The Draize eye test
John. H. Draize, a scientist at the FDA developed this test in 1944 to assess eye irritation caused by various chemicals. During the test chemicals are dropped into one eye, and the other eye is left clean to use as a control. The rabbits tested on are restrained so they can not move and react to the chemical irritations, and the eyes are checked after one hour, then at 24 hour intervals for up to 14 days.
Acute Toxicity
This test is used to determine the danger of exposure to a chemical by mouth, skin or inhilation. This test meant poisoning large groups of animals in Lethal Dose 50 tests which are conducted until at least half of the animals are dead. A different toxicity test is the fixed dose method, which does not use death as the endpoint for the experiment; signs of ailments or suffering will usually terminate the experiment. Other tests include the acute toxic class method and the up and down procedure, which typically involve the use of smaller numbers of animals, but during these tests the animals will often have to endure extreme pain, convulsions, loss of motor function, and uncontrollable seizures.
Skin Irritation
Skin irritation tests assess the potential of a substance to cause irreversible damage to the skin. These tests determine the level of damage caused to skin such as itching, swelling and inflimmation. The test is usually reffered to as the Draize Skin Test and involves putting chemicals on a shaved patch of skin and using another shaved patch as a control.
Skin Sensitization
This test is used to determine if a chemical causes an allergic reaction. In the past, skin sensitization tests were usually performed on guineapigs who had substances applied on the surface or injected into their skin. In the Guineapig Maximization test, a chemical adjuvant is injected with the test substance to boost the immune reaction. In the Buehler test, o adjuvant is used but the test is less sensitive. In both of these skin sensitization tests, multiple doses are applied in order to create an allergic reaction.
Mutagenicity and Carcinogenicity
A mutagen is a physical or chemical agent that changes the genetic information of an organism and thus increases the frequency of mutations. As many mutations cause cancer, mutagens are typically also carcinogens. In the bone marrow cytogenetic test, chemicals are administered to the test animals, usually rats or mice, who are later killed. The animal's bone marrow is the evaluated to examine the effects on the nucleus of the blood cells. A carcinogen is a substance or a mixture of substances that induces cancer or increases the incidences of cancer. Rats and mice are typically used for testing carcinogenicity. The test chemical is administered orally, placed on the skin, or inhaled in a two year period. Animal health is monitored throughout the test period but most information is obtained when the animals are killed and their tissue and organs are examined.
Reproductive and developmental toxicity
Reproductive toxicity includes the toxic effects of a substance on the reproductive ability of an organism, and the toxic effects on the development of it's offspring (wow, can you even IMAGINE that being allowed with humans? no, no you can't. I know which group I'd rather it did happen to... cough cough) Developmental toxicity testing involves giving pregnant female animals, usually rats and rabbits, doses of chemicals administered orally. The animals are killed just prior to delivery and the fetus's are examined for any sign of toxic effects by the test substance.
Alternatives to animal testing
In Vitro Testing
Studies which are In Vitro are performed using cells or biological molecules which are studied outside of their natural context.
Harvard's Wyss Institute has created organs-on-chips that contain human cells grown in a state of the art system to mimic the structure and function of human organs and organ systems. The chips can be used instead of animals in disease research, drug testing, and toxicity testing and have been shown to replicate human physiology, diseases, and drug responses more acturately than crude animal experiments do.
Computer (In Silico) Modeling
Researchers have developed a wide range of sophisticated computer models that simulate human biology and the progression of developing diseases. Studies show that these models can accurately predict the ways that new drugs will react in the human body and replace the use of animals in exploratory research and many standard drug tests
Research with human volunteers
A method called Microdosing can provide vital information on the safety of an experimental drug and how it is metabolised in humans prior to large scale human trials. Volunteers are given an extremely small one-time drug dose, and sophisticated imaging techniques are used to monitor how the drug behaves in the body. Microdosing can replace certain tests on animals and help screen out drug compounds that won't work in humans so that they won't needlessly advance to government-required animal testing.
Human-Patient simulators
Strikingly like-like computerised human-patient simulators that breathe, bleed, convulse, talk and die have been shown to teach students physiology pharamcology better than exercises that involve cutting up animals. The most high tech simulators mimix illness and injuries and give the appropriate biological response to medical interventions and injections of medication. 97% of medical schools in the US have completely replaced the use of animal labratories in medical training with simulators like this, as well as virtual reality systems, computer simulators and supervised clinical experience.
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