THE EFFECTS OF CHRONIC REGIMENS OF CLORGYLINE AND PARGYLINE ON MONOAMINE METABOLISM IN THE RAT BRAIN

The effects of chronic administration of clorgyline and pargyline on rat brain monoamine metabolism have been examined. The inhibitory selectivity of these drugs towards serotonin deamina-tion (MAO type A) and phenylethylamine deamination (MAO type B) can be maintained over a 21-day period by proper selection of low doses of these drugs (0.5-1.0 mg/kg/24h). The results are consistent with MAO type A catalyzing the deamination of serotonin and norepinephrine and with MAO type B having little effect on these monoamines. Dopamine appears to be dcaminated in vivo principally by MAO type A. Clorgyline administration during a 3-week period was accompanied by persistent elevations in brain norepinephrine concentrations; serotonin levels were also increased during the first 2 weeks, but returned towards control levels by the third week of treatment. Low doses of pargyline did not increase brain monoamine concentrations, but treatment with higher doses for 3 weeks led to elevations in brain norepinephrine and 5-hydroxytryptamine; at this time significant MAO-A inhibition had developed. The changes in monoamine metabolism seen at the end of the chronic clorgyline regimen are not due to alterations in tryptophan hydroxylase activity. At this time tyrosine hydroxylase activity was also unaffected.     

EFFECTS OF PUROMYCIN ON THE STRUCTURE OF RAT INTESTINAL EPITHELIAL CELLS DURING FAT ABSORPTION

This report provides information on the morphology of rat intestinal epithelial cells during fat absorption. In addition, the role of protein metabolism in this process has been evaluated by blocking its synthesis with puromycin and studying the fine structure of mucosal cells from rats at various times after fat intubation. The results indicate that SER-derived vesicles, containing fat droplets, migrate from the apical cytoplasm of the absorptive cell and fuse with saccules or vacuoles of the Golgi complex. Arguments are made that the Golgi complex is important in completing chylomicron formation and in providing appropriate enveloping membranes for the chylomicron. Such membranes may be necessary for Golgi vacuoles to fuse with the lateral cell membranes and release chylomicra. Puromycin treatment causes the absorptive cell to accumulate increased quantities of lipid that are devoid of membrane during fat absorption. In addition, puromycin-treated cells contain much less RER and Golgi membranes are strikingly decreased in number. In this paper we discuss the consequences of these abnormalities and suggest that continued protein synthesis by the RER is required in order to generate Golgi membranes. If such membranes are absent the cell's ability to discarge chylomicra is impaired and lipid accumulates.     

EFFECTS OF CHRONIC ETHANOL INGESTION ON BRAIN AMINOACYL-tRNA SYNTHETASES AND tRNA

The effects of chronic ethanol ingestion on the in vivo aminoacylation of brain transfer RNA (tRNA) were examined in C57BL/6J mice. A pronounced inhibition in the formation of [¹⁴C]leucy]-tRNA and [¹⁴C]phenylalanyl-tRNA was observed in the ethanol drinking mice. Properties of aminoacyl-tRNA synthetases and tRNA were examined following their separation and isolation on a DEAE-cellulose column. Synthesis of [¹⁴C]leucyl-tRNA was found to have a complete dependence on ATP and Mg²⁺. Incubations were carried out by cross-matching tRNA from control rat brain with synthetases obtained from the brains of control or ethanol-drinking mice. Under these conditions, a decreased ability for aminoacylation could be demonstrated when the source of enzyme was derived from ethanol-treated brain. The data indicate that the major effect of ethanol ingestion on the aminoacylation reaction is exerted on aminoacyl-tRNA synthetases.     

