Ashizawa K, Wishart G J, Nakao H, Okino Y, Tsuzuki Y
Laboratory of Animal Reproduction, Faculty of Agriculture, Miyazaki University, Japan.
J Reprod Fertil. 1994 Aug;101(3):593-8. doi: 10.1530/jrf.0.1010593.
Fowl sperm motility was measured by altering the extracellular pH (pHe) at 30 degrees C and 40 degrees C. At 30 degrees C, the motility of intact spermatozoa was vigorous in a medium in the wide pHe range of 7.3-10.1. In contrast, intact spermatozoa were almost immotile at 40 degrees C in medium below a pHe of 8.1. However, the motility could be restored by increasing the pHe; maximum motility was obtained in medium at pHe 9.4. Stimulation of the motility of demembranated spermatozoa at 40 degrees C was also observed with an increased pHe. However, demembranated spermatozoa at 40 degrees C that had been stimulated by increasing the pHe lost their motility when 1 mmol CaCl2 l-1 was added. Motility was restored by the subsequent addition of 2 mmol EGTA l-1. At a high pHe at 40 degrees C, the flagellar ATPase activity of crude dynein extract was not affected, regardless of the addition of CaCl2 or EGTA. The intracellular pH (pHi) of intact spermatozoa, estimated by measuring the accumulation of 9-aminoacridine fluorescence, increased with increasing pHe at both 30 degrees C and 40 degrees C. These results demonstrate that the reversible temperature-dependent immobilization of fowl spermatozoa at 40 degrees C is inhibited by an increased pHi. Furthermore, it is possible that the effects of the increased pHi may not act directly on dynein ATPase activity, but are mediated by a Ca(2+)-related substance(s) on the axoneme.
通过改变30℃和40℃下的细胞外pH值（pHe）来测量家禽精子活力。在30℃时，完整精子在7.3 - 10.1的宽pHe范围内的培养基中活力旺盛。相比之下，在40℃时，pHe低于8.1的培养基中完整精子几乎不运动。然而，通过提高pHe可恢复活力；在pHe 9.4的培养基中可获得最大活力。在40℃时，提高pHe也能刺激去膜精子的活力。然而，在40℃时，通过提高pHe刺激的去膜精子在添加1 mmol CaCl₂ l⁻¹时会失去活力。随后添加2 mmol EGTA l⁻¹可恢复活力。在40℃的高pHe条件下，无论添加CaCl₂ 还是EGTA，粗制动力蛋白提取物的鞭毛ATP酶活性均不受影响。通过测量9-氨基吖啶荧光积累估计的完整精子的细胞内pH值（pHi）在30℃和40℃时均随pHe升高而增加。这些结果表明，40℃时家禽精子可逆的温度依赖性固定受pHi升高抑制。此外，pHi升高的影响可能不直接作用于动力蛋白ATP酶活性，而是由轴丝上与Ca²⁺相关的物质介导。
