| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1994956 | Microvascular Research | 2011 | 7 Pages |
AimThis study was performed: 1) to assess the relationship between blood flow velocity in the internal carotid artery (CBFICA) and pial artery pulsation (cc-TQ) and 2) to evaluate flow-induced changes in pial artery compliance.MethodsExperiments were performed on 10 crossbred male rabbits. Heart rate (HR), blood pressure (BP), left ventricle ejection fraction (LVEF), CBFICA, the systolic–diastolic blood volume fraction in the brain circulation (CBFSDF) and cc-TQ were recorded after glucagon and acetazolamide administration. cc-TQ was measured with near-infrared transillumination back scattering sounding (NIR-T/BSS), LVEF and CBFSDF with gated scintigraphy and BP and CBFICA with electromagnetic pressure and flow transducers, respectively. Doses of drugs were chosen to exert a haemodynamic effect but not change BP or intracranial pressure.ResultsAcetazolamide and glucagon evoked significant increases in cc-TQ, CBFSDF, CBFICA, LVEF and HR. The following interdependencies were found: 1) changes after acetazolamide administration compared to baseline: CBFSDF vs. LVEF (r = 0.73, p < 0.05), cc-TQ vs. CBFSDF (r = − 0.67, p < 0.05), cc-TQ vs. LVEF (r = − 0.76, p < 0.05), 2) changes after glucagon administration compared to baseline: CBFICA vs. BP (r = 0.73, p < 0.05), CBFSDF vs. LVEF (r = 0.87, p < 0.05), cc-TQ vs. HR (r = 0.85, p < 0.05), cc-TQ vs. CBFICA (r = − 0.74, p < 0.05).ConclusionIn the absence of systemic BP changes, pial arteries are significantly affected by changes in CBFICA. Pial arteries counteract changes in CBFICA and CBFSDF. The ability of pial arteries to stabilise CBFICA is impaired after acetazolamide administration. Changes in cardiac output directly affect the brain's microcirculation. NIR-T/BSS recordings allow for non-invasive assessment of changes in pial artery compliance.
Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Changes in carotid blood flow velocity affect the brain microcirculation. ► Pial arteries tend to stabilise changes in cerebral blood flow velocity. ► Acetazolamide impairs the ability of pial arteries to stabilise cerebral blood flow. ► Changes in cardiac output, directly affect the brain's microcirculation. ► NIR-T/BSS allows for the non-invasive assessment of changes in pial artery compliance.