EFFECTS OF INGESTION OF A CARBOHYDRATE-FAT MEAL ON THE LEVELS AND SYNTHESIS OF 5-HYDROXYINDOLES IN VARIOUS REGIONS OF THE RAT CENTRAL NERVOUS SYSTEM

—The concentrations of tryptophan, serotonin (5-HT), and 5-hydroxyindoleacetic acid (5-HIAA) in spinal cord and most brain regions increase 2 h after fasted rats begin to consume a carbohydrate-fat meal: indole levels rise in all portions of the brain studied, but the increase is not statistically significant in the hypothalamus and corpus striatum. The rate at which the brain synthesizes 5-hydroxy-indoles (as estimated in vivo by measuring 5-hydroxytryptophan accumulation following an injection of the decarboxylase inhibitor RO4-4602) is also accelerated in all of the regions in which the experimental diet elevates tryptophan, 5-HT and 5-HIAA levels. These observations indicate that the previously reported increase in brain 5-hydroxyindole levels following consumption of a protein-free meal reflects accelerated serotonin synthesis, and occurs within both the cell bodies and the terminals of serotonin-containing neurons. It is possible that diet-induced changes in neuronal serotonin levels influence the quantities of the neurotransmitter released into synapses, either spontaneously or in response to drugs.     

慢性缺氧对大鼠肺内皮素表达的影响

本文以ＡＢＣ法和原位杂交技术,观察了慢性缺氧时大鼠肺组织内内皮素－１（ＥＴ－１）的表达情况,结果发现：①正常肺血管内皮细胞有少许ＥＴ－１样阳性染色物质呈现。②缺氧ＩＷ后,肺内ＥＴ－１含量增加,主要位于肺血管内皮细胞和支气管粘膜上皮细胞。③缺氧２Ｗ和３Ｗ后,ＥＴ１阳性免疫物质进一步增加,于肺泡细胞内也见到阳性染色。④缺氧１Ｗ后肺内ＥＴ－１ｍＲＮＡ表达增加,缺氧２Ｗ和３Ｗ后,ＥＴ－１ｍＲＮＡ的表达进一步加强。提示缺氧可刺激肺内ＥＴ－１ｍＲＮＡ的表达,慢性缺氧时肺内ＥＴ－１持续分泌增加,这可能是缺氧性肺动脉高压发生的重要因素之一。     

A SURVEY OF DEHYDROGENASES IN VARIOUS EPITHELIAL CELLS IN THE RAT

Several different epithelial elements that have intense active transport or protein secretory functions were histochemically assayed in several dehydrogenase media by a recently perfected method. The mitochondria represented the only site of activity, not only when tested in the succinate and D-β-hydroxybutyrate media, but also when tested in the lactate, malate, and isocitrate media. The reaction for D-β-hydroxybutyric dehydrogenase in the mouse kidney was curiously limited to the mitochondria of the distal segment of the proximal convoluted tubule, a finding that most convincingly shows that dehydrogenase activity may be differentiated in certain instances from diaphorase activity by the ditetrazole methods and that D-β-hydroxybutyric dehydrogenase is not present in all mitochondria. Tetranitro-BT is favored over nitro-BT in studies conducted on most organs prepared without fixation and on formalin-fixed tissues that consist of lipid-containing or active transport cells.     

THE EFFECTS OF HYPERKETONEMIA ON GLYCOLYTIC INTERMEDIATES IN THE DEVELOPING RAT BRAIN

Abstract— Newborn rats from dams fed on a high fat diet developed increased ketonemia and significant hypertriglyceridemia i.e. "hyperketonemic pups". This perinatal metabolic stress led to an alteration in the developmental pattern of glycolytic intermediates in their brains.
In control rats, the concentration of glucose 6-phosphate (G6P) in the brain was high at birth, and gradually decreased to adult values by the third week of life. In contrast, the fructose-1,6-diphosphate (FDP) concentration was low at birth and increased thereafter. The lactate concentration was also high at birth but decreased to the adult level by the first day of life. In the brains of control pups, lactate and pyruvate concentrations remained relatively constant during the first 3 weeks of life.
In the brains of hyperketonemic pups, the concentration of G6P was the same as in the control animals at birth but decreased significantly during the first days of life. During early development the concentrations of FDP and pyruvate were significantly lower and the concentration of lactate, higher in the hyperketonemic pups as compared to the control group. The alteration in the concentration of these glycolytic intermediates in the brains of hyperketonemic pups indicated a change in the developmental pattern of glycolysis. The ratio of [lactate]/[pyruvate] also suggested an increased cytoplasmic redox potential in the brains of hyperketonemic pups during the first week of life.     

