Increased pressure during retrograde cerebral perfusion provides better preservation of the Na+, K+-ATPase activity.
This study was carried out to determine if increased perfusion pressure during retrograde cerebral perfusion (RCP) provides better preservation of the brain Na+, K+-ATPase activity. Twenty pigs were subjected to anesthesia alone (control group, n=5), hypothermic circulatory arrest (HCA) (HCA group, n = 5), HCA+RCP at perfusion pressures of 24-29 mmHg (Low-pressure group, n=5), or HCA+RCP at perfusion pressures of 34-40 mmHg (High-pressure group, n = 5). The brain was harvested for the measurement of tissue Na+, K+-ATPase activity. Relative to the control pigs (67.2 +/- 2.1%), significant impairment of Na+, K+-ATPase activity was observed in all three experimental groups (29.8 +/- 7.4% in HCA group, 33.5 +/- 2.9% in the Low-pressure group, and 52.0 +/- 1.8% in the High-pressure group, p < 0.01). The best preservation of the enzyme, particularly in the cortex and cerebellum regions, was observed in the High-pressure group (p < 0.01). In conclusion, HCA causes severe impairment of Na+, K+-ATPase activity, and increasing perfusion pressures from 24-29 to 34-40 mmHg during RCP significantly improves preservation of Na+, K+-ATPase activity, and the improvement of the protection varies in different regions of the brain.
Yang
Luojia
L
University of Manitoba, Winnipeg, Canada.
Li
Zhijun
Z
Yang
Yanmin
Y
Zhu
Raymound
R
Summers
Randy
R
Deslauriers
Roxanne
R
Ye
Jian
J
D000758:Anesthesia; D000818:Animals; D001921:Brain / Q000098:blood supply* / Q000201:enzymology*; D002315:Cardiopulmonary Bypass / Q000379:methods*; D002560:Cerebrovascular Circulation; D007036:Hypothermia, Induced; D010100:Oxygen / Q000378:metabolism; D011312:Pressure; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism*; D013552:Swine
D000254:Sodium-Potassium-Exchanging ATPase; D010100:Oxygen