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back to index for this issue CivAb index previous page Two responses to letter in the journal Nature The original letter as it appeared in Nature 431, 125 09, September 2004: Complexity of the body calls for animal research Sir - The criticism of the UK animal regulatory system by Dan Lyons in Correspondence ("The animal-care regulatory system is a sham", Nature 430, 399; 2004) calls for a response. Currently in my fiftieth year of pharmaceutical research, I find it depressing to realize how many legislators and citizens accept the unsupportable position of the animal activists regarding the need for animals in biomedical research. Why can we not get this message across to our citizens and legislators? Where is the activists' protocol for discovering a new drug without using animals? Should they not be required to detail a programme in which animals will not be used? Response #1 Charles Smith (Correspondence, September 9) fails to see the irony that his defense of animal experimentation (complexity) is a perfect explanation for why the very concept is doomed to failure. An intact animal body is indeed unbelievably complex - and differs crucially from an intact body of another species in a complex, non-linear and unpredictable fashion. Small genetic differences between species manifest in profound physiological and biochemical differences which preclude extrapolation from one to another. For example, chimpanzees - so genetically similar to humans - are essentially immune to HIV, hepatitis and malaria; all of which are serious diseases for us. Rats cannot predict carcinogenicity for mice and vice versa. Animals exposed to cigarette smoke for years failed to predict lung cancer in humans. The answers to human diseases will be found by investigating the differences between individuals at the level of SNPs (single nucleotide polymorphisms) - not by artificially inducing imitation diseases in species which are separated from us by millions of years of evolution. Yours faithfully, Europeans For Medical Advancement Response #2 It is the very "complexity of the intact animal body" of which Charles G. Smith writes (Nature 431, 09 September 2004) that makes experiments conducted on animals unreliable for application to the human body. There are so many functional as well as physiological differences between species that experiments conducted on mice, for instance, do not always yield information applicable to rats. Some of the differences are obvious such as variations in circulatory requirements of species which walk on four legs and those which assume an upright posture. Due to differences between the coronary arteries of dogs and humans, as well as other differences such as in conduction, distribution, valve connections, and the blood clotting mechanism, new procedures based on canine characteristics were often fatal for the first humans upon whom they were tried. Many differences between species are less obvious. They consist of innumerable variations in the way drugs are absorbed and distributed by the body. In addition, there are minute interactions at cellular and even molecular levels that can render a drug beneficial for one species lethal for another. Another problem with animal models is that other species are usually not afflicted with human diseases. In order to test new drugs, researchers must resort to artificially creating the symptoms of human diseases in animals. Mere symptoms are not necessarily the same as the disease itself, however, and artificially induced disease is not the same as that which arises spontaneously by circumventing the body's immune system. A more sophisticated approach involves breeding genetically-altered strains of animals that are susceptible to a disease, often by inserting human genes into their bodies, but it is not clear how this affects other functions of the animal's body that differ from those of humans. The only way to obtain results that are reliable for humans is to work exclusively with human tissues, cells, and computer simulations before beginning to observe the effects of low concentrations in human volunteers and eventually, with their consent, in patients suffering from the disease but only with the intention of helping them. Alexander Fleming probably saved the life a desperately ill patient for whom there was no hope by administering untested penicillin which had failed to work in rabbits because they almost immediately excrete it. Had he been working with guinea pigs instead of rabbits, this valuable drug would probably have been discarded before it reached clinical trial because penicillin is lethal for guinea pigs. California dentist Les Stewart is one of the thousands of medical professionals who have denounced the use of other species for information on human disease. He described "experimental research on animals to find the causes and cures for human ailments" as "pure folly --at best an appalling waste and diversion of resources and at worst the cause of much human suffering and disease." USA |
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The Civil Abolitionist Autumn 2004 v.15 no. 2 Due to inadequate funds, this is the final paper issue . Web page will continue to be updated at irregular intervals however. |