大鼠肺内表皮生长因子(EGF)之分布及缺氧对其含量的影响

本文用免疫体金银法对大白鼠肺内表皮生长因子(Epidermal growth factor,EGF)进行了定位研究,并观察缺氧时肺内 EGF 含量的变化。结果显示正常大鼠肺泡细胞、支气管粘膜及肺内血管壁上均含有 EGF 免疫阳性反应物质;缺氧时,肺内 EGF 含量增加。这提示 EGF 不仅对肺具有一定的生理学影响,而且可能参与缺氧时肺的某些病理学过程。     

EDRF对PE引起的大鼠主动脉缩血管效应的作用

本文研究ＥＤＲＦ（ｅｎｄｏｔｈｅｌｉｕｍ－ｄｅｒｉｖｅｄｒｅｌａｘｉｎｇｆａｃｔｏｒ,ＥＤＲＦ）对ＰＥ（ｐｈｅｎｙｌｅｐｈｒｉｎｅ）引起的大鼠主动脉收缩反应的影响。内皮完整和去内皮的大鼠主动脉环悬挂于器官浴槽中,测定血管的张力和收缩速度的变化。所有的实验在消炎痛（ｉｎｄｏｍｅｔｈａｃｉｎ,１０μｍｏｌ／Ｌ）存在下进行。用美兰（ｍｅｔｈｙｌｅｎｅｂｌｕｅ,ＭＢ,１０μｍｏｌ／Ｌ）或左旋硝基精氨酸（ＮＧ－ｎｉｔｒｏ－Ｌ－ａｒｇｉｎｉｎｅ,Ｌ－ＮＮＡ,３０μｍｏｌ／Ｌ）处理内皮完整的大鼠主动脉环,ＰＥ的剂量－收缩张力曲线明显左移,ＥＣ３０值均降低５倍,最大反应比率分别为１．６±０．４和１．６±０．５。在去内皮的大鼠主动脉环中,经ＭＢ和Ｌ－ＮＮＡ处理后,仍可见ＥＣ３０下降３倍,最大反应比率均为１．０±０．２。后者可能与血管平滑肌产生少量ＥＤＲＦ有关。我们的结果提示ＰＥ对血管的收缩反应也受血管内皮和平滑肌产生的ＥＤＲＦ的调控     

谷氨酰胺对大鼠海马脑片谷氨酸递质释放的影响

在以前的工作中我们观察到 ,饲料中补充谷氨酰胺 (Ｇｌｎ)可使大鼠脑组织中Ｇｌｎ和谷氨酸 (Ｇｌｕ)含量升高 ,并引起一系列代谢和功能的改变。当脑组织处于丰富的Ｇｌｎ环境中时 ,Ｇｌｕ等兴奋性氨基酸的释放是否会受到影响呢 ?由于条件所限 ,在整体无法观察这一过程 ,但离体脑片为我们提供了一个较为理想的研究方法。本实验通过对离体海马脑片进行孵育 ,观察Ｇｌｎ对Ｇｌｕ递质释放的影响 ,从而进一步探讨Ｇｌｎ的中枢作用机制。1　材料与方法(1)人工脑脊液 (ＡＣＳＦ)的配制　所用标准ＡＣＳＦ的配方为 (ｍｍｏｌ/Ｌ) :ＮａＣｌ 12 4,Ｋ…     

