Receptors in Intestinal Muscles

Receptors in Intestinal Muscles The experiment was conducted in order to gain better understanding of the function of the receptors in the guinea pig ileum. For this reason, various agonists and antagonists were used and the muscle reaction was monitored. The results of our experiment are summarized in the following table. As we can see acetylcholine and hexamethonium both have a triethylamine at one end and a straight chain of carbons. The basic difference is that hexamethonium has two tertiary amines, one on each end of the chain, whereas acetylcholine has the group -O-C(=O)-CH3 on one end. According to the SAR theory (Structure Activity Relationship) similar molecules in structure tend to have similar biological activity. As we know, both acetylcholine and hexamethonium bind to the nicotinic receptor, the first one to trigger a response and the second one to prevent acetylcholine from binding. Hexamethonium, having two active groups, can probably bind more easily to the receptor, effectively blocking the acetylcholine action. b) Histamine and mepyramine have less similarities in structure. Both of them have three nitrogen and an aromatic ring. Histamine has the two nitrogen inside the aromatic ring whereas mepyramine has only one nitrogen bound in the ring. Both compounds bind to the H1-Histamine receptor, to trigger different reactions. The difference in structure can be explained by the different action of the two compounds. Histamine causes contraction of the muscle and mepyramine causes its relaxation. The drugs tested were classified as agonists and antagonists. Acetylcholine: Acts as neurotransmitter. It binds on the muscarinic and nicotinic receptors and causes muscle contraction. Histamine: Is also a neurotransmitter. It binds on the H1-Histamine receptor and causes smooth muscle contraction. Nicotine: It acts on the nicotinic cholinergic receptors and mimics the neural transmission. It stimulates the muscle, then blocks stimulation. Isoprenaline: Although isoprenaline was apparently an antagonist, it is actually a selective agonist for the ÃŽÂ ²- adrenergic receptors that causes muscle relaxation. It is a sympathomimetic drug that mimics the effect of stimulating the postganglionic adrenergic sympathetic nerves. Hexamethonium: It is a nicotinic antagonist and a ganglionic blocker. It binds to the nicotinic cholinergic receptors and blocks the actions of acetylcholine or cholinergic agonists. It has no effects on muscarinic (mAch) receptors. Mepyramine: It is a histamine H1 antagonist and targets the H1- Receptor. Although it was believed to be an antagonist merely to block the actions of endogenous histamine without activating the receptors, it has recently been classified as an inverse agonist decreasing the spontaneous activity of gp-H1r. It also inhibits histamine induced inositol phosphate (InsP) production and intracellular calcium mobilization. It causes a marked decrease in the maximal response to histamine at high concentrations. Atropine: It is a competitive antagonist for the muscarinic cholinergic receptor (mAch). It binds to the receptor without activating it, thus blocking the actions of endogenous acetylcholine or exogenous agonists. a) The drug in this experiment were acting on three receptors. H1-Histamine receptors, muscarinic (mAch) receptors and nicotinic (nAch) receptors. Each agonist was acting on a different receptor and that is apparent from our results. When using an antagonist that blocked a specific receptor it only inhibited the action of the drug acting on that particular receptor, and had no effect on the rest of the drugs. b) The receptors were obviously located on the surface of the muscle, so that the access of the drugs would be possible. The first apparent antagonist which turned out to be an agonist was isoprenaline. It acts on the ÃŽÂ ²- adrenergic receptors causing muscle relaxation and antagonized all the three agonists who acted on different receptors. This type of antagonism is called a physiological antagonist and describes the interaction of two drugs who cause opposing actions in the body and tend to cancel each other. In this case, the isoprenaline acts on the ÃŽÂ ²- adrenergic receptors and causes relaxation of the muscle, whereas the agonist act on the histaminic, nicotinic and muscarinic receptors and cause contraction of the muscle. The second apparent antagonist was mepyramine, which acts on the histamine receptor and blocks the action of histamine. It has recently been classified as an inverse agonist, causing muscle relaxation. This type of agonists show selectivity to the resting state of the receptor. Atropine acts on the muscarinic receptors and blocks their action. Thus it prevents acetylcholine from binding to the receptor and stimulating it. Nicotine though activates the nicotinic receptor that apparently has nothing to do with atropine. The reversal of nicotine action indicates the presence of inhibitory postganglionic (terminal) neurones, which respond to stimulation of their ganglion-cells by inducing relaxation of the gut. It is also suggested by other experiments [Phillis York, 1968] that an intermediate type of receptor is involved. Assuming specificity of the antagonist these studies are explained by a non-classical cholinergic receptor with mixed pharmacological properties. Such receptors are the newest members of the nicotinic acetylcholine receptor (nAChR) family, encoded by the ÃŽÂ ±9/ÃŽÂ ±10 subunits, that possess a combined nicotinic-muscarinic sensitivity. Barium Chloride is a water soluble salt. Once in contact with the muscle it induces release of intracellular stores of calcium, and causes the contraction of the muscle. If barium chloride comes in contact with sodium sulphate it loses its potency. That is explained by the chemical reaction between the two compounds. Molecular equation: BaCl2(aq) + Na2SO4(aq)> BaSO4(s) + 2NaCl(aq) ionic equation: Ba+2(aq) + 2Cl-(aq) + 2Na+(aq) + SO4-2(aq) > BaSO4(s) + 2Na+(aq)+2Cl-(aq) These reactions show that once in contact with sodium sulphate, the barium chloride dissolves into BaSO4 which is an insoluble substance and NaCl. Thus, it can no longer act on the muscle. That type of antagonism is called Chemical Antagonism and it refers to the situation when two substances combine in solution; as a result, the effect of the active drug (in this case the barium chloride) is lost. The drugs were tested on guinea pig ileum which is a smooth muscle.

