Featured Research

from universities, journals, and other organizations

Antioxidant Protects Islet Cells Used In Transplants For Diabetes

Date:
July 29, 2002
Source:
National Jewish Medical And Research Center
Summary:
A synthetic antioxidant developed by researchers at National Jewish Medical and Research Center improves the survival of islet cells used in transplants for diabetes. The findings, reported in the August issue of the journal Diabetes by researchers at the University of Pittsburgh, could help overcome a significant drawback of the "Edmonton Protocol," a promising treatment for diabetes.

A synthetic antioxidant developed by researchers at National Jewish Medical and Research Center improves the survival of islet cells used in transplants for diabetes. The findings, reported in the August issue of the journal Diabetes by researchers at the University of Pittsburgh, could help overcome a significant drawback of the "Edmonton Protocol," a promising treatment for diabetes.

"The antioxidant neutralizes the harmful free radicals generated when islet cells are isolated from the pancreas," said senior author Jon Piganelli, Ph.D., assistant professor of Pediatrics at the Diabetes Institute, Children's Hospital of Pittsburgh, and the University of Pittsburgh School of Medicine. "More of the islet cells survived in culture. And when we transplanted islet cells into diabetic, immunodeficient mice, it took fewer of the antioxidant-treated islet cells to normalize their blood sugar."

In type 1 diabetes, a person's immune system mistakenly attacks and destroys islet cells that secrete insulin necessary for the metabolism of sugar. Many diabetes patients take insulin shots to make up for the lost islet cells. In 2000, researchers from Edmonton, Alberta, reported new techniques that have made islet-cell transplantation a promising option for patients with type 1 diabetes. It allows patients to produce their own insulin. Patients have to take immunosuppressive drugs to prevent rejection of the transplants, but they maintain better control of their insulin levels, thus reducing the chances of future complications. They also avoid the daily insulin injections. Clinical trials of the "Edmonton protocol" are being conducted at several medical centers around the nation.

One drawback to the Edmonton protocol is that pancreata from at least two donors are needed to supply enough islet cells for one successful transplant. Many cells die during isolation and shortly after transplantation. Since islet cells also rapidly die in culture, surgeons are forced to transplant the cells immediately after they have been isolated. This prevents physicians from taking several steps that could improve the likelihood of a successful transplant.

Isolation of the islet cells from the pancreas stresses them, leading to inflammation and islet-cell death. Highly reactive free-radical molecules contribute to this stress. Dr. Piganelli and his colleagues reasoned that an antioxidant compound might help islet cells survive and improve transplant success by neutralizing the free radicals.

The researchers used two synthetic antioxidants developed several years earlier by Dr. James Crapo, M.D., Chairman of the Department of Medicine at National Jewish, and his colleagues. The antioxidants, dubbed AEOL10113 and AEOL10150, mimic the naturally occurring antioxidant superoxide dismutase, but are effective against a wider range of oxygen radicals and last longer in the body. Now licensed by Incara Pharmaceuticals Corporation, they have shown promise in preventing damage to cells caused by stroke and radiation therapy for cancer. Earlier this year, Dr. Piganelli and his colleagues showed that the antioxidants could prevent the development of type 1 diabetes in mice when given T cells that normally causes the disease.

"We are excited that these synthetic antioxidants are protecting cells in such a wide range of hazardous conditions," said Dr. Crapo.

Islet-cell loss was cut in half over a six-day period, from 60% to 30%, when the antioxidants were applied during isolation of the islet cells. The antioxidants also improved the effectiveness of the islet-cell transplants. When large amounts of islet cells (700-1,000 islet equivalents) were transplanted into six diabetic mice, all the animals became healthy. But when smaller amounts of islet cells (200-220 islet equivalents) were transplanted into nine diabetic mice, half the mice who got untreated islet cells remained diabetic while all the animals with antioxidant-treated islet cells returned to full health.

"The antioxidant-treated cells are healthier when they are transplanted into the mice and survive better after the transplant," said Dr. Piganelli. "We think it may be worthwhile to use the antioxidant during preservation of the pancreas, before the isolation begins, and after transplantation."


Story Source:

The above story is based on materials provided by National Jewish Medical And Research Center. Note: Materials may be edited for content and length.


Cite This Page:

National Jewish Medical And Research Center. "Antioxidant Protects Islet Cells Used In Transplants For Diabetes." ScienceDaily. ScienceDaily, 29 July 2002. <www.sciencedaily.com/releases/2002/07/020729074045.htm>.
National Jewish Medical And Research Center. (2002, July 29). Antioxidant Protects Islet Cells Used In Transplants For Diabetes. ScienceDaily. Retrieved July 25, 2014 from www.sciencedaily.com/releases/2002/07/020729074045.htm
National Jewish Medical And Research Center. "Antioxidant Protects Islet Cells Used In Transplants For Diabetes." ScienceDaily. www.sciencedaily.com/releases/2002/07/020729074045.htm (accessed July 25, 2014).

Share This




More Health & Medicine News

Friday, July 25, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Beatings and Addiction: Pakistan Drug 'clinic' Tortures Patients

Beatings and Addiction: Pakistan Drug 'clinic' Tortures Patients

AFP (July 24, 2014) A so-called drugs rehab 'clinic' is closed down in Pakistan after police find scores of ‘patients’ chained up alleging serial abuse. Duration 03:05 Video provided by AFP
Powered by NewsLook.com
Too Few Teens Receiving HPV Vaccination, CDC Says

Too Few Teens Receiving HPV Vaccination, CDC Says

Newsy (July 24, 2014) The Centers for Disease Control and Prevention is blaming doctors for the low number of children being vaccinated for HPV. Video provided by Newsy
Powered by NewsLook.com
New Painkiller Designed To Discourage Abuse: Will It Work?

New Painkiller Designed To Discourage Abuse: Will It Work?

Newsy (July 24, 2014) The FDA approved Targiniq ER on Wednesday, a painkiller designed to keep users from abusing it. Like any new medication, however, it has doubters. Video provided by Newsy
Powered by NewsLook.com
Doctor At Forefront Of Fighting Ebola Outbreak Gets Ebola

Doctor At Forefront Of Fighting Ebola Outbreak Gets Ebola

Newsy (July 24, 2014) Sheik Umar Khan has treated many of the people infected in the Ebola outbreak, and now he's become one of them. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

    Health News

      Environment News

        Technology News



          Save/Print:
          Share:

          Free Subscriptions


          Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

          Get Social & Mobile


          Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

          Have Feedback?


          Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
          Mobile: iPhone Android Web
          Follow: Facebook Twitter Google+
          Subscribe: RSS Feeds Email Newsletters
          Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins