Laboratorio de Bioquímica Farmacológica, Departamento de Bioquímica, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Ciudad de Mexico 11340, Mexico.
Unidad de Investigación Médica en Inmunología e Infectología, Centro Médico Nacional, La Raza, IMSS, Ciudad de Mexico 02990, Mexico.
Int J Mol Sci. 2021 Jan 4;22(1):441. doi: 10.3390/ijms22010441.
Polyamines are ubiquitous polycationic compounds that are highly charged at physiological pH. While passing through the epididymis, sperm lose their capacity to synthesize the polyamines and, upon ejaculation, again come into contact with the polyamines contained in the seminal fluid, unleashing physiological events that improve sperm motility and capacitation. In the present work, we hypothesize about the influence of polyamines, namely, spermine, spermidine, and putrescine, on the activity of sperm channels, evaluating the intracellular concentrations of chloride [Cl]i, calcium [Ca]i, sodium [Na]i, potassium [K]i, the membrane V, and pHi. The aim of this is to identify the possible regulatory mechanisms mediated by the polyamines on sperm-specific channels under capacitation and non-capacitation conditions. The results showed that the presence of polyamines did not directly influence the activity of calcium and chloride channels. However, the results suggested an interaction of polyamines with sodium and potassium channels, which may contribute to the membrane V during capacitation. In addition, alkalization of the pHi revealed the possible activation of sperm-specific Na/H exchangers (NHEs) by the increased levels of cyclic AMP (cAMP), which were produced by soluble adenylate cyclase (sAC) and interact with the polyamines, evidence that is supported by in silico analysis.
多胺是广泛存在的多阳离子化合物，在生理 pH 值下带高度正电荷。精子在通过附睾时丧失了合成多胺的能力，而在射精时再次接触到精液中的多胺，引发改善精子活力和获能的生理事件。在本工作中，我们假设多胺（精胺、亚精胺和腐胺）对精子通道的活性的影响，评估氯离子[Cl]i、钙离子[Ca]i、钠离子[Na]i、钾离子[K]i、膜电位 V 和 pH 值 i 的细胞内浓度。目的是鉴定在获能和非获能条件下，多胺对精子特异性通道的可能调节机制。结果表明，多胺的存在并不直接影响钙和氯通道的活性。然而，结果表明多胺与钠和钾通道相互作用，这可能有助于在获能期间的膜电位 V。此外，pH 值 i 的碱化揭示了多胺可能通过增加的环磷酸腺苷（cAMP）水平激活精子特异性 Na/H 交换器（NHEs），cAMP 由可溶性腺苷酸环化酶（sAC）产生，并与多胺相互作用，这一证据得到了计算机模拟分析的支持。
