Predicting toxicity, corrosivity, and other safety variables, as well as the effectiveness of a new product for humans, in addition to testing chemicals, medical devices, and new drugs involve the use of animals. Many of these experiments cause pain to the animals involved, or reduce their quality of life in other ways.
Laboratory animals are most commonly used in biomedical research, education, and product safety testing. Biomedical researchers use animals in their efforts to understand the workings of the body and the processes of disease and health, and to develop new vaccines and treatments for various diseases.
This sort of research is not for the benefit of human health only, but it is also aimed at developing new veterinary techniques. Industry, on the other hand, uses animals to test the safety and effectiveness of a wide range of consumer products, including drugs, cosmetics, household cleaning products, pesticides, industrial chemicals, and more.
There is a set of principles that scientists are encouraged to follow in order to reduce the impact of research on animals: reduction, as in reducing the number of animals used in a procedure; refinement, as in refining the procedures used in experiments to alleviate or minimize potential animal pain; and replacement, as in replacing the procedures that use animals with procedures that does not use animals.
Today, because experiments on animals are cruel, expensive, and sometimes inadequate, the world’s most forward-thinking scientists have moved on to develop and apply alternative methods for studying diseases and testing products. Animals are replaced, either by methods that do not involve animals at all—absolute replacement—or by those that use only the cells or tissues of animals—relative replacement.
These modern methods include sophisticated tests using human cells and tissue, computerized patient-drug databases and virtual drug trials, computer models and simulations, and stem cell and genetic testing methods.
Alternatives to the use of animals in toxicity testing include replacing animal tests with non-animal methods, as well as modifying animal-based tests to reduce the number of animals used. Several non-animal methods have been formally validated and accepted by some countries as replacements for an existing animal test; such as embryonic stem cell test using mouse-derived cells to assess potential toxicity to developing embryos, has been validated as a partial replacement for birth-defect testing in rats and rabbits.
Human skin model tests are now in use, including the validated EpiDerm test, which has been accepted almost universally as a total replacement for skin corrosion studies in rabbits. The use of human skin leftover from surgical procedures or donated cadavers can be used to measure the rate at which a chemical is able to penetrate the skin.
Microdosing can provide information on the safety of an experimental drug and how it is metabolized in the body by administering an extremely small one-time dose that is well below the threshold necessary for any potential pharmacologic effect to take place.
Computer modeling also can replace certain kinds of animal use, particularly in education. Some biology classes started to practice dissection on a computer model rather than on real living frogs. Even medical schools are beginning to develop “virtual reality” devices for students to practice on. Plastic models and realistic manikins also can take the place of live animals for some educational purposes.
Redesigning studies to collect as much information as possible from the same set of animals can also reduce animal usage. For example, if one researcher is studying rat brain tissue, when killing the rat, he can allow other researchers to use the kidneys, liver, or other parts of the animal for their own studies. Some alternative methods involve using lower organisms in place of species higher on the evolutionary scale. Such studies may use plants, microorganisms, invertebrate animals, or even early-stage vertebrates rather than vertebrate animals.
Unfortunately, replacement of animals is not always possible. Until now, some important kinds of testing just cannot be done without animals, at least nowadays. In these cases, researchers can still work to reduce the number of animals used in a given study. With careful experimental design and sophisticated statistical techniques, it is often possible to use far fewer animals and still obtain valid results.
References
sciencemag.org
hirnforschung.kyb.mpg
*Published in SCIplanet Printed Magazine, Summer 2014 Issue "Environment "
*See also Animal Testing Nightmare.