University of Texas Medical Branch at Galveston
An interdisciplinary research team led by The University of Texas Medical Branch at Galveston reports a new breakthrough in countering the deadly effects of radiation exposure.
A single injection of a regenerative peptide was shown to significantly increase survival in mice when given 24 hours after nuclear radiation exposure. The study currently appears in Laboratory Investigation, a journal in the Nature Publishing group.
UTMB
lead author Carla Kantara, postdoctoral fellow in biochemistry and molecular
biology, said that a single injection of the investigative peptide drug TP508
given 24 hours after a potentially-lethal exposure to radiation appears to
significantly increase survival and delay mortality in mice by counteracting
damage to the gastrointestinal system.
The
threat of a nuclear incident, with the potential to kill or injure thousands of
people, has raised global awareness about the need for medical countermeasures
that can prevent radiation-induced bodily damage and keep people alive, even if
given a day or more after contact with nuclear radiation.
Exposure to high doses of radiation triggers a number of potentially lethal effects. Among the most severe of these effects is the gastrointestinal, or GI, toxicity syndrome that is caused by radiation-induced destruction of the intestinal lining. This type of GI damage decreases the ability of the body to absorb water and causes electrolyte imbalances, bacterial infection, intestinal leakage, sepsis and death.
The
GI toxicity syndrome is triggered by radiation-induced damage to crypt cells in
the small intestines and colon that must continuously replenish in order for
the GI tract to work properly. Crypt cells are especially susceptible to
radiation damage and serve as an indicator of whether someone will survive
after total body radiation exposure.
"The
lack of available treatments that can effectively protect against
radiation-induced damage has prompted a search for countermeasures that can
minimize the effects of radiation after exposure, accelerate tissue repair in
radiation-exposed individuals and increase the chances for survival following a
nuclear event," said Darrell Carney, UTMB adjunct professor in
biochemistry and molecular biology and CEO of Chrysalis BioTherapeutics, Inc.
"Because radiation-induced damage to the intestines plays such a key role
in how well a person recovers from radiation exposure, it's crucial to develop
novel medications capable of preventing GI damage."
The
peptide drug TP508 was developed for use in stimulating repair of skin, bone
and muscle tissues. It has previously been shown to begin tissue repair by
stimulating proper blood flow, reducing inflammation and reducing cell death.
In human clinical trials, the drug has been reported to increase healing of
diabetic foot ulcers and wrist fractures with no drug-related adverse events.
"The
current results suggest that the peptide may be an effective emergency nuclear
countermeasure that could be delivered within 24 hours after exposure to
increase survival and delay mortality, giving victims time to reach facilities
for advanced medical treatment," Kantara said.