Ermo Essay

Ermo, directed by Zhou Xiaowen in 1994, takes place in the 1980’s when China first began to actively accept the concept of globalization. â€Å"Ermo, where the title character as the strong-willed wife of an emasculated husband† (Tang 654), explores the issues of being a matriarch as well as an individual with her own interests and desires. Compared with traditional Chinese women who were relegated to taking care of the household, Ermo is drastically different because she is the one who attends to the financial needs of her family by selling twisty noodles. Although she is a poor, peasant woman whose life revolves around the responsibilities of taking care of of her family, Ermo harbors secret ambitions which she longs to someday achieve. Fueled by her ambitions, Ermo works day and night to fulfill her aims even as she attends to her loved one’s needs. Her characteristic as responsible matriarch can also be seen when she risks her health by selling large quantities of her blood in order to earn quick money. In the film, every action that Ermo takes is a result of her free will; she is not forced or coerced to do so. Everything that she does, she does for the love of her family. The female lead in the movie is willing to do anything to support her family, which is a marked characteristic of contemporary Chinese films. The role of Ermo is a strong departure from the traditional roles of women in Chinese society. Ermo’s profession is examined in two ways: Noodle seller during the day and noodle maker during the night. In the very beginning of the film, the shot shows her as a noodle-seller on the street, peddling bunches of twisty noodles that she herself made. She yells â€Å"mai mahua mian lou† (twisty noodle for sale) (Ciecko 2) constantly. This scene particularly emphasizes her profession and skills for selling twisty noodles. There are also several close-up shots of her foot while she is making noodle dough. Ermo kneads flour with her feet, and she does it expertly, never dropping any of flour. This shot makes a statement as to the technical skills her work requires and the passion and dedication with which Ermo does her job. While generally regarded as a lowly job, it is actually a very demanding job requiring sophisticated skills. The opportunity to pursue a rewarding career among Chinese women is a fairly recent development because the women in China never had the opportunity to choose their job. Ermo’s desire can be read in various ways: desire for a better life, desire for a fulfilling sexual relationship, and desire for self-determination. Ermo’s â€Å"wish for a new life with a [Blindman, the richest guy in the town] after an amorous night halfway between town and village, expresses her desire to desire and constitutes an inspired revision of reality† (Tang, 668). This satisfies both her sexual desire and desire for better life. She also desires for having the biggest TV in her town, which at first may seem materialistic, but may actually be construed for her need to achieve and be acknowledged for her accomplishments. Although she says that she needs to buy the TV for her son so that he does not have to go to their neighbor’s house to watch, it is really her own aspiration to show people who she really is. Based on strong Confucian society, Chinese women have been traditionally relegated to the sidelines, but as China begins to open itself to changes, so do Chinese women begin to evolve and come out into their own. As examined above, â€Å"the central events in Ermo reflect a new stage in the development of contemporary Chinese society† (Tang, 663). As portrayed in this modern Chinese film, women are able to attend to their family without necessarily having to sacrifice their own dreams and ambitions in the process.

