Inhibition of Acrosomal Enzymes by Gossypol Is Related to Its Antifertility Action

ＩｎｈｉｂｉｔｉｏｎｏｆＡｃｒｏｓｏｍａｌＥｎｚｙｍｅｓｂｙＧｏｓｓｙｐｏｌＩｓＲｅｌａｔｅｄｔｏＩｔｓＡｎｔｉｆｅｒｔｉｌｉｔｙＡｃｔｉｏｎＹＵＡＮＹｕ－ｙｉｎｇ;（袁玉英）ＺＨＡＮＧＹａｎ－ｌｉｎ;（张燕林）ＳＨＩＱｉ－ｘｉａｎ（石其贤）（Ｚｈｅ...     

脂筏与精子膜信号传导

脂筏是细胞膜内由特殊脂质与蛋白质构成的微域。小窝是脂筏的一种形式,小窝标记蛋白有小窝蛋白和小窝舟蛋白。脂筏或小窝与生物信号传导、细胞蛋白转运和胆固醇平衡有关。最近实验证实哺乳动物精子膜具有脂筏结构,脂筏与膜胆固醇外逸对于启动受精的信号传导具有重要作用。     

孕酮诱发豚鼠精子顶体反应过程中的Ca^2＋内流通道

在体外,孕酮和γ－氨基丁酸可明显地引起豚鼠精子顶体反应,并且两者合并使用,对顶体瓜在的诱发有协同作用,这种反应不依赖于细胞外Ｃｌ＾－,在含Ｃｌ＾－培养液中,ＧＡＢＡＡ受体拮抗剂ｐｉｃｒｏｔｏｘｉｎ和ｂｏｃｕｃｕｌｌｉｎｅ不抑制孕酮诱发的顶体反应,而抑制ＧＡＢＡ诱发的顶体反应。相反在缺Ｃｌ＾－培养液中,ｐｉｃｒｏｔｏｘｉｎ则可明显地抑制孕酮和ＧＡＢＡ诱发的顶体反应。孕酮和ＧＡＢＡ诱发的顶体反应均可被     

GABA/progesterone-induced polyphosphoinositide (PPI) breakdown and its role in the acrosome reaction of guinea pig spermatozoa in vitro

To investigate whether GABA/progesterone (P4) stimulates PPI breakdown and its role in the acrosome reaction (AR), spermatozoa of guinea pig were preincubated in MCM-LCa2+ for 5.5 h and then labeled with [32P]pi for 1 h. Samples were washed through a three-step gradient Percoll, adjusted to 5×107 cells/mL and exposed to 2 mmol/L Ca2+, 5 mmol/L GABA, 10 mmol/L P4 and other agents. Lipids were separated by t.l.c. and radioactivity in spots determined by scintillation counting. The AR was assessed by phase-contrast microscopy. The results showed that (i) when spermato-zoa were treated with GABA, 32P-label diminished rapidly in phosphatidylinositol 4, 5-bisphosphate (PIP2), phosphatidylinositol 4-phosphate (PIP), and increased in phosphatidic acid (PA). The loss of label from PPI was almost completed by 10 min. The time-course of the AR was much slower than PPI when spermatozoa reached a maximal response by 15 min; (ii) the pattern of PPI hydrolysis and stimulation of AR was similar for the three agonists tested；their potency followed the order A23187＞progesterone≥GABA; (iii) GABA-induced PIP2 hydrolysis and rise in PA and the AR were prevented by inclusion of 10 mmol/L neomycin; (iv) the loss of PIP2 labeling and the increase in PA labeling abolished when spermatozoa were exposed to EGTA or Ca2+ channel blocker. These re-sults indicate that GABA or P4-induced PPI breakdown is an important and essential event in the series of changes to membrane fusion during the AR of guinea pig spermatozoa and this effect is mediated via calcium by activation of phosphatidylinositol-specific phospholipase C.     

GABA/孕酮激发豚鼠精子聚磷酸肌醇降解及其在顶体反应中的作用

为了研究GABA/孕酮(P₄)激发精子聚磷酸肌醇(PPI)降解及其在顶体反应(AR)中的作用,将豚鼠精子在MCM培养基获能培养5.5 h,³²P-标记精子1h,经Percoll密度梯度离心洗涤,然后以AR刺激剂激发精子AR,并对精子膜脂进行提取、分离和鉴定,同时,以相差显微镜评价精子AR%.结果为:(i)GABA刺激二磷酸磷脂酰肌醇(PIP₂)和一磷酸磷脂酰肌醇(PIP)迅速降解,而磷脂酸(PA)增加;在5min时PIP₂和PIP明显下降,10min几近完成,而AR明显滞后,15min才达到峰值;(ii)A23187,P₄和GABA均可激发PPI降解和AR增加,其能力依次为A23187＞P₄≥GABA;(iii)新霉素可明显地抑制Ca²⁺/GABA 或P₄及A23187刺激PIP₂和PIP降解、PA产生和AR增加;(iv)PPI降解需Ca²⁺参与.当EGTA或Ca²⁺通道阻滞剂(La³⁺)存在时,PIP₂和PIP降解,PA产生和AR升高均被明显抑制.上述结果表明,天然激动剂GABA或P₄刺激豚鼠精子膜PPI降解是引起AR的基础,该作用是通过Ca²⁺介导、激活膜磷脂酰肌醇特异磷脂酶C(PIC)而完成的.     

透明带/Ca~(2+)激活磷脂酶A_2及其在豚鼠精子顶体反应中的作用

透明带/Ca~(2+)激活磷脂酶A_2及其在豚鼠精子顶体反应中的作用@袁玉英$浙江省医学科学院!　中国　杭州310012 @石其贤$浙江省医学科学院!　中国　杭州310012 @Ers Roldan$Museo Naclonal de Cienclas,Naturales(CSIC)C/Jose Gutierrez Abaseal!28006-Madrid Spain @毛丽珍$浙江省医学科学院!　中国　杭州310012 @俞淑清$浙江省医学科学院!　中国　杭州310012 @陈文颖$浙江省医学科学院!　中国　杭州310012 @方昕$浙江省医学科学院!　中国　杭州310012…     

棉酚抗生育作用的研究 Ⅱ.对雄性大鼠的抗生育作用

早在1957年刘宝善提出了用“食用生棉油来节制生育”的刍议;但当时未引起人们的重视。此后,在我国一些产棉区因长期食用粗制棉油引起不育或生育力显著降低的启示下,自1971年以来,全国一些单位开展了棉籽仁和棉酚抗生育作用的实验研究(全国男用避孕药协作组1978)。本文以雄大鼠为模型,探讨棉酚抗生育的最低有效剂量,并分析其抗生育作用的起效和恢复时间及其作用方式,以期为临床用药提供资料。     

正常成年Wistar大白鼠的脏器重量测定

153只正常成年wistar大白鼠脏器指数测定结果表明心、肝、大脑、小脑、肾、肺、脾及肾上腺的脏器指数(X±SD)较恒定,分别为0.33±0.09,3.01±0.68,0.51±0.11,0.17±0.04,0.68±0.14,0.66±0.24,0.27±0.13 g/100g BW和20.29±8.28 mg/100g BW,胸腺和生殖系统(卵巢、子宫、睾丸)的脏器指数个体间差异较大。