The maintenance of motility and the survival of rat epididymal spermatozoa kept at 37° C have been investigated. While progressive motility of long duration was observed when the epididymal spermatozoa of the hamster, guinea-pig and rabbit were suspended in balanced salt solutions, rat epididymal spermatozoa became immotile within 1 to 2 hr. The factor missing from the salt solutions which can maintain the motility of rat spermatozoa was shown to be present in the secretion from the seminal vesicles, epididymis and coagulating gland of the rat. The most effective factor occurred in the secretion of the seminal vesicles of the hamster, and was found to be unstable, thermolabile and undialysable through the collodion bag filter which retains proteins of a molecular weight of approximately 70,000 to 100,000. By means of electrophoretic separation, three fractions with the low mobility of serum γ and β-globulins were detected in the fresh secretion of the seminal vesicles of the hamster. The motility of rat epididymal spermatozoa was better maintained in solutions containing protein, such as albumin, α-globulin, or peptides like glutathione or cysteine. It appears that a non-specific protein which is supplied by the seminal vesicles is necessary to maintain the motility of rat spermatozoa.
If the inline PDF is not rendering correctly, you can download the PDF file here.