Liberal and Conservative View About the Role of Government

As long as there have been politics in the United States, there has been a productive tension between liberal views and conservative views. These differences are most clearly demonstrated by the disparate views on subjects such as education, taxes and public health care. Liberals and conservatives have different views about the role of government. While liberals; currently represented by the Democratic Party; and conservatives; currently represented by the Republican Party; both believe that education, tax policy, and public health are important issues for the United States; they have different beliefs about the best approach for these policies. Liberals tend towards policies that empower the central government through large all encompassing programs. On the other hand, conservatives prefer locally run programs that are not the same in all communities but may produce results more consistent with community preferences. Currently, no topic provides a better example of the difference between conservatives and liberals than education policy. The liberal belief is that education policy is best when dictated from Washington D. C. with federal education subsidies contingent upon state and local government compliance with federal mandates. Conservatives believe that federal money should not be based on specific agendas developed in Washington D. C. but instead should be granted to state and local governments in the form of grants. These grants do not have strings attached and can be used for state and local education priorities. Conservatives and Liberals also disagree about where education dollars should be spent. The liberal view is that children should go to public schools regardless of quality, they believe that public education efforts and money should be directed towards public schools. Conversely, conservatives believe that children in non-performing schools should have the option to go to private school at public expense. Their view is that competition between public and private schools will improve both. Nobody likes tax time. Liberals and Conservatives both agree that taxes are unavoidable. Their beliefs about the use of taxes and tax policy are very different, though. Liberals seem to believe that taxes are a federal entitlement. They believe that tax money should be spent by the government on large government programs that provide services to people instead of by the taxpayer themselves. Furthermore, liberals believe that tax policy should be used to provide wealth distribution from the rich to the poor. This is most clearly demonstrated by the Earned Income Credit (EIC); the EIC is a tax provision that allows people to receive more in tax refunds than were paid in actual taxes. Conservatives on the other hand truly view taxes as a tool to provide for the common good; they differ from liberals in their approach. They believe that free market forces can more efficiently run large programs than the government can. They believe that large government programs are not inherently productive and taxpayers should be given wide latitude about the use of their money for services that directly affect them. Healthcare is another area where conservatives and liberals find very little common ground. Both sides agree that everyone needs health care, but they disagree what the government†s responsibility should be. Liberals believe that it is the government†s responsibility to provide cradle to grave health care. They believe this should be provided by government regulated quasi-HMO organizations funded by tax dollars. Conservatives think that the government has limited health care responsibility. They believe that the government should provide tax incentives to people so they can buy their health insurance; additionally, they believe that the government should provide limited health care to the poor and the aged. Two statements can best sum up the differences between conservatives and liberals. Conservatives believe in limited government and that government†s responsibility is to create an economy and environment where people can earn decent wages thereby making them self-sufficient. Liberals believe government†s responsibility is to provide for the people and conversely, the people should provide for the government. The truly interesting thing is that the extreme conservatism or fascism and extreme liberalism or communism, have both fallen into disfavor in the last few decades. I believe that this country was founded on conservative principles. Conservatives and liberals have very different views about the way this country should be run and the role of government, which everyone should listen to carefully.

The Poverty Of The United States - 1755 Words

Poverty can be defined as a condition that people suffer from due to lack of economic resources. For being such a prosperous country, the United States possesses a persistent problem. The problem is the poverty rate in America and how it has become a force that continuously grows. One fact that American citizens are not aware of or do not wish to implement in their minds is that nearly 50 million people in the United States live in poverty. Amongst the 50 million people in the United States that live below the poverty line, over 5 million more were women than man. This phenomenon as to in which women experience poverty at far higher rates than men is described as feminization of poverty, a term coined by Diana Pearce in 1978 (3: Thibos).†¦show more content†¦One of his main arguments was that federal welfare became so generous that it led to women preferring unwed motherhood and indolence over getting married and obtaining jobs (315: Edin and Lein). An associate professor of sociology at the University of Pennsylvania, Kathryn Edin, teamed up with Laura Lein, a senior lecturer at the University of Texas at Austin, in order to express whether the benefits of living off the welfare program in the United States actually enabled single mothers to make ends meet. Edin and Lein conducted a study by interviewing 379 single mothers in Boston, Charleston, Chicago, and San Antonio and displayed their studies in â€Å"Making Ends Meet: How Single Mothers Survive on a Welfare Check†. Amongst these single mothers, 214 were welfare-reliant mothers and they were the people that Edin and Lein focused on in order to test the assumption of whether the welfare system was being abused or not. All 214 of these women and their 464 children relied on the Aid to Families with Dependent Children (AFDC), the government income transfer program for poor families that consisted of non-elders. On average these single mothers spent $213 a month on housing, $262 on food, $336 on other necessary expenses, and $64 on items that were not necessarily essential. This summed up to be a total of $876 being spent on an average family of 3.17 people. Although the money they were receiving was helping them reach their goal of