The Mechanisms of Reversible Immobilization of Fowl Spermatozoa at Body Temperature

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Intact fowl spermatozoa became almost immotile at 40^ﾟC, but motility increased significantly at 30^ﾟC. The oxygen consumption at both temperatures was 8-11 ul O_2/10^<10> spermatozoa. Min^<-1>. The ATP concentration at 40^ﾟC was higher than that at 30^ﾟC but ADP concentration at 30^ﾟC was higher than that at 40^ﾟC. Consequently, the ATP/ADP ratio at 30^ﾟC (1.9-2.2) increased to 3.5-3.7 at 40^ﾟC. The motility of intact spermatozoa at 40^ﾟC was effectively restored by Ca^<2+>, seminal plasma and peritoneal fluid taken at the time of ovulation. In contrast, these effectors did not restore the motility of demembranated spermatozoa at 40^ﾟC. Motility of demembranated spermatozoa was restored at 30^ﾟC. These results suggest that the immobilization for fowl spermatozoa at 40^ﾟC occurs due to a decrease in flagellar dynein ATPase activity. Furthermore, the action of effectors for motility such as Ca^<2+> may not be directly on the axoneme, but mediated by solubilized substances which have bee … More n removed by demembranation of the spermatozoa.Demembranated spermatozoa, however, become motile at 40^ﾟC when 0.1-0.5 M concentrations of NH_4Cl, NaCl and KCl were added to the reactivation medium, with maximum motility at 0.2-0.3 M in all cases. The additions of NH_4Cl, NaCl and KCl also stimulated the ATPase activity of crude dynein extract. In contrast, LiCl did not appreciably affect motility and ATPase activity. These results showed that the flagellar dynein ATPase activity of fowl spermatozoa could be stimulated by the addition of certain monovalent chlorides, except LiCl, and demembranated spermatozoa might be motile at 40^ﾟC.The effects of tetraphenylboron on the motility and metabolism of fowl spermatozoa at 30^ﾟC were investigated. The motility of intact fowl spermatozoa was reduced by tetraphenylboron at concentrations that had little effect on the oxygen consumption and ATP content of spermatozoa. The inhibition of motility was reversed by the removal of tetraphenylboron. Furthermore, the addition of tetraphenylboron improved the maintenance of spermatozoa during storage. Tetraphenylboron did not affect the motility of demembranated spermatozoa, suggesting that the locus of action of tetraphenylboron is not directly on the axoneme of fowl spermatozoa. Less