藥學(xué)英語課本

1、Developing Drugs from TraditionalMedicinal PlantsOver three quarters of the world's population relies mainly on plants and plant extracts for health care Approximately one third of the prescription drugs in the US contain plant components， and more than 120 important prescription drugs are deriv

2、ed from plants Most of these drugs were developed because of their use in traditional medicineEconomically， this represents $800310, 000M of annual consumer spending Recent World Health Organization (WHO) studies indicate that over 30 per cent of the world's plant species have at one time or ano

3、ther been used for medicinal purposes Of the 250， 000 higher plant species on Earth， more than 80， 000 species are medicina l Although traditional medicine is widespread throughout the world， it is an integral part of each individual culture Its practice is based mainly on traditional beliefs handed

4、 down from generation to generation for hundreds or even thousands of yea rsUnfortunately， much of this ancient knowledge and many valuable plants are being lost at an alarming ra teThe scientific study of traditional medicines and the systematic preservation of medicinal plants are thus of great im

5、portanceFor quite a long time， the only way to use plant medicines was either direct application or the use of crude plant extracts With the development of organic chemistry at the beginning of this century， extraction and fractionation techniques improved significantly It became possible to isolate

6、 and identify many of the active chemicals from plants In the 1940s， advances in chemical synthesis enabled the synthesis of many plant components and their derivativ esIn western countries， it was thought that chemical synthesis of drugs would be more effective and economical than isolation from na

7、tural sources Indeed， this is true in many cases However， in many other cases， synthetic analogues are not as effective as their natural counterpartsIn additio， some synthetic drugs cost many times more than natural one s Inspired by these realisation，s coupled with the fact that many drugs with com

8、plex structures may be totally impossible to synthes，is there is now a resurgent trend of returning to natural resources for drug developmentImportant prescription drugs from plantsEphedrine is the oldest and most classic example of a prescription drug developed from a traditional medicinal plant It

9、 is derived from Ma Huang， a leafless shrub Used to relieve asthma and hay fever in China for over 5000 years， it was introduced into western medicine in 1924 by Chen and Schmidt Ephedrine is an alkaloid closely related to adrenalin，e the major product of the adrenal gland Pharmacologically， Ephedri

10、ne is used extensively to stimulate increased activity of the sympathetic nervous system It is used as a pressor agent to counteract hypotension associated with anaesthesia， and as a nasal decongestantThe drug action of this medicine is based both on its direct effect on a and 0 adrenergic receptors

11、 and on the release of endogenous noradrenalineDigitalis is one of the most frequently used medications in the treatment of heart failure and arrhythmia It increases the contractility of the heart muscle and modifies vascular resistance It also slows conduction through the atrioventricular node in t

12、he hea，rt making it useful in the treatment of atrial fibrillation and other rapid heart rhythmsDigitalis is found in the leaves and seeds of Digitalis purpurea and Digitalis lanat，a commonly known as the foxglove plantFoxglove has been used in traditional medicine in manyparts of the world-by Afric

13、an natives as arrow poisons， by the ancient Egyptians as heart medicine，and by the Romans as a diureti，c heart tonic，emetic and rat poisonTheChinese， who found this ingredient not only in plants but also in the dry skin and venom of the common toad， used it for centuries as a cardiac dru g In the we

14、stern world， the foxglove was first mentioned in 1250 in the writing of a physician，Walsh， and it was described botanically in the1500sDigitalis is a glycoside containing an aglycone， or genin， linked to between one and four sugar molecules The pharmacological activity resides in the aglycone， where

15、as the sugar residues affect the solubility and potency of the drug The aglycone is structurally related to bile acids， sterols， sex hormones and adrenocortical hormone sd-Tubocurarine and its derivatives are the most frequently used drugs in operating rooms to provide muscle relaxation and prevent

16、muscle spasm These agents interrupt the transmission of the nerve impulse at the skeletal neuromuscular junction Curare，the common name for SouthAmerican arrow poisons，has a long and interesting historyIt has been used for centuries byIndians along the Amazon and Orinoco rivers for huntingIt causes

17、paralysis of the skeletalmuscles of animals and finally results in death The methods of curare preparation were a secret entrusted only to tribal doctors Soon after their discovery of the American continen，t European explorers became interested in curar e In the late 16th century， samples of native

18、preparations were brought to Europe for investigationCurare， an alkaloid， was found in various species of Strychnos and certain species of Chondrodendron The first use of curare for muscle relaxation was reported in 1942 by Griffith and Johnson This drug offers optimal muscular relaxation without th

