Rats

More is known about the anatomy and physiology of the rat than just about any other non-human animal, and the use of rats in biomedical research has resulted in tremendous advances in biology and medicine. Due to their short life span, rats, like mice, have made important contributions to the study of the aging and age-related diseases such as arteriosclerosis.

The rat is also an important model for the study of arthritis and myasthenia gravis, both considered autoimmune diseases.

Rats are one of the most important animals used in cancer research because they are susceptible to the development of tumors, either spontaneously or through the application of chemicals or viruses. They can also serve as excellent hosts for transplanted tumors, and are needed for the screening of potential cancer-causing substances.

The rat model has also provided great insights in diabetes and cardiovascular research, particularly in the study of hypertension. As with mice, laboratory rats are useful models for the study of reproductive biology because they reproduce readily and in large numbers.

The rat is the major animal used in studies of organ transplantation. Many of the advances in understanding of the immune mechanism involved in tissue rejection have come from studies in the rat. This is because the rat is large enough in size to make surgical procedures relatively easy to perform, and also because much is known about the immune system of the rat.