Rats help in research on juvenile diabetes

Press, 15 August 1984, Page 25

Rats help in research on juvenile diabetes

NZPA-AP Boston Replacing defective white blood cells can prevent diabetes in laboratory rats, and researchers say the discovery may lead to a way to prevent people from getting this disease. The goal is to find ways to ward off juvenile diabetes, a dangerous, inherited disease that destroys the body’s ability to make insulin.

A strain of rat called the BB rat gets a form of the disease that is very similar to human juvenile diabetes and has become an important testing ground for theories about how diabetes works.

The latest study, conducted at the University of Massachusetts Medical School in Worcester, has

focused the search for the cause of rat diabetes to a particular form of lymphocyte, or white blood cell, called the T cell.

“Our data suggests that the defect is in a T cell, and it also suggests that we can reverse it by administering this T cell from healthy animals”, said Dr Aldo Rossini, who directed the study. In both rats and humans, T cells are an important branch of the body’s disease-fighting immune system. Many experts believe that juvenile diabetes in people results from a foul-up somewhere in this system. The victim’s body turns on itself and kills the tissue known as Beta cells that produces insulin. Unlike those who get diabetes in middle age and

beyond, victims of juvenile diabetes must take insulin injections. Even with this treatment, the disease is a big cause of blindness and also results in heart attacks, kidney failure, and loss of limbs. i

Last year, University of Massachusetts researchers found that something in blood from healthy rats seemed to prevent the disease in rats with the genetic susceptibility for diabetes. After transfusions the rats did not develop diabetes.

The next step in the research, published in the July issue of the “Journal of Clinical Investigation,” found that healthy T cells were the key blood ingredient that transfers resistance to diabetes in the rats.

Even when human diabetes runs in a family, most children do not get it. One medical challenge is to find a test that will reveal who is likely to have the disease before their insulin-pro-ducing cells are destroyed. When this becomes possible, doctors will need a treatment that will head off the disease.

T cells produce powerful hormones that regulate the body’s response to germs and cancer. There are several different kinds of T cells, all with different jobs in fighting disease. If researchers can learn which particular T cells are crucial to preventing diabetes, it may be possible to give people susceptible to the disease the hormones needed to block it.