19、e use of high doses of anaesthetics It thus emerged as the chief drug for use in tracheal intubation and during surge ryVinblastine and Vincristine are two of the most potent antitumour drugs They are obtained from Catharanthus roseu，s commonly known as the rosy periwinkle This plant， indigenous to

20、Madagascar， is also cultivated in India，Israel and the US It was originally examined for clinicaluse because of its traditional use in treating diabete sThe leaves and roots of this plant contain more than 100 alkaloids Fractionation of these extracts yields four active alkaloids： Vinblastine， Vincr

21、istine， Vinleurosine and Vinresidine These alkaloids are asymmetric dimeric compounds referred to as vinca alkaloids，but of these， only Vinblastine and Vincristine are clinicallyimportant antitumour agents These two alkaloids are cell-cycle specific agents that block mitosis (cell division) Vincrist

22、ine sulphate is used to treat acute leukaemia in children and lymphocytic leukaemia It is also effective against Wilm's tumour， neuroblastoma， rhabdomyosarcoma (tumour of voluntary or striped muscle cells)， reticulum cell sarcoma and Hodgkin's disease Vinblastine sulphate is used in the trea

23、tment of Hodgkin's diseas， e lymphosarcoma， choriocarcinoma， neuroblastoma， carcinoma of breas，t lung and other organs， and in acute and chronic leukaemiaEmerging plant medicinesArtemisinin is the most recent anti-malaria drug developed from plant-based traditional medicineIt is isolated from th

24、e leaves and flowers of Artemisia annua L (Compositae)，commonly known as the sweet wormwood，a cousin of tarragon Indigenous to China， theextract of this plant is traditionally known as the QinghaoIt has been used to treat malaria inChina for over 2000 years Its active component， Artemisinin ， was fi

25、rst isolated in the 1970s by Chinese scientists Unlike Quinine and Chloroquine， this compound is non-toxic rapid in effect， and safe for pregnant women Furthermore， it is effective against chloroquine-resistant Plasmodium falciparum malaria and in patients with cerebral malaria It kills the parasite

26、s directly so parasitemia is quickly controlled This work was confirmed by the WHO in Africa and other parts of Southeast AsiaArtemisinin is an endoperoxide of the sesquiterpene lactone The structure of this compound is too complex to be synthesised effectively Artemisia is also found in many parts

27、of the US ， abundantly along the Potomac River in Washington DC ， but the drug content of these varieties is only about half that of the Chinese variety Currently ， the WHO and the US are jointly engaged in the cultivation of Chinese Artemisia for worldwide use This recent development offers renewed

28、 hope for using traditional medicine to provide new drugs for future medicines 1 .prescription n.處方，藥方，規(guī)定2 .World Health Organization 世界衛(wèi)生組織（縮寫為WHO）3 .adrenergic a 腎上腺素的，類似腎上腺素的，釋放腎上腺素的4 .Artemisinin 青蒿素5 .antimalaria n. 抗瘧疾，防瘧疾6 .fractionation n 分餾7 .counterpart n 配對物，副本，極相似的人或物8 .resurgent a 復(fù)活的，蘇

29、醒的，恢復(fù)活力的9 .asthma n 哮喘10 .adrenal n.腎上腺；a.腎上腺的11 .gland n. 腺12 .pharmacologically ad.藥理地，藥學(xué)地，藥用地13 .pressor n.升高血壓的物質(zhì)a.有使血壓增高的，收縮血管的14 .hypotension n. 低血壓15 .anaesthesia n 麻醉（法 ），感覺缺乏，麻木16 .nasal a 鼻的，護(hù)鼻的，鼻音的n 鼻音，鼻音宇17 .endogenous a. 內(nèi)生的，內(nèi)長的18 .noradrenalinen. =norepinephrine 去甲腎上腺素19 .digitalis n 洋

30、地黃20 .arrhythmia n 心律不齊21 .contractility n.收縮性，縮小性，伸縮力22 .vascular a.脈管的，血管的，有脈管的23 .atrioventricular a 房室的，心房與心室的24 .node n.結(jié)25 .atriala 心房的，有關(guān)心房的26 .fibrillationn 纖維性顫動(dòng)27 .Digitalis purpurea 紫花毛地黃28 .Digitalis lanata 毛花洋地黃29 .foxglove n.毛地黃30 .diuretic n.利尿劑；a.利尿的31 .a heart tonic 強(qiáng)心藥32 .venom n.毒

