Requirement of serum factors for capacitation and the acrosome reaction of guinea pig spermatozoa in buffered medium below pH 7.8.
Requirement of serum factors for capacitation and the acrosome reaction of guinea pig spermatozoa in buffered medium below pH 7.8.
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豚鼠精子在pH 7.8以下缓冲介质中获能和顶体反应所需的血清因子。
DOI：
10.1095/biolreprod24.2.257
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发表时间：
1981
影响因子：
3.6
通讯作者：
Garbers,DL
中科院分区：
文献类型：
--
作者：
Hyne,RV;Garbers,DL
在pH8.3 -8.4的各种缓冲液中，豚鼠精子顶体反应在30 min后开始出现，2 h时达到高峰。然而，如果将培养基的pH调节至pH 7.4，精子在8小时内不发生顶体反应。随后的实验表明，顶体反应不会自发诱导低于pH值7.8，而在pH值10.5 - 85%的能动精子显示顶体反应在5分钟内。同样，顶体反应可以最大限度地诱导在40分钟内在pH值9.5孵育的精子。在高pH下诱导顶体反应需要Ca ~（2+）的存在，因为当用1 mM Mg ~（2+）和0.2mM乙二醇-双（β-氨基乙基醚）N，N ′-四乙酸（EGTA）代替Ca ~（2+）时没有观察到顶体反应。然而，如果向培养基中加入20%（v/v）热处理的豚鼠血清或人血浆，则在pH值小于7.8时发生顶体反应。通过超滤或透析分离血清或血浆，低分子量部分（<1000）和较大分子量部分（MW 30，000 - 100，000）似乎是诱导顶体反应所需的。精子在pH8.3的无Ca ~（2+）培养液中获能，然后转移到pH7.4的无Ca ~（2+）培养液中，在无生物学因素的条件下，加入Ca ~（2+），精子立即发生顶体反应，但如果细胞在pH7.4的无生物学因素的条件下孵育3 h，然后转移到pH8.4的无Ca ~（2+）培养液中，仍需要正常的获能时间。这些结果表明，尽管豚鼠精子在碱性pH值（>7.8）下在不存在添加的生物因子的情况下可以通过顶体反应对添加的Ca 2+进行获能和响应，但是在较低pH值下需要添加的生物因子来使细胞获能。
In a protein-deficient minimal culture medium containing various buffers at pH 8.3–8.4, acrosome reactions of motile guinea pig spermatozoa were first evident after 30 min and maximal by 2 h. If the pH of the culture medium was adjusted to pH 7.4, however, spermatozoa did not undergo acrosome reactions within 8 h. Subsequent experiments showed that acrosome reactions were not spontaneously induced below pH 7.8, whereas at pH 10.5 ∿85% of the motile spermatozoa showed acrosome reactions within 5 min. Similarly, acrosome reactions could be maximally induced within 40 min in spermatozoa incubated at pH 9.5. The induction of acrosome reactions at high pH required the presence of Ca2+since no acrosome reactions were observed when 1 mM Mg2+and 0.2 mM ethylcne-glycol-bis (β-aminoethyl ether) N,N'-tetraacetic acid (EGTA) were substituted for Ca2+. Acrosome reactions occurred at pH values less than 7.8, however, if 20% (v/v) of heat-treated guinea pig serum or human plasma was added to the culture medium. The serum or plasma was fractionated by ultrafiltration or dialysis, and both a low molecular weight fraction (<1000) and a larger molecular weight fraction (MW 30,000–100,000) appeared required for induction of the acrosome reaction. Spermatozoa capacitated in Ca2+-free medium at pH 8.3 and then transferred to Ca2+-free medium at pH 7.4 reponded to the addition of Ca2+with immediate acrosome reactions in the absence of biological factors, but if cells were incubated 3 h at pH 7.4 in the absence of biological factors and then transferred to medium at pH 8.4, the normal capacitation time was still required. These results demonstrate that although guinea pig spermatozoa can capacitate and respond to added Ca2+with acrosome reactions in the absence of added biological factors at alkaline pH values (>7.8), added biological factors are required to capacitate cells at lower pH values.