title: Response of mouse brain perfusion to hypo- and hyperventilation measured by arterial spin labeling.
abstract: We aimed to setup a noninvasive and well-controlled methodology for evaluation of the cerebrovascular response in mice (C57BL/6J; 12 weeks). Therefore we applied a normo-, hypo-, and hyperventilation paradigm combined with arterial spin labeling and monitoring of the expired CO(2) (expCO(2)) (n=7) or arterial pCO(2) (apCO(2)) (n=12). Reducing the tidal volume by 25% and the respiratory rate by 20% resulted in hypercapnia (apCO(2) from 33 ± 6 mmHg to 64 ± 16 mmHg). Increasing the respiratory rate by 25% and the tidal volume by 20% decreased apCO(2) to 22 ± 5 mmHg. Cerebral blood flow (CBF) was 82 ± 21, 163 ± 41 and 64 ± 18 mL/100 g/min during normo, hypo-, and hyperventilation, respectively (midbrain). The correlation of apCO(2) and CBF levels resulted in a cerebrovascular response of 2.7 ± 0.3, 2.1 ± 0.3, 2.1 ± 0.3, and 3.7 ± 0.5 mL/100 g/min/mmHg for midbrain, cortex, hippocampus and thalamus, respectively. As expCO(2) levels were correlated with apCO(2) (r(2)=0.86; n=4) and CBF (r(2)=0.67) a cerebrovascular response based on simultaneously recorded CBF and expCO(2) levels could be derived (3.3 ± 0.5, 2.5 ± 0.4, 3.0 ± 0.4, and 4.5 ± 0.6 mL/100 g/min/mmHg; order as above). A cross-over experiment resulted in similar responses. In conclusion, this protocol allows evaluating basal CBF and cerebrovascular response in mice under well-controlled conditions by simply changing ventilator settings and correlating CBF with apCO(2) and/or simultaneously obtained expCO(2).
authors: Department of Cardiovascular Diseases, Division of Experimental Cardiac Surgery, K.U.Leuven, Belgium. wouter.oosterlinck@med.kuleuven.be
authors: W Wouter
authors: WW
authors: Oosterlinck
authors: T
authors: T
authors: Dresselaers
authors: V
authors: V
authors: Geldhof
authors: A
authors: A
authors: Van Santvoort
authors: W
authors: W
authors: Robberecht
authors: P
authors: P
authors: Herijgers
authors: U
authors: U
authors: Himmelreich
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D001783:Blood Flow Velocity; D001784:Blood Gas Analysis; D001921:Brain / Q000098:blood supply* / Q000503:physiopathology*; D002560:Cerebrovascular Circulation; D018592:Cross-Over Studies; D006935:Hypercapnia / Q000503:physiopathology*; D006985:Hyperventilation / Q000503:physiopathology*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000295:instrumentation / Q000379:methods*; D051379:Mice; D008810:Mice, Inbred C57BL; D013113:Spin Labels
chemical_list: D013113:Spin Labels