Ashizawa K, Kamiya T, Tamura I, Tsuzuki Y
Laboratory of Animal Reproduction, Faculty of Agriculture, Miyazaki University, Japan.
Mol Reprod Dev. 1994 Jul;38(3):318-25. doi: 10.1002/mrd.1080380313.
The action of carnitine in regulating fowl sperm motility was investigated. As the concentration of L-carnitine was increased (0-20 mM), the motility of intact and demembranated fowl spermatozoa was reduced at 30 degrees C. Even the presence of 1 mM CaCl2 before the addition of 10 mM carnitine could not prevent the inhibition of motility at 30 degrees C and 40 degrees C. However, motility was restored by reducing the concentrations of carnitine. Carnitine also inhibited the oxygen consumption and ATP concentrations of intact spermatozoa, and caused a reduction in intracellular free Ca2+ concentrations. Phosphorylation of a 50 kDa protein and dephosphorylation of 24 kDa and 30 kDa proteins of demembranated spermatozoa were observed after the addition of carnitine. In contrast, the flagellar ATPase activity of crude dynein extract was not affected by the addition of carnitine. These results suggest that inhibitory effect of carnitine for motility may be directly on the axonemal phosphoproteins, but not directly on the dynein ATPase activity. The physiological role of carnitine for fowl spermatozoa in the ductus deferens is discussed.
研究了肉碱对家禽精子活力的调节作用。随着L - 肉碱浓度的增加（0 - 20 mM），在30℃时，完整和去膜的家禽精子活力降低。即使在添加10 mM肉碱之前加入1 mM CaCl2，也无法防止在30℃和40℃时精子活力受到抑制。然而，通过降低肉碱浓度可恢复精子活力。肉碱还抑制完整精子的耗氧量和ATP浓度，并导致细胞内游离Ca2 +浓度降低。添加肉碱后，观察到去膜精子的一种50 kDa蛋白发生磷酸化，24 kDa和30 kDa蛋白发生去磷酸化。相反，粗制动力蛋白提取物的鞭毛ATP酶活性不受肉碱添加的影响。这些结果表明，肉碱对精子活力的抑制作用可能直接作用于轴丝磷蛋白，而不是直接作用于动力蛋白ATP酶活性。本文还讨论了肉碱在家禽精子在输精管中的生理作用。
