水稻不育花药中H_2O_2的积累与膜脂过氧化的加剧

水稻7017、二九矮细胞质雄性不育系及其保持系花药的POD,CAT和SOD活性研究的结果表明,单核早期时不育及可育花药的酶活性差异不明显,单核晚期、二核及三核期的不育花药显著低于可育花药。在不育花药中缺少两条Cu-Zn SOD同工酶带,而且O_2~ 产生效率为可育的4.1～5.5倍,并有H_2O_2和MDA的积累。不育花药中H_2O_2的积累和膜脂过氧化的加剧可能与花粉败育有关。     

噪声对海马CA3区神经元电活动及突触超微结构的影响

本文用电生理学方法及电镜技术研究105dB(A)白噪声对海马CA3区神经元电活动及突触超微结构的影响。结果表明:大鼠在强噪声暴露期间(5min),其神经元放电出现减频反应(占53.3％),增频反应(占20％)和基本无反应(占26.7％)。而强噪声定时重复暴露(每天1h共50天)后,单位放电频率极显著地低于对照组,以及高频单位消失而低频单位增加;同时,突触超微结构(大鼠和豚鼠)也出现小泡不集中于突触前膜和线粒体空泡化增多等不利于突触功能的变化。表明强噪声对海马CA3区神经元的影响是明显的,且以抑制性作用更为显著。本文结合本室以往工作进行讨论,认为噪声影响学习功能可能有通过影响海马的活动而作用的机制。     

伤害性刺激和非伤害性刺激对大鼠丘脑后核神经元电活动的影响

用微电极细胞外记录的方法,观察内脏痛、躯体痛和触觉刺激对大鼠丘脑后核(PO)中770个神经元电活动的影响,其中305(38.3％)个对伤害性刺激起反应,103(13.4％)个对触觉刺激起反应。对伤害性刺激反应的神经元中多数对躯体痛和内脏痛刺激均起反应且反应形式相同,少数反应不同或相反,对触觉刺激反应的神经元中多数也对两种伤害性刺激均起反应,只对触觉刺激反应的神经元很少。     

在被小泡参与突触前后膜特化增厚的形态学研究

Our object was to characterize the morphological changes of coated vesicles and synaptic membranes during synaptogenesis. Neurons from spinal cords of fetal mice were established as isolated cells in primary culture. After a few days in vitro, the neurons extended their neurites and started their interaction. At timed intervals thereafter, cultures were fixed for electron microscopic observation. Coated vesicles were prominent in the neuronal cytoplasm at the time of synaptogenesis (about 7-10 days in vitro). Similar vesicles were seen in continuity with some cisternae in the Golgi regions and there was an increase in number during the synaptogenic period. Indeed it is not established whether the coated vesicles were exocytotic or pinocytotic in nature, but the cisternae which were in continuity with coated vesicles could be labelled by glucose-6-phosphatase (G6Pase) but not by thiamine pyrophosphatase (TPPase). Such vesicles were also seen in continuity with the neuronal plasmalemma near the closest contact site and contributed their undercoating to pre- and postsynaptic densities. The formation of bilateral membrane specialization was described as being structurally similar to synaptic active zones and appeared to be the first definitive sign of synapseformation. It has been suggested that the synaptic dense material may derive wholly or in part from the exocytic coated vesicles which apparently budding off from endoplasmic reticulum cisternae. This incorporation could provide the mechanism for confining specific characteristics of neuronal membrane to the synaptic region.     

异丙肾上腺素和氨甲酰胆碱对心肌延迟后除极的影响

用乙酰毒毛旋花子甙元2.0×10~(-7)mol/L,在绵羊心室浦肯野纤维产生延迟后除极(DAD)为实验模型,观察异丙肾上腺素与氨甲酰胆碱对DAD的影响。异丙肾上腺素1.0—3.0×10~(-8)mol/L能增加DAD幅值,为剂量依赖性,并可诱发出触发型心律失常。氨甲酰胆碱2.0×10~(-6)mol/L单独作用对DAD幅值无影响,然而在异丙肾上腺素增强DAD幅值或产生触发型心律失常后,同样浓度的氨甲酰胆碱能显著地减小DAD幅值以及消除触发型心律失常。但氨甲酰胆碱对由高钙、氨茶碱和组胺等所增加的DAD幅值却无抑制作用。以上结果表明,氨甲酰胆碱能拮抗异丙肾上腺素引起的DAD增强作用,可能与M受体的激活,并继而降低膜上β受体激活时所提高的腺苷酸环化酶活性有关。     

不同进化类型大豆种子超氧物歧化酶的比较

本文对不同进化类型大豆种子超氧物歧化酶(SOD)进行了比较分析。结果表明:(1)供试三种进化类型大豆种子的 SOD 同工酶酶谱一致,均为7条,其中一条为 Ma-SOD,其余6条为 Cu-Zn-SOD。(2)SOD 活性表现为:野生类型明显高于中间类型,中间类型明显高于栽培类型。(3)随着大豆籽粒百粒重的增大,种胚的 SOD 活性降低。(4)种皮颜色由黑到黄,种皮的 SOD 活性降低。讨论了大豆种子 SOD 活性与 Sofa 亚属内大豆进化的关系。     

树鼩(Tupaia belangeri chinensis)的脑底动脉环

用25只树鼩,从升主动脉灌注带色的橡胶乳液,在解剖显微镜下进行解剖观察,用目测微尺进行测量。大多数树鼩(22只)有完整的脑底动脉环。由左、右大脑前动脉向内侧各发一前交通动脉组成大脑前总动脉。前交通动脉口径为大脑前动脉的75～85％。后交通动脉口径与大脑后动脉相近,连于颈内动脉与大脑后动脉(基底动脉的分支)之间。测量了组成脑底动脉环有关动脉的口径。由于后交通动脉足够粗大,只有中断左、右颈总动脉和左、右椎动脉,才能造成全脑缺血。