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首页> 外文期刊>The Internet Journal of Toxicology >Histoenzymic Effects Of Cigarette Smoke On The Superior Colliculus Of Rattus Norvegicus.
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Histoenzymic Effects Of Cigarette Smoke On The Superior Colliculus Of Rattus Norvegicus.

机译：香烟烟雾对褐家鼠上皮囊的组织酶学影响。

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The study was conducted using twenty adult Wistar rats that were randomly grouped into a treatment and a control group comprising both sexes. The control group was exposed to smoke from cotton wool, while the treatment group inhaled smoke from a completely burnt cigarette containing 0.735 g tobacco, once daily for 14 days. The rats were sacrificed by cervical dislocation and the superior colliculi (SC) excised, weighed, homogenized and assayed for the activities of lactate dehydrogenase (LDH), glucose-6-phosphate dehydrogenase (G6PDH), and alkaline phosphatase (ALP). SC tissues for histological studies were fixed in formol calcium and subsequently processed using Feulgen reaction for nucleic acids and Cresyl violet stain for Nissl bodies studies. There was an increase in the enzyme activities in the treated group, compared to the control; and this increase was more in the female rats although not statistically significant. The derangements observed in the enzyme studies led to various histoarchitectural changes in the SC of the rats exposed to tobacco smoke, and a gradual depletion of DNA positive cells and Nissl bodies in the neurons. Introduction Many of the 4 000 constituents of tobacco smoke are known to be toxic to the body, affecting the brain, cardiovascular and respiratory systems, among other systems and organs of the body1. Many of these components are volatilized during burning, and others, including the aromatic hydrocarbons, are formed during combustion of the leaf components 2. By virtue of the short-term actions of nicotine on the cholinergic system, it has positive effects on certain cognitive domains, and has been said to be neuroprotective in a way3. The chief pharmacologically active ingredients are nicotine (acute effects) and tar (chronic effects) 4. A completely burned cigarette stick usually contains between 1-6 mg of nicotine, apart from the 1-5 % carbon monoxide present in the smoke 5.The superior colliculus (SC) functions in visual attention and centering of the visual image on the retina, thereby serving essentially as a visual relay centre6. It transforms both visual and non-visual sensory signals into motor commands that control orienting behaviors7. Studies by Yildiz et al 8 showed that nicotine is capable of modulating enzyme activities. Vascular injury resulting from ischemic process leads to reduction in the supply of oxygen and nutrients to the brain, thereby causing various forms of degenerative changes in the tissue.Tobacco smoke, as an exogenous source of reactive oxygen species, has a broad spectrum of oxidant-ionising radiation which generates free radicals in exposed tissues9. Due to a low oxygen tension, anaerobic glycolytic pathway is utilized to supply the brain with its ATP requirement. The conversion of lactate to pyruvate is catalyzed by lactate dehydrogenase (LDH). Following nicotine administration, LDH leakage through the membranes is elevated, due to its effects on some membrane markers, thereby increasing the level of this enzyme 8,10.Glucose-6-phosphate dehydrogenase (G-6-PDH) is important in the production of reduced nicotinamide adenine dinucleotide phosphate (NADPH) and the production of ribose, which are vital in RNA and DNA replication11. Alkaline phosphatase (ALP), a membrane marker, facilitates transport across cell membranes, causing the breakdown of ATP to ADP and inorganic phosphate, thereby making free energy available for metabolic processes12. The present work was designed to study the effect of nicotine on the morphology of the superior colliculus (especially in relation to DNA and Nissl bodies) and certain enzymes of glucose metabolism in a model of Wistar rats. Materials and Methods Following appropriate ethical guidelines, twenty (20) adult Wistar rats of both sexes with an average weight of 219.5 g were randomly divided into a control and a treated group. They were allowed to acclimatize, and housed in different cages at normal room temperature, at the Anatom
机译：这项研究是使用20只成年Wistar大鼠进行的，这些大鼠被随机分为治疗组和对照组（包括两性）。对照组暴露于纯棉烟雾中，而治疗组则每天吸入一次完全燃烧的香烟，其中香烟中含有0.735 g的烟，持续14天。通过颈脱位法处死大鼠，切除上肢结肠（SC），称重，均质化，并测定乳酸脱氢酶（LDH），葡萄糖6-磷酸脱氢酶（G6PDH）和碱性磷酸酶（ALP）的活性。将用于组织学研究的SC组织固定在甲醛酚钙中，随后使用Feulgen反应处理核酸，并使用Cresyl紫染色处理Nissl身体。与对照组相比，治疗组的酶活性有所增加。而且这种增加在雌性大鼠中更大，尽管没有统计学意义。在酶研究中观察到的紊乱导致暴露于烟草烟雾的大鼠的SC发生各种组织结构变化，并逐渐耗尽神经元中的DNA阳性细胞和Nissl体。简介众所周知，烟草烟雾的4000种成分中有许多对身体有毒，会影响大脑，心血管和呼吸系统以及身体其他系统和器官1。这些成分中的许多成分在燃烧过程中会挥发，而其他成分（包括芳香烃）在叶片成分燃烧过程中会形成2。由于尼古丁对胆碱能系统的短期作用，它对某些认知域具有积极作用，据说在某种程度上具有神经保护作用。主要的药理活性成分是尼古丁（急性作用）和焦油（慢性作用）4。完全燃烧的香烟棒通常含有1-6毫克的尼古丁，除了烟雾中存在的1-5％一氧化碳5。上丘（SC）在视觉注意力和视网膜上的视觉图像居中功能中发挥作用，从而基本上充当视觉中继中心6。它将视觉和非视觉的感觉信号转换为控制定向行为的运动命令。 Yildiz等[8]的研究表明，尼古丁能够调节酶的活性。缺血过程导致的血管损伤导致大脑供氧和养分供应减少，从而导致组织中各种形式的变性变化。作为活性氧的外源来源，烟草烟雾具有广泛的氧化剂-在暴露的组织中产生自由基的电离辐射9。由于低氧张力，厌氧糖酵解途径被用于为大脑提供其ATP需求。乳酸脱氢酶（LDH）催化乳酸向丙酮酸的转化。尼古丁给药后，由于其对某些膜标记物的影响，LDH通过膜的泄漏增加，从而增加了该酶8,10的水平。6-磷酸葡萄糖脱氢酶（G-6-PDH）在生产中很重要还原的烟酰胺腺嘌呤二核苷酸磷酸（NADPH）和核糖的产生，这对RNA和DNA复制至关重要。碱性磷酸酶（ALP）是一种膜标记物，有助于跨细胞膜的运输，导致ATP分解为ADP和无机磷酸盐，从而使自由能可用于代谢过程12。本工作旨在研究烟碱对Wistar大鼠模型中上丘形态（特别是与DNA和Nissl体有关）和某些葡萄糖代谢酶的影响。材料和方法按照适当的道德准则，将二十（20）只平均体重为219.5 g的雌雄成年Wistar大鼠随机分为对照组和治疗组。使它们适应环境，并在正常室温下在Anatom的不同笼子中

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