min period by using a Quantimet image analyser. The motility of sermatozoa from the rete testis and seminiferous tubules was too low to be measured. The estimate of motility of spermatozoa from the proximal caput epididymidis was much lower than that of spermatozoa from the other regions. Spermatozoa from the distal part of the caput showed sustained motility for 15 min, whereas those from the caudal region and ductus deferens, although active initially, became less active during this period.