Laser Doppler flow and brain tissue PO2 after cortical impact injury complicated by secondary ischemia in rats treated with arginine.
BACKGROUND
Traumatic brain injury (TBI) makes the brain susceptible to secondary insults such as ischemia. This study tested the hypothesis that L-arginine would increase regional CBF (rCBF) and brain tissue PO2 (PbtO2) at the injury site.


METHODS
A secondary insult model was employed in rodents. rCBF was measured with laser doppler flowmetry (LDF) and PbtO2 with a PO2 catheter at the impact site. Animals were randomized to receive L-arginine, D-arginine or saline intravenously, 5 minutes after impact.


RESULTS
In animals who received L-arginine, the percentage rCBF from baseline (%CBF) was higher at the impact site after impact (p < 0.001), during bilateral carotid occulation (BCO) (p = 0.001) and during reperfusion (p = 0.032). In contrast, PbtO2 was not significantly increased throughout the experiment for the L-arginine group.


CONCLUSIONS
Administration of L-arginine increased rCBF in the injured brain tissue, and resulted in better preservation of CBF during BCO than D-arginine and saline.
Mendez
Donna R
DR
Department of Pediatrics/Emergency Medicine, Baylor College of Medicine, Houston, Texas 77030, USA. drmendez@texaschildrenshospital.org
Cherian
Leela
L
Robertson
Claudia S
CS
D000704:Analysis of Variance; D000818:Animals; D001120:Arginine / Q000494:pharmacology / Q000627:therapeutic use*; D001783:Blood Flow Velocity / Q000187:drug effects; D001784:Blood Gas Analysis; D001923:Brain Chemistry / Q000187:drug effects*; D001930:Brain Injuries / Q000150:complications*; D002545:Brain Ischemia / Q000209:etiology / Q000378:metabolism / Q000503:physiopathology / Q000517:prevention & control*; D002560:Cerebrovascular Circulation / Q000187:drug effects*; D004195:Disease Models, Animal; D004353:Drug Evaluation, Preclinical; D006439:Hemodynamics / Q000187:drug effects; D007262:Infusions, Intravenous; D007427:Intracranial Pressure / Q000187:drug effects; D017078:Laser-Doppler Flowmetry; D008297:Male; D009569:Nitric Oxide / Q000502:physiology; D010100:Oxygen / Q000378:metabolism*; D010101:Oxygen Consumption / Q000187:drug effects; D011897:Random Allocation; D051381:Rats; D020318:Rats, Long-Evans; D012965:Sodium Chloride / Q000627:therapeutic use; D013997:Time Factors
D009569:Nitric Oxide; D012965:Sodium Chloride; D001120:Arginine; D010100:Oxygen