Kidney Disease

The normal human body has two kidneys, each about the size of a fist, located on either side of the spine below the rib cage. The kidneys perform vital functions necessary for maintaining life. They maintain body fluid levels by excreting fluids when the body has an excess amount and conserving fluids when the body fluid level is low. The kidneys assist in regulating blood pressure by excreting excess fluid and by secreting a chemical called renin. A variety of other chemicals are produced and released by the kidneys so that a balance is always maintained to keep the body healthy. In addition, the kidneys filter the entire blood supply every two minutes in order to remove waste from the blood and eliminate it in the urine.

Diseases of the kidneys and urinary tract afflict 14 million North Americans (including more than 1 million Canadians) and take the lives of 50,000 people each year. These diseases include cancer; infection (causing conditions such as pyelonephritis, an inflammation of the kidney tissue); obstructions such as kidney stones, cysts and congenital abnormalities; defects in the filtering mechanism of the kidneys; and abnormal leakage of protein into the urine (nephrosis). In addition, urinary tract infections are common, particularly in women. Kidney failure leaves its victims in a state of chronic illness.

Hypertension (high-blood pressure, experienced by over two million Canadians) often accompanies kidney disease, while diseases such as diabetes may damage kidney function. Researchers are currently using animal models to investigate how cardiovascular disease, caused in some cases by hypertension, leads to kidney failure.

Thanks in part to experiments with dogs, the artificial kidney (dialysis machine) was developed to take over kidney function. Each year thousands of people benefit from kidney transplantation, the oldest and most successful form of large organ transplantation. Rodents, dogs and other animals are helping investigators determine innovative approaches for circumventing transplant rejection to prolong kidney transplants.

Research into kidney failure led to the recognition that the normal kidney produces a hormone called erythropoietin. Erythropoietin controls the production of red blood cells and is deficient in patients with kidney failure, resulting in chronic anemia and a requirement for multiple blood transfusions. Using genetic engineering techniques, erythropoietin can be produced in large quantities in the laboratory for the treatment of patients with kidney disease. Additional applications of the use of this hormone are currently being studied in animal models.

The development of monoclonal antibodies, highly specific molecules that can react with and identify subtle differences in kidney structures and in cells that cause kidney disease, was derived from experiments in mice, which led to the 1984 Nobel Prize in Medicine. Monoclonal antibodies are now being used successfully to reverse certain types of kidney transplant rejection in people. Development of more and better antibodies continues.