31、液33 .toad n.蟾蛛，癩蛤蟆34 .cardiac n.強(qiáng)心劑，強(qiáng)胃齊1J ; a.心臟的，（胃的）賁門的35 .botanically ad.植物（學(xué)）地36 .glycoside n 苷，配糖類，配糖物37 .aglycone n 配質(zhì)，配基，（苷的）非糖部38 .genin n 配質(zhì)，配基39 .solubility n 溶 （解 ）度，溶（解 ）性，（可 ）溶性40.potency n 效力，效驗(yàn)，能力，潛力，力量41.bile acid 膽汁酸42.sterol n.番醇，固醇43.sex hormone 性激素44 .adrenocortical hormone n 腎上腺

32、皮質(zhì)激素45 .digoxigenin n 異羥基洋地黃毒苷，地谷新配質(zhì)46 .digitoxigenin n.毛地黃毒甘配基，戶（丁烯酸內(nèi)酯）-14-羥番醇47 .d-tubocurarine n. d-管箭毒堿48 .relaxation n,松弛，緩和，減輕，放寬49 .spasm n.痙攣，一陣發(fā)作50 .skeletal a.骨骼的，骸骨的51 .neuromuscular a.神經(jīng)肌肉的52 .curare n.箭毒，馬錢子屬植物，馬錢子（也叫番木鱉）53 .paralysis n.癱瘓，麻痹54 .entrusted vt.委托，托管，信托55 .Strychnosn S- 馬錢

33、子屬，毒鼠堿56 .Chondrodendron n.南美防己屬57 .tracheal a 氣管的，導(dǎo)管的，呼吸管的1.1 intubation n.插管，插管法59 .Vinblastine n 長春堿60 .Vincristine n.長春新堿61 .antitumour n.抗癌的，抗月中瘤的62 .Catharanthus roseus 長春花63 .periwinkle n.長春花屬的植物，玉黍螺1.1 indigenous a.本土的65 .Madagascar n.馬達(dá)加斯加島(非洲島國)66 .diabetes n 糖尿病，多尿癥67 .Vinleurosine n 環(huán)氧長春

34、堿68 .Vinresidine n. ( = leurosidine) 異長春堿，洛諾西 169 .asymmetric a.不對稱的，不均勻的70 .dimeric a.二聚的，形成二聚物的71 .vinca n 長春花72 .Vincristine sulphate 硫酸長春新堿73 .acute a.急性的，敏銳的74 .chronic a.慢性的，延續(xù)很長的74.1 eukaemia n 白血病76.lymphocytic a.淋巴球的，淋巴細(xì)胞的77.neuroblastoma n.成神經(jīng)細(xì)胞瘤78.rhabdomyosarcoma n 橫紋肌肉瘤79.striped n.有斑紋的

35、80.sarcoma n 肉瘤，惡性毒瘤1.1 lymphosarcoma n. 淋巴肉瘤82 .choriocarcinoma n 絨膜癌83 .carcinoma (復(fù)carcinomas或 carcinomata) n.癌84 .anti-malaria n.抗瘧疾85 .Artemisia annua L 黃花蒿屑植物，青蒿屬植物86 .Compositae n.菊科87 .wormwood n 蒿屬植物88 .tarragon n 龍蒿，龍蒿葉89 .malaria n.瘧疾，瘴氣90 .Quinine n.奎寧91 .Chloroquine n.氯唾92 .Plasmodium f

36、alciparum 惡性瘧原蟲，鐮狀瘧原蟲93 .cerebral a.腦的，大腦的 94.parasite n.寄生蟲，食客 95.parasitemia n.寄生蟲血癥96 .endoperoxide n 橋過氧化物97 .sesquiterpene n.倍平菇烯98.lactone n.內(nèi)酯The Autonomic and CentralNervous Systems( I )All chemical substances that have a potential for abuse produce their desirable (and often undesirable) ef

37、fects by mechanisms involving the nervous system. To understand how abused substances produce their sought-after effects and why various modalities are used to treat their toxic manifestations, a basic knowledge of the structure and function of the nervous system is necessary. The following overview

38、 presents the major components of the nervous system and their functions. This information is not intended as a comprehensive review of neuroanatomy, but rather as a basis for understanding the drug-related material to be presented in later chapters in this text. Additional information may be obtain

39、ed from the references and selected readings listed at the end of this chapter.Anatomically, the nervous system is divided into two major components: the central nervous system(CNS) and theperipheral nervous system. The CNS, composed of the brain and spinal cord, is responsible for integrative funct

40、ions related to both conscious and subconscious activities of the body. It is also ultimately responsible for the interpretation of, and reaction to, all information that the body receives from the environment. The peripheralnervous system is made up of nerve fibers that conduct information toward t

41、he CNS (afferent fibers) and nerve fibers that conduct directives from the CNS to all body areas (efferent fibers). Before undertaking a general discussion of the nervous system, a brief review of the basic unit of the nervous system, the neuron, and the mechanisms by which information is transferre

