by Jennifer Allsbrook

Created on: July 03, 2008

Animal testing plays a crucial role in the development of surgical techniques, pharmaceutical products and other products meant for human consumption and use. For example, primate use led to the development of the rubella vaccine, the anti-rejection drug cyclosporin, and cornea, heart, and lung transplant techniques. (1) The ability to ascertain the effects of chemicals on living systems is fundamental in drug research and development. Computer modeling of how drugs, such as an inhibitor of some ion channel or receptor protein embedded in a cell's membrane, will affect the whole organism is unlikely to be as reliable as animal testing. Organisms are intricate "machines" with multiple parts that must be able to communicate with one another in concert. Metabolism is finely tuned with feedback mechanisms in place to control and regulate biosynthesis, catabolism, gene expression or any of a broad host of other life processes. Without the use of living systems, a drug's affect would be nearly impossible to determine. How could a surgeon learn his/her trade without first dissecting and learning anatomy? The use of dogs enabled kidney transplantation and open-heart surgical techniques. (1)

Signal transduction pathways, the main mechanism of cell-to-cell communication, are some of the most complex biochemical interactions in living things. For example, epinephrine, also known as adrenaline, binds to receptors on a cell's surface called G-protein-linked receptors. These proteins undergo a conformational shift that activates a G-protein that in turn activates another protein and so on in a cascade of cellular action called transduction. This ultimately leads to a cellular response. In this case the response is the activation of enzymes that aid the catalysis of glycogen into its glucose monomers that can be utilized for cellular energy. (2) This is one pathway in the many that make up life processes. How can we possibly predict how some new drug may alter this or any other pathway without first testing it? Some 60% of the medicines that we use today are thought to target G-protein-linked receptor pathways. (2) Do you want to take the chance that they might work?
Researchers in the scientific community have adopted the three R's' to govern the use of animals in their research: Reduction, Refinement, and Replacement. (3) Reduction implies using fewer animals for required tests. Refinement involves designing experiments that lower and try to eliminate the animal suffering

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