日粮添加塞曼特罗（CIM）对大鼠生长胴体组成及GH水平的影响

选用２４只２月龄ＳＤ处女鼠配对分组,实验组日粮添加１０μｇ／ｇ塞曼特罗（ＣＩＭ）,试验期３０天。与对照组比较,ＣＩＭ显著提高大鼠生长速度（２７．３０％,Ｐ＜０．０１）和胴体比率,降低腰胁部脂肪重,提高腓肠肌、比目鱼肌和趾浅屈肌的鲜重和ＲＮＡ合量及ＰＮＡ／ＤＮＡ值,同时提高大鼠垂体和血清ＧＨ水平分别达３６．７０％（Ｐ＜０．０１）和２３．７７％（Ｐ＜０．０５）,降低血清脲氮含量。表明ＣＩＭ可显著促进大鼠生长,降低体脂含量,促进肌肉肥大,促进蛋白沉积。其作用机理可能还与其促进ＧＨ的合成和分泌有关。     

大鼠附睾上皮细胞的识别

本文利用免疫荧光技术,用角蛋白和波形蛋白抗体作为组化探针,对不同年龄大鼠的整体和离体培养的附睾上皮细胞进行鉴定,区分出结缔组织成分。并证明用0.05%胰蛋白酶和0.1%胶原酶相继消化附睾管可得到较丰富的上皮细胞,体外培养能维持10d 以上,在培养过程中显示其形态特征。因此本文所用的分离、培养方法所得到的附睾上皮细胞可作为深入研究其功能的一种模型。     

大鼠前列腺上皮细胞在无血清培养液中增殖的调节

本文报道了未成年大鼠前列腺上皮细胞的无血清培养模型的建立方法,并利用该模型研究了生长因子、催素及性激素对前列腺细胞增殖功能的作用。结果表明：胰岛素、表皮生长因子、转铁蛋白、霍乱霉素和牛垂体提取物对前列腺细胞的增殖有直接的促进作用,糖皮质激素对细胞的增殖无明显影响。催乳素刺激细胞的增值,但与双氢睾酮或雌二醇无协同作用。单独的双氧睾酮或雌二醇对细胞的增殖无显著作用。     

H2O2致WB-F344细胞内活性氧的产生及机理

以双氢罗丹明123（DHR123）作为荧光探针,采用激光共聚焦扫描显微镜研究小剂量（800nmol/L)H2O2诱导大鼠肝卵细胞株WB－F344细胞内活性氧产生的动态变化过程及其机理。结果发现：（1）小剂量H2O2的一次作用可以引起胞内活性氧的产生;（2）胞内活性氧清除剂N－乙酰－L－半胱氨酸（NAC）处理2h时后,再加入小剂量H2O2,发现胞内活性氧的产生明显减少;（3）用广谱的蛋白激酶抑制剂2－氨基嘌呤（2－AP）、Ca^2 依赖性蛋白激酶（PKC）抑制剂Bisindolylmaleimide Ⅰ、酷氨酸蛋白激酶（TPK）抑制剂Tyrphostin25分别预处理15min后,H2O2诱导的胞内活性氧的产生现象均消失;（4）细胞在无外钙环境下,小剂量H2O2诱导的胞内活性氧的产生明显减少;（5）细胞在无外钙环境下用NAC预处理后,H2O2诱导的胞内活性氧的产生现象消失。结果表明,H2O2可以通过胞内信号转导系统诱使WB细胞胞内活性氧产生,这可能与小剂量H2O2调控细胞生物学功能（如增殖、转化）相关。     

EFFECTS OF DEXAMETHASONE ON NEUROTRANSMITTER ENZYMES IN CHROMAFFIN TISSUE OF THE NEWBORN RAT

—Dexamethasone administration to newborn rats resulted in an increase in phenylethanolamine N-methyltransferase activity in superior cervical ganglia. The same treatment resulted in a decrease in tyrosine hydroxylase and choline acetyltransferase activities. The decline in choline acetyltransferase activity after dexamethasone treatment was only seen when the drug was given before 5 days of age. When dexamethasone was given to pregnant rats it caused an age-dependent decrease in choline acetyltransferase in the adrenals, superior cervical ganglia and para-aortic chromaffin tissue of the offspring. These results suggest that dexamethasone administration may delay the development of the preganglionic neurons of sympathetic ganglia. This in turn would delay the development of tyrosine hydroxylase but not phenylethanolamine N-methyltransferase.     

