C-Y Kim1, S H Paek, B G Seo, J H Kim, D H Han. 1. Department of Neurosurgery, College of Medicine and Neuroscience Research Institute, Medical Research Center, Seoul National University, Seoul National University Hospital, Seoul, Korea. cykim69@snu.ac.kr
Abstract
BACKGROUND: This study aimed to clarify the characteristics of the basilar arteries of rabbits two and seven days after subarachnoid haemorrhage (SAH) and to investigate the influence of hypoxia on vascular responses to acetylcholine and endothelin-1. METHODS: Thirty four New Zealand white rabbits were divided into 3 groups: 1) control (n=6), 2) 2 days post SAH (n=15), and 3) 7 days post SAH (n=13). Rabbits in the groups 2 and 3 underwent vertebral angiography before sacrifice. Harvested vascular rings were suspended in a small vessel myograph system for isometric tension recording in response to vasodilatory and vasoconstrictory stimulation in oxygenated (95% O2/5% CO2) and hypoxic (95% N2/5% CO2) conditions. To investigate the response to a vasodilator, acetylcholine (ACh) (10(-7) to 3 x 10(-4) M) was applied to a basilar artery pre-contracted with histamine (10(-6) approximately 10(-5) M). To investigate the response to a vasoconstrictor, the effect of endothelin-1 (ET-1) (10(-11) to 3 x 10(-8) M) was observed in quiescent rings. FINDINGS: Seven of 15 rabbits that underwent angiography two days after operation showed vasospasm to 64.3+/-11.2% of the original diameter; likewise seven of the 13 rabbits studied seven days after operation showed vasospasm to 64.9+/-10.9% of the original diameter. Hypoxic conditions significantly reduced the relaxation response to ACh but did not influence basilar artery contraction to ET-1. Responses to ACh and ET-1 did not differ significantly in vessels from animals with or without vasospasm at 2 days. In contrast, at 7 days vascular responses to ACh and ET-1 were significantly less in vessels from animals with vasospasm than those without (p=0.029, 0.032), and also less than in vessels from animals with vasospasm at day 2 (p=0.002, 0.004). There was not a significant difference in the vascular responses of basilar arteries from animals without vasospasm. INTERPRETATION: The markedly lower vascular responses of basilar arteries of rabbits to ACh and ET-1 found seven days after SAH may relate to delayed vasospasm in patients with SAH.
BACKGROUND: This study aimed to clarify the characteristics of the basilar arteries of rabbits two and seven days after subarachnoid haemorrhage (SAH) and to investigate the influence of hypoxia on vascular responses to acetylcholine and endothelin-1. METHODS: Thirty four New Zealand white rabbits were divided into 3 groups: 1) control (n=6), 2) 2 days post SAH (n=15), and 3) 7 days post SAH (n=13). Rabbits in the groups 2 and 3 underwent vertebral angiography before sacrifice. Harvested vascular rings were suspended in a small vessel myograph system for isometric tension recording in response to vasodilatory and vasoconstrictory stimulation in oxygenated (95% O2/5% CO2) and hypoxic (95% N2/5% CO2) conditions. To investigate the response to a vasodilator, acetylcholine (ACh) (10(-7) to 3 x 10(-4) M) was applied to a basilar artery pre-contracted with histamine (10(-6) approximately 10(-5) M). To investigate the response to a vasoconstrictor, the effect of endothelin-1 (ET-1) (10(-11) to 3 x 10(-8) M) was observed in quiescent rings. FINDINGS: Seven of 15 rabbits that underwent angiography two days after operation showed vasospasm to 64.3+/-11.2% of the original diameter; likewise seven of the 13 rabbits studied seven days after operation showed vasospasm to 64.9+/-10.9% of the original diameter. Hypoxic conditions significantly reduced the relaxation response to ACh but did not influence basilar artery contraction to ET-1. Responses to ACh and ET-1 did not differ significantly in vessels from animals with or without vasospasm at 2 days. In contrast, at 7 days vascular responses to ACh and ET-1 were significantly less in vessels from animals with vasospasm than those without (p=0.029, 0.032), and also less than in vessels from animals with vasospasm at day 2 (p=0.002, 0.004). There was not a significant difference in the vascular responses of basilar arteries from animals without vasospasm. INTERPRETATION: The markedly lower vascular responses of basilar arteries of rabbits to ACh and ET-1 found seven days after SAH may relate to delayed vasospasm in patients with SAH.
Authors: Mauro Oddo; Daniele Poole; Raimund Helbok; Geert Meyfroidt; Nino Stocchetti; Pierre Bouzat; Maurizio Cecconi; Thomas Geeraerts; Ignacio Martin-Loeches; Hervé Quintard; Fabio Silvio Taccone; Romergryko G Geocadin; Claude Hemphill; Carole Ichai; David Menon; Jean-François Payen; Anders Perner; Martin Smith; José Suarez; Walter Videtta; Elisa R Zanier; Giuseppe Citerio Journal: Intensive Care Med Date: 2018-03-02 Impact factor: 17.440
Authors: Stefan Wanderer; Basil E Grüter; Fabio Strange; Sivani Sivanrupan; Stefano Di Santo; Hans Rudolf Widmer; Javier Fandino; Serge Marbacher; Lukas Andereggen Journal: Brain Sci Date: 2020-03-07