乙醇毒染大鼠睾丸总抗氧化能力、一氧化氮和一氧化氮合酶的变化与生殖细胞凋亡的关系

目的:探讨饮酒大鼠睾丸总抗氧化能力(T-AOC)、一氧化氮(NO)含量和一氧化氮合酶(NOS)活性的变化与生殖细胞凋亡的关系。方法:20只成年健康SD雄性大鼠随机均分为对照组和实验组,实验组和对照组分别用50%的乙醇溶液和蒸馏水按10 m l/kg每晚灌胃1次连续26 d(两个生精周期)后,用硝酸还原酶法测定睾丸组织中NO含量;用化学比色法测定其T-AOC和NOS活性;原位缺口末端标记(TUNEL)法检测生殖细胞凋亡指数(AI)的变化。结果:与对照组相比,实验组生殖细胞AI增加(P<0.01);睾丸组织T-AOC极显著下降(P<0.01),而NO含量明显上升(P<0.01)、NOS活性显著增强(P<0.01)。结论:大量饮酒能诱导生殖细胞凋亡增加,NOS活性增强导致NO的过量产生及T-AOC的显著下降是其重要原因。     

EFFECTS OF PROGESTOGENS ON LIPEMIA AND LIPOLYSIS IN RAT: EFFECTS OF PROGESTERONE, MEGESTROL ACETATE, NORETHINDRONE ACETATE, AND NOMEGESTROL ACETATE

Effects of 4 progestogens at equal dosages (5 mg/kg/day) on lipid metabolism and plasma glucose levels of adult female rats were compared. The 4 progestogens studied were progesterone (P) by SC injection, and megestrol acetate (MEG), norethindrone acetate (NOR), and nomegestrol acetate (NOM) PO. MEG, a 17 alpha-hydroxyprogesterone derivative, induced significant increases in glucose, total and high-density lipid (HDL) cholesterol, triglyceride, and phospholipid plasma levels. Treatment with NOR, a 19-nortestosterone derivative, resulted in a reduced gain in body wt and in a marked decrease in all plasma lipid parameters. The 19-norprogesterone derivative NOM, like P, did not alter lipid or glucose metabolism, despite a significant increase in body wt gain. In particular, no reduction in the HDL cholesterol level occurred. Plasma and tissue lipolytic activities remained unchanged. The results of this study confirm interest in the therapeutic class of 19-norprogesterone-derived progestogens, exemplified by NOM, with respect to their lack of metabolic side effects.     

Identification of the C-terminal flanking peptide of preprocholecystokinin in rat brain by a novel radioimmunoassay

The C-terminal flanking peptide of preprocholecystokinin (preproCCK) has been identified in extracts of rat brain using a novel radioimmunoassay. There is a single form of immunoreactive material on gel filtration, ion exchange and reversed-phase HPLC. The C-terminal preproCCK immunoreactivity had a similar pattern of distribution to CCK8 in different regions of rat brain. This assay should help in studies of neuronal CCK biosynthesis.     

辛伐他汀对早期糖尿病大鼠视网膜白细胞黏附的影响

目的 观察辛伐他汀（Sim）对白细胞在早期糖尿病大鼠视网膜毛细血管中黏附、堆积的影响,探索他汀类药物可能的非调脂性治疗作用.方法 Wistar大鼠40只,随机分为正常对照组、糖尿病组（DM）、糖尿病Sim组（DMsim）和糖尿病生理盐水组（DM saline）.腹腔注射链脲佐菌素（STZ）建立糖尿病模型,成模后Sim组予以Sim15 mg/（kg·d）;DMsim组等量灌胃,2周后处死动物,取右眼制备视网膜石蜡切片,行形态学观察及CD45-MAb免疫组织化学研究.结果 CD45在正常大鼠视网膜血管内皮细胞胞膜中有表达,DM组CD45的表达明显增加,与正常对照组、DMsim组比较差异有统计学意义（P＜O.05）.结论 早期糖尿病大鼠视网膜白细胞黏附性增加,Sim可显著地抑制白细胞在视网膜中的黏附和堆积,改善糖尿病大鼠视网膜微循环.     

