Delayed hypovolemic hypotension exacerbates the hemodynamic and histopathologic consequences of thromboembolic stroke in rats

W. Dalton Dietrich, Ricardo Prado, Cristina Pravia, Weizhao Zhao, Myron D. Ginsberg, Brant D. Watson

Research output: Contribution to journalArticle

11 Scopus citations

Abstract

Abnormalities in cerebrovascular reactivity or hemodynamic reserve are risk factors for stroke. The authors determined whether hemodynamic reserve is reduced in an experimental model of thromboembolic stroke. Nonocclusive common carotid artery thrombosis (CCAT) was produced in rats by a rose bengal-mediated photochemical insult, and moderate hypotension (60 mm Hg/30 min) was induced 1 hour later by hemorrhage. Alterations in local cerebral blood flow (1CBF) were assessed immediately after the hypotensive period by 14C-iodoantipyrine autoradiography, and histopathologic outcome was determined 3 days after CCAT. Compared to normotensive CCAT rats (n = 5), induced hypotension after CCAT (n = 7) led to enlarged regions of severe ischemia (i.e., mean 1CBF < 0.24 mL/g/min) in the ipsilateral hemisphere. For example, induced hypotension increased the volume of severely ischemic sites from 16 ± 4 mm3 (mean ± SD) to 126 ± 99 mm3 (P < 0.05). Histopathologic data also showed a larger volume of ischemic damage with secondary hypotension (n = 7) compared to normotension (22 ± 15 mm3 versus 5 ± 5 mm3, P < .05). Both hypotension-induced decreases in 1CBF and ischemic pathology were commonly detected within cortical anterior and posterior borderzone areas and within the ipsilateral striatum and hippocampus. In contrast to CCAT, mechanical ligation of the common carotid artery plus hypotension (n = 8) did not produce significant histopathologic damage. Nonocclusive CCAT with secondary hypotension therefore predisposes the post- thrombotic brain to hemodynamic stress and structural damage.

Original languageEnglish (US)
Pages (from-to)918-926
Number of pages9
JournalJournal of Cerebral Blood Flow and Metabolism
Volume19
Issue number8
DOIs
StatePublished - Jan 1 1999

Keywords

  • Autoregulation
  • Cerebral blood flow
  • Embolic stroke
  • Platelets
  • Thrombosis

ASJC Scopus subject areas

  • Endocrinology
  • Neuroscience(all)
  • Endocrinology, Diabetes and Metabolism

Fingerprint Dive into the research topics of 'Delayed hypovolemic hypotension exacerbates the hemodynamic and histopathologic consequences of thromboembolic stroke in rats'. Together they form a unique fingerprint.

  • Cite this