Two Army scientists have enabled animals paralyzed by spinal-cord injuries to walk by injecting them with a drug.
If their revolutionary treatment continues to prove effective in animal and then human trials, it could offer the first real hope to the thousands of humans paralyzed every year in auto crashes and other accidents.
The feat, a series of discoveries based on new knowledge of the brain and brain chemicals, was performed at the Walter Reed Army Institute of Research here. Walter Reed Drs. Alan Faden and John Holaday are to report on it today before the Federation of American Societies for Experimental Biology, meeting in Anaheim, Calif.
In their research, Faden and Holaday first created paralyzing spinal-cord injuries in anesthetized cats.
After waiting 45 minutes, to simulate the probable situation in treating human injury, they injected the cats with naloxone, a drug widely used to counter heroin and morphine overdoses.
Within 24 hours, most of the cats could walk again -- some of them normally, others with some spasticity or jerkiness.
Of the first six cats injected, all could walk by the time they were sacrificed after 24 hours. Of nine cats injected later, three walked normally, four walked in a mildly jerky fashion, and two died, which is not uncommon after spinal-cord injury.
All the cats were sacrificed, after three weeks at longest, so the scientist could study the drug's action.
"It is unlikely that there would be any reversal of the healing after three weeks," Holaday said yesterday. "If anything, there probably would be further improvement."
How soon might the drug be tried in humans, if the animal work continues to go well? "I don't think this will happen this year," was all Holaday would say.
"We want to be cautious and proceed slowly. We will keep some animals alive for long periods to observe long-term effects. We want to make sure we know what we're doing."
The doctors also say that no drug can help prevent spinal-cord injury unless it is given quickly, before cells die.
Doctors in some hospitals are trying to use cortisone-like drugs to prevent permanent spinal-cord damage, but no striking results have been reported.
Faden is a neurologist and a major in the Army Medical Corps. Holaday is a civilian pharmacologist, or specialist in drug effects, and a former Army Medical Corps captain. They were aided by Tom Jacobs and Dr. Donald Rigamonti.
Their work started not with spinal-cord damage but with study of the common physiological problem called shock, a train of events that can cause death in injured persons.
In recent years, scientists have been making one discovery after another about a new-found class of brain chemicals called endorphins. They are often called "the brain's own opiates" because of their role in relieving pain.
In rats, dogs and cats, the Army scientists believe they have shown that endorphins, far from being always beneficial, apparently play a role in causing shock. They do this, it seems, by helping produce a severe drop in blood pressure.
By giving bacterial toxins or causing spinal-cord injuries or causing blood loss, Holaday and Fader repeatedly induced shock and low blood pressure in their animals.
Then they used naloxone -- a known antagonist or counter to the endorphins, as well as to morphine and heroin -- to restore blood pressure and relieve the shock, dramatically saving the animals' lives.
That work then led the Army scientists to test naloxone on spinal-cord injury, where there is so severe a decrease in blood flow that it kills cells.
In collaboration with the Walter Reed scientists, doctors at several medical centers have begun a trial of naloxone in humans in shock.