Animal ExperimentationIn this chapter and the one that follows, you will be reviewing space flight investigations that were carried out using laboratory rats, including the muscle study that was designed by Dr. Kenneth Baldwin from the University of California at Irvine. We will be reviewing some of the objectives, methods, and results of his study in a moment. For now, though, it is important to discuss animal experimentation in general, because this is a topic that has touched each and every one of our lives. This section is not meant to end the debate on whether and how animals are used in research but, instead, it is meant to bring this topic out into the open so that debate can continue. You see, continued debate of this issue can serve as a way to ensure that we remain informed enough to judge for ourselves the necessity and merit of continuing this type of research. Our knowledge will also ensure that researchers who use animals remain accountable to their moral and scientific obligations to carry out only justifiable and humane animal studies.
Those who support animal experimentation claim that many of the cures for deadly diseases have been developed through experimentation on animals - and that is true. Those who oppose animal experimentation tell of terrible stories about how animals have been mistreated in some of the laboratories where they were used as experimental subjects - and this has happened in cases where researchers have behaved in inappropriate ways. The use of animals in science may not have always been as well-justified or well-executed as today's sensibilities require. Today, far fewer animals are used in research than are used for other purposes. An estimated 17 to 22 million vertebrate animals are used each year in research, education, and testing - less than 1% of the number killed for food. About 85 percent of these animals are rats and mice that have been bred for research. The other 15% include other small rodents, dogs, cats, rabbits, monkeys, and chimpanzees.
Scientists assume two major responsibilities when they study animals in research. The first is to ensure that the use of animals contributes to the advancement of knowledge that will benefit other living things. Not only are animals used to study diseases that afflict human beings but they are also used to improve veterinary treatments for other animals so that the quality of life of all living things can be improved. The second responsibility is to minimize any possible pain or distress that the animals may experience during the performance of an experiment. Whether you feel good, bad, or indifferent about the use of animals in the laboratory, we can all feel united by the fact that no one should ever cause an animal to suffer.
Why is there a need for animal experimentation? The reason for any experiment is to gain new knowledge that can be applied to the benefit of other living things. By studying animals, it is possible to obtain information that cannot be learned any other way. For instance, sometimes a scientist uses animals as experimental models to study human function; such models have biological similarities to humans that make them particularly useful for studying how to treat specific diseases. In these studies, many animals can be fed identical and closely monitored diets and can be housed under certain environmental conditions that can be totally controlled. In many cases, it is impossible to obtain the necessary number of human subjects that would be required to carry out a human study under such controlled situations and for such long periods of time. Sometimes a scientist requires the use of special techniques that require surgically entering the body to study some feature. When a new drug or surgical technique is developed, society deems it unethical to use that drug or technique first in human beings because of the possibility that it would cause harm rather than good. Many people question why these experimental procedures even have to be done at all.
Let's consider this question. A hundred years ago, good health was much more rare than it is today. In 1870, the leading cause of death in the United States was tuberculosis. Of all the people born in developed countries like the United States, a quarter were dead by the age of 25, and about half had died by the age of 50. Today, fully 97% of Americans live past their 25th birthday, and over 90 percent live to be older than 50. Better nutrition and sanitation did much to reduce the toll from infectious diseases. But these diseases could not have been eliminated as significant causes of death and illness without animal research. Today, animal research has contributed to the development of many important drugs, surgical techniques, and therapies that have helped us become a healthier population. For instance, animal research has resulted in the development of: chemotherapy approaches used in the treatment of cancer; drugs and techniques that greatly increase the chance for survival during organ transplant procedures; the drug lithium for the treatment of depression; a technique known as balloon angioplasty for the treatment of cardiovascular disease; vaccines against diphtheria, whooping cough, tetanus, and polio that we received as children; and antibiotics used to treat everything from minor infections to severe illnesses. Nearly half of the biomedical investigations carried out in the United States would not have been possible without laboratory animals.
Also, the same methods that have been developed to prevent and treat diseases in humans have improved the lives of countless animals. The animals that we keep as pets and raise for food would live shorter and less healthy lives were it not for animal research. Vaccines, antibiotics, anesthetics, surgical procedures, and other approaches developed in animals for human use are now commonly employed throughout veterinary medicine. Pets, livestock, and animals in zoos live longer, more comfortable, and healthier lives as a result of animal research. And in many cases, treatments have been developed specifically for animals. Vaccines for rabies, canine parvovirus, distemper, and feline leukemia virus have kept many animals from contracting these fatal diseases. In fact, treatments for heartworm infestation, a painful and ultimately fatal affliction in dogs, have been made possible through the use of research animals.
Animal research has also been integral to the preservation of many endangered species. The ability to eliminate parasitism, treat illnesses, use anesthetic devices, and promote breeding has improved the health and survival of many species. Through techniques like artificial insemination and embryo transfer, species that are endangered or have disappeared in the wild can now be managed or maintained. Research on the sexual behavior of animals has made it possible to breed many species in captivity, enabling endangered species to be reintroduced to the wild.
While it is often impossible to obtain full agreement by everyone about all of the issues related to animal experimentation, each person's opinion should always be respected. It is not difficult, however, to obtain everyone's full agreement with the principle that the humane and kind treatment of animals should be of primary importance throughout the scientific community. And it is not difficult to understand that animal research has taught us more about the world we live in and about the living things that inhabit that world. It is the responsibility of all of the life scientists throughout the world to perform their studies with the utmost respect for all living things. Everyone should insist that any experiment that involves the use of animals be carried out with careful and kind treatment of those animals.
In the next section, we will briefly discuss how your muscle types can
change due to changing physical and environmental circumstances. This will
lead us right into a discussion of how the absence of gravity can affect
the types of muscles that astronauts maintain as well as the overall
strength of these muscles. Remember that, in order to study the muscle, a
scientist must be able to see the muscles directly. A proper muscle study
requires more tissue than an astronaut should expect to donate, and so you
should be aware that we will be discussing how animal tissues were used to
study muscles in space.