Abstract
Previous studies have demonstrated a significant pressure gradient from carotid artery to pial or middle cerebral arteries. This pressure gradient suggests that large cerebral arteries contribute to cerebral resistance. We have tested the hypothesis that large cerebral arteries contribute to regulation of cerebral blood flow during changes in blood gases and arterial pressure. Microspheres were used to measure brain blood flow in anesthetized dogs. Resistance of large cerebral arteries was estimated by determining the pressure gradient between common carotid and wedged vertebral artery catheters. Systemic hypercapnia and hypoxia dilated large cerebral arteries, and hypocapnia constricted large cerebral arteries. Resistance of large arteries was 0.6±0.1 (mean ± SE) mm Hg per ml/min per 100 g during normocapnia. During hypercapnia and hypoxia, large artery resistance decreased significantly to 0.2 ± 0.03 and 0.3 ± 0.05, respectively. During hypocapnia large artery resistance increased significantly to 1.0 ± 0.1. In other experiments, we found that large cerebral arteries participate in auto-regulatory responses to hemorrhagic hypotension. When arterial pressure was reduced from 110 to 58 mm Hg, autoregulation maintained cerebral blood flow constant, and resistance of large cerebral arteries decreased significantly from 1.0 ± 0.2 to 0.6 ± 0.1 mm Hg per ml/min per 100 g. In absolute terms, we calculated that 20-45% of the change in total cerebral resistance during these interventions was accounted for by changes in large artery resistance. These studies indicate that large cerebral arteries, as well as arterioles, participate actively in regulation of cerebral blood flow during changes in arterial blood gases and during autoregulatory responses to hemorrhagic hypotension.
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- Abboud F. M., Eckstein J. W. Comparative changes in segmental vascular resistance in response to nerve stimulation and to norepinephrine. Circ Res. 1966 Mar;18(3):263–277. doi: 10.1161/01.res.18.3.263. [DOI] [PubMed] [Google Scholar]
- Abboud F. M. Vascular responses to norepinephrine, angiotensin, vasopressin and serotonin. Fed Proc. 1968 Nov-Dec;27(6):1391–1395. [PubMed] [Google Scholar]
- BAKAY L., SWEET W. H. Cervical and intracranial intra-arterial pressures with and without vascular occlusion. Surg Gynecol Obstet. 1952 Jul;95(1):67–75. [PubMed] [Google Scholar]
- Borrás A., Méndez M. S., Martínez A. Ophthalmic-brachial artery pressure ratio in man. Am J Ophthalmol. 1969 May;67(5):684–688. doi: 10.1016/s0002-9394(69)90991-x. [DOI] [PubMed] [Google Scholar]
- Du Boulay G., Edmonds-Seal J., Bostick T. The effect of intermittent positive pressure ventilation upon the calibre of cerebral arteries in spasm following subarachnoid haemorrhage--a preliminary communication. Br J Radiol. 1968 Jan;41(481):46–48. doi: 10.1259/0007-1285-41-481-46. [DOI] [PubMed] [Google Scholar]
- Endo M., Hirosawa K., Kaneko N., Hase K., Inoue Y. Prinzmetal's variant angina. Coronary arteriogram and left ventriculogram during angina attack induced by methacholine. N Engl J Med. 1976 Jan 29;294(5):252–255. doi: 10.1056/NEJM197601292940505. [DOI] [PubMed] [Google Scholar]
- Fukasawa H. Hemodynamical studies of cerebral arteries by means of mathematical analysis of arterial casts. Tohoku J Exp Med. 1969 Nov;99(3):255–268. doi: 10.1620/tjem.99.255. [DOI] [PubMed] [Google Scholar]
- Greenfield J. C., Jr, Tindall G. T. Effect of norepinephrine, epinephrine, and angiotensin on blood flow in the internal carotid artery of man. J Clin Invest. 1968 Jul;47(7):1672–1684. doi: 10.1172/JCI105858. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Grimson B. S., Robinson S. C., Danford E. T., Tindall G. T., Greenfield J. C., Jr Effect of serotonin on internal and external carotid artery blood flow in the baboon. Am J Physiol. 1969 Jan;216(1):50–55. doi: 10.1152/ajplegacy.1969.216.1.50. [DOI] [PubMed] [Google Scholar]
- Heistad D. D., Abbound F. M., Eckstein J. W. Vasoconstrictor response to simulated diving in man. J Appl Physiol. 1968 Nov;25(5):542–549. doi: 10.1152/jappl.1968.25.5.542. [DOI] [PubMed] [Google Scholar]
- Heistad D. D., Marcus M. L., Ehrhardt J. C., Abboud F. M. Effect of stimulation of carotid chemoreceptors on total and regional cerebral blood flow. Circ Res. 1976 Jan;38(1):20–25. doi: 10.1161/01.res.38.1.20. [DOI] [PubMed] [Google Scholar]
- Heistad D. D., Marcus M. L., Sandberg S., Abboud F. M. Effect of sympathetic nerve stimulation on cerebral blood flow and on large cerebral arteries of dogs. Circ Res. 1977 Sep;41(3):342–350. doi: 10.1161/01.res.41.3.342. [DOI] [PubMed] [Google Scholar]
- Heistad D. D., Marcus M. L. Total and regional cerebral blood flow during stimulation of carotid baroreceptors. Stroke. 1976 May-Jun;7(3):239–243. doi: 10.1161/01.str.7.3.239. [DOI] [PubMed] [Google Scholar]
- Kontos H. A., Wei E. P., Raper A. J., Patterson J. L., Jr Local mechanism of CO2 action of cat pial arterioles. Stroke. 1977 Mar-Apr;8(2):226–229. doi: 10.1161/01.str.8.2.226. [DOI] [PubMed] [Google Scholar]
- Magun J. G. The effect of pharmacologically increased blood pressure on brain circulation. Angiographic investigation of arterial diameter and blood flow in patients with normal and pathological angiograms. Z Neurol. 1973 Apr 2;204(2):107–134. doi: 10.1007/BF00315937. [DOI] [PubMed] [Google Scholar]
- Rudolph A. M., Heymann M. A. The circulation of the fetus in utero. Methods for studying distribution of blood flow, cardiac output and organ blood flow. Circ Res. 1967 Aug;21(2):163–184. doi: 10.1161/01.res.21.2.163. [DOI] [PubMed] [Google Scholar]
- SHULMAN K. SMALL ARTERY AND VEIN PRESSURES IN THE SUBARACHNOID SPACE OF THE DOG. J Surg Res. 1965 Feb;5:56–61. doi: 10.1016/s0022-4804(65)80067-1. [DOI] [PubMed] [Google Scholar]
- Shapiro H. M., Stromberg D. D., Lee D. R., Wiederhielm C. A. Dynamic pressures in the pial arterial microcirculation. Am J Physiol. 1971 Jul;221(1):279–283. doi: 10.1152/ajplegacy.1971.221.1.279. [DOI] [PubMed] [Google Scholar]
- Stromberg D. D., Fox J. R. Pressures in the pial arterial microcirculation of the cat during changes in systemic arterial blood pressure. Circ Res. 1972 Aug;31(2):229–239. doi: 10.1161/01.res.31.2.229. [DOI] [PubMed] [Google Scholar]
- Symon L. A comparative study of middle cerebral pressure in dogs and macaques. J Physiol. 1967 Aug;191(3):449–465. doi: 10.1113/jphysiol.1967.sp008261. [DOI] [PMC free article] [PubMed] [Google Scholar]