A Substance Enhancing Sperm Motility in the Ovarian Fluid of Rainbow Trout

inorganic and organic components by routine methods with the following results: Na 0.16 meq/ml, K 0.34 meq/ml, Ca 0.1 mg/ml, P 0.06 mg/ml, Cl 0.14 meq/ml, carbohydrate (as glucose) 0.24 mg/ml, protein-N 2.8-3.1 mg/ml, NH3-N 2.1 ƒÁ/ml, and urea-N as trace. As shown in Fig. 1, both carbohydrate and protein appeared in the effluents from Fr. No. 6 to Fr. No. 13 with a maximum at Fr. No. 8 and a shoulder at Fr. No. 10 where the void volume was 105 ml. Fr. No. 10 showed the enhancing effect (+++) for 9 min. and Fr. No. 8 and 9 (+++) for 2 to 5 min. Other fractions showed only slight effect of (++) and less than 1 min as in the case of fresh water. From these results, a substance both enhancing sperm motility and prolonging survival time of sperm in the ovarian fluid of rainbow trout was thus found to be fractionated with gel filtration. It was postulated to be of a comparatively small molecular weight between 1,000 to 3,000. Its isolation and characterization are now under progress. Tamao YOSHIDA and Minoru NOMURA** Tokyo University of Fisheries, Minato-ku, Tokyo Reference 1) M. NOMURA: This Bull., 30, 723-733 (1964)