IL-2-PE40体外抑制γ-干扰素诱导的角膜内皮细胞MHC抗原表达的研究

目的了解正常大鼠角膜内皮细胞在体外经γ-干扰素诱导后，主要组织相容性复合体（major histoeompatibility complex，MHC）-Ⅰ、Ⅱ类抗原异常表达的情况。并观察比较白细胞介素-2-绿脓杆菌外毒素（interleukin-2-pseudomonas exotoxin40。IL-2-PE40）、环胞霉素A（cyclosporine A，CsA）对角膜内皮细胞MHC-Ⅰ、Ⅱ类抗原异常表达的免疫抑制作用。方法采用ACAS-570黏附式细胞分析仪和免疫荧光技术，对体外原代培养经γ-干扰素诱导后的正常大鼠角膜内皮细胞分成A、B2组进行MHC-Ⅰ、Ⅱ类抗原表达的相对量测定，并在培养液中加入新型免疫抑制剂IL-2-PE40和CsA，进一步测定角膜内皮细胞MHC-Ⅰ、Ⅱ类抗原的表达量。结果未加入γ-干扰素前，MHC-Ⅰ类抗原的表达量为97．8±8．1，MHC-Ⅱ类抗原无表达；经γ-干扰素诱导后，MHC—Ⅰ类抗原的表达量为1006．3±13．2，MHC-Ⅱ类抗原表达量为406．5±10．5，γ-干扰素加入前后MHC-Ⅰ、Ⅱ类抗原比较均有统计学意义（P〈0．05）。IL-2．PE40组MHC-Ⅰ类抗原的表达量为618．2±13．5，MHC-Ⅱ类抗原表达量为204．5±7．8，CsA组MHC-Ⅰ类抗原的表达量为609．5±12．9，MHC-Ⅱ类抗原表达量为198．5±6．9，IL-2．PE40组、CsA组分别与注射用水比较，MHC—Ⅰ、Ⅱ类抗原间均有统计学意义（P〈0．05）。IL-2．PE40组与CsA组比较．MHC—Ⅰ、Ⅱ类抗原间差异无统计学意义（P〉0．05）。结论在体外，γ-干扰素可诱导角膜内皮细胞MHC-Ⅰ、Ⅱ类抗原异常表达；IL-2-PE40及CsA均能不同程度的抑制这种表达。[眼科新进展20ff7；27（3）：170．172]     

尼莫地平对阿尔茨海默病大鼠脑组织NO、NOS含量及行为学的影响

目的：探讨尼莫地平对阿尔茨海默病（AD）大鼠脑组织一氧化氮(NO)、一氧化氮合酶（NOS）浓度及行为学改变的影响。方法：SD大鼠30只，随机分为空白对照组,AD模型组和尼莫地平组，采用大鼠脑组织立体定位微量注射技术，尼莫地平组和AD模型组用鹅膏蕈氨酸（IBO）1μl(5μg)损毁大鼠双侧迈内特基底核（nbM）建立AD动物模型，空白对照组以0.1mol/L pH7.4PB液代替IBO。尼莫地平组给予尼莫地平0.5mg/kg，空白对照组和AD模型组以生理盐水代替尼莫地平，连续灌胃60d，每d2次，每次2ml。做迷宫试验及跳台试验测学习记忆能力，然后将大鼠断头处死，分离海马及大脑皮质，分别检测NO,NOS含量。结果：AD模型组较空白对照组学习记忆能力显著降低，海马及大脑皮质NO,NOS含量显著升高，尼莫地平较AD模型组学习记忆能力显著升高，海马及大脑皮质NO、NOS含量显著降低。结论：用IBO损毁大鼠双侧nbM可建立AD动物模型，尼莫地平可显著改变AD模型大鼠的学习记忆能力，降低海马及大脑皮质NO、NOS含量。     

一氧化氮及一氧化氮合酶在遗传性癫痫易感大鼠惊厥发作中的作用

目的：探讨一氧化氮、一氧化氮合酶在遗传癫痫易感大鼠惊厥发作中的变化及作用。方法：选择惊厥评分在30－40的P77PMC大鼠35只，均分A－G7组，A组为对照组、G组预先30min腹腔注射一氧化氮合酶抑制剂L－NAME，分别于铃声刺激致惊后0．5、1、2、4,12h断头处死，取出脑组织分离双侧大脑皮层、海马等组织匀浆，测定一氧化氮及一氧化氮合酶，分别统计并进行t检验。结果：惊厥后0．5－1h皮层、海马一氧化氮、一氧化氮合酶逐渐升高，2h达峰值，4－12h恢复正常，应用L－NAME后，一氧化氮、一氧化氮合酶升高被抑制，但大鼠惊厥评分增高并致1例惊厥后死亡和明显延长惊厥持续时间。结论：惊厥后大鼠体内一氧化氮、一氧化氮合酶合成增加，给予合成酶抑制后能明显下降，但能加重惊厥程度和延长持续时间，提示一氧化氮于惊厥后升高，可能作为内源性抑制性性质，在惊厥发作自行终止机制中具有重要作用。     

