SUBCELLULAR SITE OF ANTISPERMATOGENIC EFFECT OF GOSSYPOL AND ITS POSSIBLE MOLECULAR MECHANISM OF ACTION

This paper reports the results of gossypol effects on the testicular mitochondrial ultrastructures and functions. A hypothesis of mechanism of gossypol action based on our experimental data was postulated.Electron microscopic observations confirmed further our previous studies that the mitoehondria of the target germ cells were the most sensitive and the most severely damaged among cellular organelles in response to gossypol. The damages included the swelling, vacuolation, crista depletion, lysis, granular accumulation in matrix and the process of intact mitochondria disintegration. The activity of the mitochondrial marker enzyme, the LDH-X of human spermatozoa, was markedly decreased or suppressed completely after gossypol treatment.The functions of isolated testieular mitochondria determined by Warburg manometric and oxygen electrode polarographic methods indicated that gossypol stimulated respiration but inhibited slightly the oxidative phosphorylation at low concentrations (20-40μM) in vitro. With     

棉酚对大鼠抗精子发生作用的细胞学、放射自显影及超微结构的观察

本文报道棉酚干扰大鼠睾丸精子发生过程及其作用部位的细胞学、放射自显影和超微结构的观察结果。睾丸生精上皮在眼药2—3周后开始出现细胞损伤;4周后精子细胞和中、晚期精母细胞大部退化消失,严重损伤的曲细精管萎缩变形,只残存以支持细胞和精原细胞为主的网状结构,间质细胞和附睾管未见有形态损伤,附属性腺亦无改变。细胞学和并合~(14)C-赖氨酸、亮氨酸和精氨酸的放射自显片观察均证明精子细胞和精母细胞出现损伤的时间最早,破坏程度最严重,是对棉酚最敏感的生精细胞,电子显微镜下亦可见这两类细胞出现明显的超微结构改变,其中变态晚期精子细胞的线粒体损伤最为明显,精原细胞仍保持并合~3H-胸腺嘧啶核苷的能力,表明不同生精细胞对棉酚有不同的敏感性。根据上述结果,文中对棉酚抗精子发生的作用部位、途径及其意义进行了分析和讨论。     

大鼠有核红细胞与小鼠浆细胞瘤(SP~2/O)细胞杂交后的细胞表型特性分析

本文选用从大鼠胚肝中分离的有核红细胞(中、晚幼成红细胞)与小鼠浆细胞瘤(SP~2/0)细胞杂交,分析自然去核前的红细胞胞质对骨髓瘤细胞核恶性增殖的调控作用,以及晚幼期固缩核重新被激活的可能性。实验结果表明:(1)杂种细胞出现了与网织红细胞杂交同样的恶性表型逆转和去恶性化的特征,验证了我们有关哺乳类红细胞中存在调节恶性分裂物质的论点,这种物质在排核前的中、晚幼成红细胞中早已出现;(2)组化染色及蛋白电泳分析显示杂种细胞中出现正常分化的大鼠和小鼠珠蛋白基因产物血红蛋白,小鼠珠蛋白基因探针的分子杂交试验证明有小鼠珠蛋白基因的表达活动;(3)大鼠晚幼期固缩核于杂交后被重新激活而出现大鼠型珠蛋白基因产物血红蛋白。     

胞质因子对人早幼粒白血病细胞恶性表型和基因表达的调控作用

本文利用胞质杂交的细胞工程手段,研究人早幼粒白血病细胞突变株在添加小鼠网织红细胞胞质后的细胞恶性表型表达状态。实验结果表明,HGPRT~-人早幼粒白血病细胞突交株(HL-60-AR)与小鼠网织红细胞融合所形成的胞质杂交细胞,其恶性程度较亲本瘤细胞显著降低,它们在体外软琼脂培养基上不能形成集落,在裸鼠体内丧失致瘤能力,同时细胞增殖率降低,细胞分裂指数下降,DNA合成速率减慢。利用c-myc癌基因探针的分子杂交技术,未检测到胞质杂交细胞存在相当于c-myc基因特异的同源序列mRNA,提示杂交细胞癌基因表达严重受抑。对杂交细胞珠蛋白在翻译和转录水平上的表达分别进行探测,结果一致显示胞质杂交细胞中人珠蛋白基因受到激活。上述结果提示,小鼠网织红细胞中存在能调控人肿瘤细胞恶性表型和基因表达状态的胞质因子。     

棉酚抗精子发生的亚细胞作用位点及其作用机理假说

本文报道棉酚对睾丸线粒体功能及超微结构的影响,并根据实验结果提出棉酚作用机理假说。 电镜观察证明生精细胞线粒体是对棉酚最敏感和损伤最严重的细胞器,呈现由肿胀、空泡化、嵴突缺损、溶解,到整体崩解等损伤过程。精子线粒体特异的乳酸脱氢酶同功酶(LDH-X)在服棉酚后明显受到抑制。 用Warburg呼吸器和Clark氧电极测定结果表明棉酚到达一定浓度后可完全抑制离体睾丸线粒体的呼吸(300μM)和氧化磷酸化(80μM)过程,其解偶联作用与剂量大小成正相关。大鼠口服棉酚后分离的睾丸线粒体的P/O值亦同样呈现非常明显的降减。 ~(14)C-棉酚对精子线粒体有较高亲和性,其分布量较其他亚细胞组分高2—3倍.与~(3)H-哇巴因一起示踪定位亦得到类似的结果。 对棉酚的亚细胞作用位点及其中断精子发生的分子作用机理以及不同细胞类型对棉酚的敏感性等问题进行了分析和讨论。     

STUDIES ON THE CELL PHENOTYPE CHARACTERISTICS OF HYBRID CELLS CROSSED BETWEEN RAT NUCLEATED ERYTHROBLASTS AND MOUSE PLASMOCYTOMA (SP~2/O) CELL LINE

The present study is designed to investigate the regulatory effect of mammalian erythroblasts, prior to naturally-occurring denucleation, on malignancy of mouse plasmocytoma cells and the possibility of reactivation of the pyknotic late erythroblast nuclei in hybrid cells crossed between rat intermediate or late erythroblasts of 15-day Wistar rat embryonic livers, and mouse plasmocytoma (SP~2/O) cell lines. Results indicated that:(ⅰ) Suppression of tumorigenicity and reversion of the malignant phenotype were observed in hybrid cells in a similar way as those of cybrid cells crossed between reticulocytes and myeloma cells as we reported previously, thus providing further evidence to support the hypothesis that some regulatory substances already existed in mammalian intermediate and late erythroblasts long before nuclear extrusion. (ⅱ) Appearance of positive histochemical reaction for hemoglobins in cytoplasm and electrophoretic bands of rat and mouse globin chains in hybrid cell lysate were i. The tran