INHIBITION OF BOVINE SPERMATOZOA BY CAUDAL EPIDIDYMAL FLUID .2. INTERACTION OF PH AND A QUIESCENCE FACTOR
INHIBITION OF BOVINE SPERMATOZOA BY CAUDAL EPIDIDYMAL FLUID .2. INTERACTION OF PH AND A QUIESCENCE FACTOR
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DOI：
10.1095/biolreprod30.4.926
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发表时间：
1984-01-01
影响因子：
3.6
通讯作者：
CARR, DW
中科院分区：
文献类型：
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作者：
ACOTT, TS;CARR, DW
显然，牛精子在附睾尾部 (CE) 中通过 pH 依赖性抑制因子维持静止状态。牛CE液体和CE精液的pH值为.apprx。 5.8，未稀释的 CE 液体中 CE 精子的活力随着 pH 值的升高而增加。 CE液的酸性可能在维持精子静止中发挥生理作用。精子活力的变化响应 CE 液体 pH 值的变化，是可逆且快速的。用 pH 5.5 或 7.6 的缓冲液稀释 CE 液体会产生更慢的运动启动。缓冲液中抑制精子活力所需的 pH 值比 CE 液中所需的 pH 值低得多。缓冲液中的表观抑制 pK 为 5.3，CE 液体中的表观 pK 为 6.6。精子在含有乳酸的缓冲液中的活力表现出与 CE 液体中的精子类似的 pH 依赖性。在 pH 5.5 的缓冲液中，乳酸可使精子失活，但在 pH 7.6 时则不会。乳酸和其他几种渗透性弱酸降低了牛精子和许多其他类型细胞的细胞内 pH 值。这些渗透性弱酸（而非非渗透性弱酸）在 pH 5.5 的缓冲液中可逆地降低 CE 精子的活力，但在 pH 7.6 时则不会。弱碱会提高细胞内 pH 值，从而启动 CE 液中的精子运动。细胞内 pH 显然可以调节 CE 精子的活力，并且可能是 pH 依赖性静止因子的细胞内信使。尽管精子 cAMP 水平以前与运动刺激相关，但当 CE 液体的 pH 值升高时，即使完全运动已启动，cAMP 水平也不会发生变化。
Bovine sperm evidently are maintained in a quiescent state in the caudal epididymis (CE) by a pH-dependent inhibitory factor. The pH of bovine CE fluid and of CE semen was .apprx. 5.8, and the motility of CE sperm in undiluted CE fluid increased as the pH was elevated. The acidity of CE fluid may play a physiological role in the maintenance of sperm quiescence. The changes in sperm motility, in response to changes in the pH of CE fluid, are reversible and rapid. Dilution of CE fluid with buffers at either pH 5.5 or 7.6 produced a much slower initiation of motility. In buffer a significantly lower pH was required to inhibit sperm motility than is required in CE fluid. The apparent pK for inhibition were 5.3 in buffer and 6.6 in CE fluid. The motility of sperm in buffers that contain lactate showed a pH dependence similar to sperm in CE fluid. Lactate inactivated sperm in buffer at pH 5.5 but not at pH 7.6. Lactate, and several other permeant weak acids, reduced the intracellular pH of bovine sperm and many other types of cells. These permeant weak acids, but not impermeant weak acids, reversibly reduced CE sperm motility in buffer at pH 5.5 but not at pH 7.6. Weak bases, which elevated intracellular pH, initiate sperm motility in CE fluid. Intracellular pH evidently can regulate CE sperm motility and may be the intracellular messenger for the pH-dependent quiescence factor. Although sperm cAMP levels were previously correlated with motility stimulation, cAMP levels do not change when the pH of CE fluid is elevated, even though full motility is initiated.