THE DIFFERENTIATING ABILITY OF RAT LENS EPITHELIAL CELLS IN CELL CULTURE

Dissociated cells of lens epithelia of adult rats were monolayerly cultured in vitro. After about 15–20 days' period of active cell growth, such characteristic structures that correspond to "lentoid bodies" described previously in chick cultures were formed. These structures consisted of elongated cells, ultrastructural profile of which was similar with lens fiber. The presence of gamma-crystallin, a marker molecule specific to mature lens fiber, was confirmed in these elongated cells by means of fluorescent antibody technique. The differentiation of lens fiber in vitro was also recognized in clones originating from single lens epithelial cells cultured at very low cell density.     

穹窿切断对大鼠下丘脑CRH表达的影响

目的观察穹窿切断对大鼠下丘脑促肾上腺皮质激素释放激素(CRH)表达的影响,探讨海马对HPA轴的抑制作用是否通过穹窿介导。方法成年健康雄性Wistar大鼠80只,随机分为穹窿切断组和假手术组,再分为0d、4d、7d、10d组,每组10只。建立大鼠穹窿切断模型,采用免疫组织化学和Westernblot技术检测穹窿切断组0d、4d、7d、10d时下丘脑CRH的表达变化和分布规律,并以假手术组相应时间段作为对照。结果穹窿切断组于7d时CRH表达升高,10d时升高显著。假手术组下丘脑仅有少量CRH表达。结论穹窿切断使CRH表达升高,HPA轴活动增强,海马对HPA轴的抑制作用减弱,揭示海马是通过穹窿纤维对HPA轴发挥抑制作用。     

改变食物组成对大鼠胃肠道嗜铬细胞的影响

为研究食物组成对肠嗜铬（ＥＣ）细胞的影响，用免疫组织化学方法（ＰＡＰ法）对４组食物组成不同大鼠的胃肠道５－羟色胺免疫反应阳性（５－ＨＴＩＲ）细胞的数量和分布作了观察。发现食物改变会引起大鼠摄食量和胃肠形态的变化，但未见其生长发育异常。食物中米糠含量加倍后，大鼠５－ＨＴＩＲ细胞数量无显著增加，但分布型有明显的变化。食物中米糠含量或米糠和麦麸含量都减少到１０％后，大鼠５－ＨＴＩＲ细胞数量和分布都有明显     

EFFECTS OF DI-ISOPROPYLFLUOROPHOSPHATE ON THE METABOLISM OF CHOLINE AND PHOSPHATIDYLCHOLINE IN RAT BRAIN

—The subcutaneous administration of 2·0 mg DFP per kg to rats causes a diminution in the lysophosphatidylcholine content in the brain, which is followed by a decrease of glycerylphosphorylcholine concentration and by a reduced post mortem choline increase. This supports the hypothesis that a post mortem increase in choline is due to phosphatidylcholine breakdown. Since the amount of phosphatidylcholine in brains of di-isopropylfluorophosphate-treated rats increases, it is concluded that phospholipase A is inhibited by di-isopropylfluorophosphate, which corresponds to findings of other authors in vitro. The activity of glycerylphosphorylcholine diesterase (EC 3.1.4.2) is not altered.     

窒息对大鼠脊髓诱发电位的影响

实验在筒箭毒制动的麻醉与清醒大鼠上进行。用银球电极记录刺激腓神经引起的脊髓诱发电位,观察其在窒息和窒息后恢复通气过程中的变化。窒息后P波振幅最先降低,N波次之,A波在P、N波消失时下降到前对照的80％左右。窒息3分钟时恢复通气后,按A、N、P波的顺序恢复到前对照水平。窒息及其恢复过程中,不同于A波的变化,N、 P相伴改变。麻醉与清醒状态下,上述变化规律相似。结果提示,有突触活动参与的N波,特别是P波对窒息最敏感,反映初级传入末梢活动的A波对窒息有相当的耐受性。