Transplantation of central nervous tissue

Studies of post-lesional reorganization of central nervous connections have shown that central nerve fibers respond to nearby denervation by sprouting and formation of new terminals. The connections in the central nervous system (CNS) are accordingly much more plastic than was thought for a long time. This has revived the interest in transplantation of central nervous tissue. In this study we present some historical data on CNS transplantation supplemented by recent results obtained in our laboratory. Pieces of hippocampal tissue from embryonic or early postnatal rats were transplanted to different parts of the brain of littermates or adult rats. About two-thirds of the transplants were recovered after survival times ranging from 4 d to 2 years, and their cytological organization and intrinsic connections were monitored by cell and fiber stains and histochemical methods (AChE staining and Timm sulphide silver method). Comparison with both a normal and a lesioned control material revealed that in most transplants the tissue had developed as it does when left in situ in the donor brain, but deprived of its major afferent connections. In several instances we found evidence of a major exchange of connections between the transplants and host brains. The conditions needed for this to occur appeared to involve growth stimulation of host brain fibers by transection (host to transplant) and denervation of host neuropil (transplant to host). In cases where these conditions are met, the use of transplants may have future implications in attempts to repair lesions in the central nervous systems.     

Characterization of ramified microglia in tissue culture: pinocytosis and motility

Functional properties of ramified microglia were investigated in primary cultures of rat cerebral cortical cells. These microglia could be readily identified in both fixed and living cultures through previously established features. Based on their destruction by 5 mM L-leucine methyl ester, a high level of intrinsic endocytotic activity was established. When cultures were incubated with fluorescent latex beads to assess phagocytosis, little or no such activity was exhibited by ramified cells. However, when cultures were incubated with dyes or other soluble tracer compounds, these cells always exhibited labeling. This labeling was selective for ramified microglia in the cultures and was demonstrated using a variety of compounds, including trypan blue, lucifer yellow, horseradish peroxidase (HRP), and India ink. Intracellular label could be observed in vesicular structures; this localization corresponded to an active cellular process. Also, cellular labeling was inhibited by the presence of colchicine. These features supported the inference that the labeling was attributable to pinocytosis, and this process appeared to account for the vast majority of endocytotic activity in the ramified microglia. Possible physiological significance of this pinocytotic activity was indicated by the accumulation of various neurotransmitters/modulators: gamma-aminobutyric acid and vasoactive intestinal polypeptide (VIP). Ramified cells in these cultures have been previously noted to exhibit a constant and rapid pattern of motility, which was consistently observed here through time-lapse video recording; pinocytosis and rapid motility were shown to concur in individual cells. Based on their high intrinsic pinocytotic activity and pattern of cellular motility, the ramified microglia specifically are suggested to serve a constitutive function of fluid cleansing within the interstitial spaces of brain tissue.     

Light and electron microscopic immunocytochemistry of GRF-like immunoreactive neurons and terminals in the rat hypothalamic arcuate nuclues and median eminence

Growth hormone-releasing factor (GRF) synthesizing neuronal perikarya and terminals were investigated by light and electron microscopic immunocytochemistry using rat hypothalamus. Immunoreactive neuronal perikarya were located mainly in the ventrolateral part of the arcuate nucleus. They contained well developed cell organella such as mitochondria and rough surfaced endoplasmic reticulum with some expansion. They also contained immunoreactive dense granules (80-120 nm in diameter). On the surface of the immunoreactive neuronal perikarya were frequently found non-immunoreactive axo-somatic synapses. Therefore, the GRF-like immunoreactive neurons were assumed to receive neuronal inputs from other neurons on their neuronal soma. In the external layer of the median eminence large numbers of immunoreactive terminals were distributed particularly around the capillaries of the portal vessel. Electron microscopic immunocytochemistry revealed large numbers of immunoreactive terminals containing immunoreactive dense granules, synaptic vesicles and mitochondria in the vicinity of the basement membrane of the pericapillary space of the portal vessel. Therefore, we concluded that GRF-like immunoreactive substances are released into the portal capillaries from the nerve terminals, which originate from the neuronal perikarya in the ventrolateral part of the arcuate nucleus, and act on growth hormone release in the anterior pituitary. We also suggest that GRF-like immunoreactive neurons have abundant terminal arborization in the external layer of the median eminence.