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Partial Carotid Ligation Impairs Middle Cerebral Artery Endothelial Function in Old Mice
Author(s) -
Reihl Kelly,
Walker Ashley,
Donato Anthony,
Lesniewski Lisa
Publication year - 2015
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.29.1_supplement.949.1
Subject(s) - ligation , medicine , middle cerebral artery , occlusion , cardiology , cerebral arteries , cerebral blood flow , transcranial doppler , common carotid artery , perfusion , anesthesia , carotid arteries , ischemia
Previous findings suggest that old mice have greater impairments in cerebral perfusion following internal carotid artery (ICA) occlusion than young mice. However, it is unknown if ICA occlusion affects endothelial function in its major downstream branch, the middle cerebral artery (MCA), in old mice. We performed partial ligation (including full ICA ligation) in the left carotid arteries of old B6D2F1 mice (29±1 mo, n=5) and then tested endothelium‐dependent dilation (EDD) of both left and right MCAs at 8 days post‐ligation. Doppler ultrasound of the left carotid artery confirmed the efficacy of partial ligation, demonstrating a 55% reduction in antegrade (p=0.02) and 110% increase in retrograde (p=0.03) blood flow that resulted in a 340% increase in oscillatory index (p=0.001) at 7 days post‐ligation compared with baseline. There were no changes in blood flow or oscillatory index in the non‐ligated right carotid artery (p>0.05). Maximal EDD was 23% lower in the left MCA compared with the right MCA (30±4% vs. 39±5%, p=0.02). After incubation with the nitric oxide (NO) synthase inhibitor, L‐NAME, maximal EDD did not differ between the left and right MCA (9±8% vs. 8±7%, p=0.47), indicating that impaired EDD in the left MCA was mediated by reduced NO bioavailability. There was no difference between the left and right MCA in the maximal response to endothelium‐independent dilation (83±2% vs. 80±4%, p=0.21). These results demonstrate that partial carotid ligation leads to impaired endothelial function of the ipsilateral MCA in old mice and may explain the impairments in cerebral perfusion following ICA occlusion.