Abstract
The effects of nitric oxide synthase inhibition on brain acidosis, regional cortical blood flow (rCBF), and NADH redox state were examined using in vivo fluorescence imaging during four 15-min periods of moderate focal cerebral ischemia, each separated by three 5-min reperfusion periods followed by a final 3-h reperfusion period. Fasted rabbits under 1.5% halothane were divided into six groups of seven animals each: nonischemic controls, ischemic controls, and the following drug groups receiving N(G)-nitro-L-arginine methyl ester (L-NAME) intravenously 20 rain before repetitive ischemia (as follows: 0.1 mg/kg, 1 mg/kg, 10 mg/kg, and 1 mg/kg ± 5 mg/kg L-arginine). L- NAME at 0.1 and 1 mg/kg prevented the development of significant brain acidosis throughout the four ischemic insults. L-NAME at 10 mg/kg reduced preischemic rCBF by 21% (P < 0.05) and did not mitigate brain acidosis after the third and fourth ischemic insults. Brain intracellular pH returned toward baseline alter the 3-h final reperfusion in all groups. NADH redox state was significantly (P < 0.05) elevated from baseline controls in all groups during the last three ischemic insults. During the final reperfusion period, NADH redox state returned toward baseline values only in the 0.1 mg/kg L-NAME and ischemic control group. In conclusion, low-dose L-NAME attenuated brain acidosis independent from rCBF changes during intermittent, moderate focal cerebral ischemia.
Original language | English (US) |
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Pages (from-to) | H588-H594 |
Journal | American Journal of Physiology - Heart and Circulatory Physiology |
Volume | 271 |
Issue number | 2 40-2 |
DOIs | |
State | Published - Aug 1996 |
Keywords
- NAD/NADH
- intermittent focal cerebral ischemia
- intracellular pH
ASJC Scopus subject areas
- Physiology
- Cardiology and Cardiovascular Medicine
- Physiology (medical)