Peralta-Arias Rubén D, Vívenes Carmen Y, Camejo María I, Piñero Sandy, Proverbio Teresa, Martínez Elizabeth, Marín Reinaldo, Proverbio Fulgencio
Laboratorio de Bioenergética CelularInstituto Venezolano de Investigaciones Científicas (IVIC-CBB), AP 21827, Caracas 1020A, VenezuelaDepartamento de Biología de OrganismosUniversidad Simón Bolívar, Caracas, VenezuelaLaboferclaMaternidad Leopoldo Aguerrevere, Caracas, Venezuela.
Laboratorio de Bioenergética CelularInstituto Venezolano de Investigaciones Científicas (IVIC-CBB), AP 21827, Caracas 1020A, VenezuelaDepartamento de Biología de OrganismosUniversidad Simón Bolívar, Caracas, VenezuelaLaboferclaMaternidad Leopoldo Aguerrevere, Caracas, Venezuela
Reproduction. 2015 May;149(5):475-84. doi: 10.1530/REP-14-0471.
Human sperm has several mechanisms to control its ionic milieu, such as the Na,K-ATPase (NKA), the Ca-ATPase of the plasma membrane (PMCA), the Na(+)/Ca(2) (+)-exchanger (NCX) and the Na(+)/H(+)-exchanger (NHE). On the other hand, the dynein-ATPase is the intracellular motor for sperm motility. In this work, we evaluated NKA, PMCA, NHE, NCX and dynein-ATPase activities in human sperm and investigated their correlation with sperm motility. Sperm motility was measured by Computer Assisted Semen Analysis. It was found that the NKA activity is inhibited by ouabain with two Ki (7.9 × 10(-9) and 9.8 × 10(-5) M), which is consistent with the presence of two isoforms of α subunit of the NKA in the sperm plasma membranes (α1 and α4), being α4 more sensitive to ouabain. The decrease in NKA activity is associated with a reduction in sperm motility. In addition, sperm motility was evaluated in the presence of known inhibitors of NHE, PMCA and NCX, such as amiloride, eosin, and KB-R7943, respectively, as well as in the presence of nigericin after incubation with ouabain. Amiloride, eosin and KB-R7943 significantly reduced sperm motility. Nigericin reversed the effect of ouabain and amiloride on sperm motility. Dynein-ATPase activity was inhibited by acidic pH and micromolar concentrations of Ca(2) (+). We explain our results in terms of inhibition of the dynein-ATPase in the presence of higher cytosolic H(+) and Ca(2) (+), and therefore inhibition of sperm motility.
人类精子有多种机制来控制其离子环境，如钠钾ATP酶（NKA）、质膜钙ATP酶（PMCA）、钠/钙交换体（NCX）和钠/氢交换体（NHE）。另一方面，动力蛋白ATP酶是精子运动的细胞内动力源。在这项研究中，我们评估了人类精子中NKA、PMCA、NHE、NCX和动力蛋白ATP酶的活性，并研究了它们与精子运动的相关性。精子运动通过计算机辅助精液分析进行测量。结果发现，哇巴因可抑制NKA活性，其两个抑制常数（Ki）分别为7.9×10⁻⁹和9.8×10⁻⁵ M，这与精子质膜中NKAα亚基存在两种同工型（α1和α4）一致，其中α4对哇巴因更敏感。NKA活性的降低与精子运动能力的下降相关。此外，分别在已知的NHE、PMCA和NCX抑制剂（如阿米洛利、伊红和KB-R7943）存在的情况下，以及在与哇巴因孵育后加入尼日利亚菌素的情况下评估精子运动能力。阿米洛利、伊红和KB-R7943显著降低了精子运动能力。尼日利亚菌素逆转了哇巴因和阿米洛利对精子运动能力的影响。酸性pH值和微摩尔浓度的Ca²⁺可抑制动力蛋白ATP酶活性。我们从在较高胞质H⁺和Ca²⁺存在时动力蛋白ATP酶受到抑制，进而抑制精子运动的角度来解释我们的结果。
