Neuroprotective effects of nicotinamide after experimental spinal cord injury.
OBJECTIVE
To investigate the ability of nicotinamide to protect against secondary damage in spinal cord tissue after an experimental injury. Trauma to the spinal cord induces a cascade of cellular events that lead to progressive tissue injury over time. Nicotinamide has been shown to affect many elements of this cascade, including excitatory amino acid release, inflammation, apoptosis, and cellular energy balance.


METHODS
Male Long-Evans (n = 12) rats received an excitotoxic spinal cord injury by intraspinal injection of quisqualic acid (QUIS), a glutamate receptor agonist. A second set of rats (n = 4) received intraspinal saline as a sham injury. Thirty minutes after injury, animals that had QUIS injections received an intraperitoneal injection of either saline (control, n = 4) or nicotinamide (500 mg/kg, n = 8). Seven days postinjury, the spinal cords were removed, and serial sections were cut, mounted on slides, and stained. By using light microscopy, the extent of tissue damage was assessed at the epicenter of injury as well as sections up to 450- microm rostral and 450- microm caudal to the epicenter.


RESULTS
Only those animals receiving QUIS injections showed damaged tissue. There was no significant difference in the amount of damage at the epicenter of injury between the saline- and nicotinamide-treated animals. However, when comparing the total amounts of damage over the 975- microm length of cord examined, the rostro-caudal extent of injury was significantly reduced in the nicotinamide-treated animals compared with the saline-treated animals.


CONCLUSIONS
Systemic nicotinamide serves to limit the rostro-caudal extent of cell death after experimental spinal cord injury.
Brewer
Kori L
KL
Department of Emergenvy Medicine, Brody School of Medicine at East Carolina University, Greenville, NC 27858, USA. brewerk@mail.ecu.edu
Hardin
J Shane
JS
D000208:Acute Disease; D000818:Animals; D004195:Disease Models, Animal; D018690:Excitatory Amino Acid Agonists / Q000008:administration & dosage; D007249:Inflammation / Q000188:drug therapy / Q000473:pathology; D007278:Injections, Spinal; D008297:Male; D018696:Neuroprotective Agents / Q000627:therapeutic use*; D009536:Niacinamide / Q000627:therapeutic use*; D016318:Quisqualic Acid; D051381:Rats; D020318:Rats, Long-Evans; D012965:Sodium Chloride / Q000627:therapeutic use; D013116:Spinal Cord / Q000187:drug effects / Q000473:pathology; D013119:Spinal Cord Injuries / Q000139:chemically induced / Q000188:drug therapy* / Q000473:pathology; D016896:Treatment Outcome
D018690:Excitatory Amino Acid Agonists; D018696:Neuroprotective Agents; D009536:Niacinamide; D012965:Sodium Chloride; D016318:Quisqualic Acid