Dually supplied t-junctions in arteriolo-arteriolar anastomosis in mice: Key to local hemodynamic homeostasis in normal and ischemic states?

Haruki Toriumi, Jemal Tatarishvili, Minoru Tomita, Yutaka Tomita, Miyuki Unekawa, Norihiro Suzuki

Research output: Contribution to journalArticlepeer-review

38 Citations (Scopus)

Abstract

Background and Purpose-: The functional role of arteriolo-arteriolar anastomosis (AAA) between the middle cerebral artery (MCA) and anterior cerebral artery in local hemodynamics is unknown, and was investigated here. Methods-: Blood flow in AAAs was examined using fluorescein isothiocyanate-labeled red blood cells (RBCs) as a flow indicator in 16 anesthetized C57BL/6J mice before and after MCA occlusion up to 7 experimental days. Results-: We observed paradoxical flow in AAAs; labeled RBCs entered from both the MCA and anterior cerebral artery sides and the opposing flows met at a branching T-junction, where the flows combined and passed into a penetrating arteriole. The dually fed T-junction was not fixed in position, but functionally jumped to adjacent T-junctions in response to changing hemodynamic conditions. On MCA occlusion, RBC flow from the MCA side immediately stopped. After a period of "hesitation," blood started to move retrogradely in one of the MCA branches toward the MCA stem. The retrograde blood flow was statistically significantly (P<0.05), serving to feed blood to other MCA branches after a lag period. In capillaries, MCA occlusion induced immediate RBC disappearance in the ischemic core and to a lesser extent in the marginal zone near AAAs. At day 3 after ischemia, we recognized the beginning of remodeling with angiogenesis centering on AAAs. Conclusions-: AAAs appear to play a key role in local hemodynamic homeostasis, both in the normal state and in the development of collateral channels and revascularization during ischemia.

Original languageEnglish
Pages (from-to)3378-3383
Number of pages6
JournalStroke
Volume40
Issue number10
DOIs
Publication statusPublished - 2009 Oct

Keywords

  • Angiogenesis
  • Arterio-arterial anastomosis
  • Cerebral ischemia
  • Penumbra
  • Red blood cell

ASJC Scopus subject areas

  • Clinical Neurology
  • Cardiology and Cardiovascular Medicine
  • Advanced and Specialised Nursing

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