Hydroethidine Detection of Reactive Oxygen Species Production during Status Epilepticus.
Abstract number :
1.027
Submission category :
Year :
2001
Submission ID :
1183
Source :
www.aesnet.org
Presentation date :
12/1/2001 12:00:00 AM
Published date :
Dec 1, 2001, 06:00 AM
Authors :
S.L. Peterson, PhD, College of Pharmacy, University of New Mexico, Albuquerque, NM; S. Liu, PhD, College of Pharmacy, University of New Mexico, Albuquerque, NM; K.J. Liu, PhD, College of Pharmacy, University of New Mexico, Albuquerque, NM
RATIONALE: Reactive oxygen species (ROS) generated by N-methyl-D-aspartic acid (NMDA) receptor activation have been implicated in the neuropathology associated with the status epilepticus (SE) induced by lithium-pilocarpine (Li-Pilo) treatment in rats. Hydroethidine (HEt) is oxidized to ethidium (Et) selectively by superoxide free radical but not other ROS. This study characterizes the regional distribution of superoxide production during Li-Pilo-induced SE.
METHODS: Anesthetized rats were implanted with ECoG electrodes to verify onset of SE. Following one week to allow recovery from the surgery, an injection of 3 mmol/kg SQ lithium chloride was followed 24 hours by 20 mg/kg SQ pilocarpine. At onset of continuous high amplitude cortical afterdischarge the rats were injected with 1 mg of HEt IP. Following one hour of SE rats were sacrificed and the brains prepared for fluorescence microscopy.
RESULTS: Rats treated with HEt (n=4) demonstrated marked Et fluorescence in the pyriform cortex and lateral amygdala indicating superoxide production. Et fluorescence was also present but much less evident in the CA1 and CA3 regions. Control rats (n=2) administered HEt without SE did not demonstrate fluorescence.
CONCLUSIONS: The results indicate that superoxide is produced in regions known to be injured by Li-Pilo-induced SE. The apparent regional variation in superoxide production suggests regional differences in ROS-mediated neuropathology.
Support: American Heart Association 004004NI and NIH P20 RR15636