Neurology: Testing Method for Spinal Cord Injuries

Photo: Laboratory

Researchers developed a new method to detect the toxin acrolein; © pan- Liebiedieva

A medical test previously developed to measure a toxin found in tobacco smokers has been adapted to measure the same toxin in people suffering from spinal cord injuries and multiple sclerosis, offering a potential tool to reduce symptoms.

The toxin, called acrolein, is produced in the body after nerve cells are injured, triggering a cascade of biochemical events thought to worsen the injury's severity. Acrolein (pronounced a-KRO-le-an) also may play an important role in multiple sclerosis and other conditions.

Because drugs already exist to reduce the concentration of acrolein in the body, being able to detect and measure it non-invasively represents a potential treatment advance, said Riyi Shi of Purdue University's Department of Basic Medical Sciences.

"If the acrolein level is high it needs to be reduced, and we already have effective acrolein removers to do so," Shi said. "Reducing or removing acrolein may lessen the severity of symptoms in people who have nerve damage, but there has not been a practical way to monitor acrolein levels in nervous system trauma and diseases."

The toxin is present in tobacco smoke and air pollutants. A method had been developed previously to detect and measure acrolein in the urine of smokers, but it has not been used in people suffering from conditions in which the body produces acrolein internally.

"Based on this method, it was revealed that acrolein is significantly elevated in smokers and decreases following the cessation of cigarette smoke," Shi said. "However, such a method has not been widely used for conditions in which acrolein is elevated due to central nervous system damage or disease."

The researchers tested the method in laboratory animals. "We wanted to see if higher levels of acrolein corresponds to greater severity of spinal cord injury, and the answer is yes," said Shi. "This means reducing acrolein may help to control symptoms."

The method does not detect acrolein directly but determines the presence of a byproduct, or metabolite, of acrolein in the urine. The metabolite is a chemical compound called N-acetyl-S-3-Hydroxypropylcysteine, or 3-HPMA.

"Acrolein is very volatile, so it doesn't remain stable long enough to monitor, but one molecule of acrolein will make one molecule of 3-HPMA, which is very stable in urine," Shi said.

Laboratory rats were injected with different doses of acrolein, and findings showed that the detection technique is able to accurately measure these differences in acrolein concentration in the urine. The technique might one day be performed routinely in a doctor's office. "The non-invasive nature of measuring 3-HPMA concentrations in urine allows for long-term monitoring of acrolein in the same animal and ultimately in human clinical studies," Shi said.; Source: Purdue University