42、d throughout the nervous system is in order.The NeuronThe neuron, or nerve cell, is the base of all activities of the nervous system. Neurons differ from other body cells in two respects: 1() they can conduct information in the form of electrical impulses over long distances; and (2) they relate to

43、other nerve cells and innervated tissue in a highly specialized manner. The neuron consists of a cell body, anaxon, which carries information away from the cell body, and one or moredendrites, which carry information toward the cell body. Some axons are surrounded by a layer of fatty tissue called a

44、myelin sheath, which develops within the nervous system over a period of years and serves as a protective coating.The ability of the neuron to transmit information from one site to another is a function of its electrical transmission capability and its capacity to synthesize, store, and release high

45、ly specific chemicalsne( urotransmitters) from nerve endings. The site where two nerve endings meet or where a nerve meets the tissue that it innervates is a small gap that is termed thseynapse, or synaptic cleft. In order for electrical impulses to cross a synapse, a neurotransmitter is released fr

46、om one nerve ending to travel across the synapse and stimulate receptors on an adjacent nerve or tissue.The Peripheral Nervous SystemThe peripheral nervous systemconsists of all the nerve fibers that conduct information to and from the CNS and that lie outside the brain and spinal cord. Peripheral a

47、fferent fibers are involved with sensations such as pain, temperature, and touch, whereas peripheral efferent fibers are involved with the control of specific body functions. Efferent fibers are divided into two categories: (1) somatic fibers, which control the function of skeletal muscle, and (2) a

48、utonomic fibers, which control the activities of smooth muscle, cardiac muscle, and glands of excretion.Somatic nerve fibers leave the spinal cord at various levels, depending on the location of the innervated skeletal muscle, and continue as an uninterrupted unit from their site of origin (motor ne

49、uron) to skeletal muscle tissue. The site at which the somatic fiber meets the skeletal muscle is termed theneuromuscular junction (NMJ). The neurotransmitter at the NMJ is acetylcholine.Autonomic efferent fibers control the automatic or subconscious functioning of smooth and cardiac muscle and exoc

50、rine glands. These fibers are responsible for activities such as the maintenance of tone in the gastrointesitinal tract and blood vessels, regulation of heart rate and release of substances such as saliva, respiratory secretions, and gastric acidA. utonomic fiber tracts actually consist of two separ

51、ate fibers. The first fiber (presynaptic fiber) originates inside the spinal cord and terminates at a synapse somewhere in the periphery. The second fiber (postsynaptic fiber) originates at the synapse and terminates at the innervated tissue.In most instances, the synapses of a number of fibers are

52、grouped together and termedganglion. In such cases, the presynaptic and postsynaptic fibers are referred to as preganglionic and postglanglionic fibers, respectively. The site at which the postganglionic fiber synapses with the innervated tissue is termed the neuroeffector junction (NEJ).Autonomic f

53、ibers are categorized by two methods. The first and older method of classification is based on the sites at which preganglionic fibers leave the CNS. Nerves that exit from the thoracic and lumbar levels of the spinal cord are termedsympathetic, whereas those that exit from the sacral level of the sp

54、inal cord and cranium are termedparasympathetic.The second method of classification is based on the neurotransmitter released at the NEJ by the nerve fiber. Nerves that release acetylcholine (Ach) are termedcholinergic, whereas those that release norepinephrine (NE) are termedadrenergic. In general,

55、 the termsympatheticis interchangeable with adrenergic and the termparasympatheticis interchangeable with cholinergic. Cholinergic and adrenergic are usually the preferred terms when discussing drug effects on autonomic function because they designate the specific neurotransmitters affected by the d

56、rugs.Within the autonomic nervous system(ANS), receptor sites for Ach and NE have a very specific nomenclature based upon their location and function. Cholinergic receptor sites are found in the ganglionic synapses of both the sympathetic and parasympathetic nervous system. They are also found at th

57、e NEJ of parasympathetic fibers. Cholinergic receptor sites are categorized as being either muscarinic or nicotinic, based on whether they respond to the alkaloids muscarine or nicotine, respectively. Muscarinic receptors are found at the parasympathetic NEJ. Nicotinic receptors are found at all aut

58、onomic ganglia and at the somatic NMJ.Adrenergic receptor sites in the ANS are found only at the sympathetic NEJ. Adrenergic receptors are divided into three categoriesa: lpha, beta1, and beta2.In general, stimulation of the alpha adrenergic receptor site causesan increase in activity of the innervated tissue. Alpha receptors are found primarily in arterioles and therefore are important in the maintenance of blood pressure. Stimulation of alpha receptors by NE leads to arteriolar constriction, which increases blood pressure. B