Remote Limb Ischemic Conditioning during Cerebral Ischemia Reduces Infarct Size through Enhanced Collateral Circulation in Murine Focal Cerebral Ischemia.

Abstract

BACKGROUND:

Remote ischemic conditioning (RIC) induces protection in focal cerebral ischemia. The conditioning is divided into pre-, per-, and postconditioning. However, the mechanisms of RIC remain unknown.

OBJECTIVES:

This study aimed to determine the most effective subtype of RIC. We also examined involvement of collateral circulation on RIC.

METHODS:

Transient middle cerebral artery occlusion (MCAO) was performed with nylon sutures in adult C57BL/6 mice under the monitoring of cerebral blood flow (CBF). Fifty mice were divided into 5 groups: MCAO control group, delayed pre-RIC group (RIC 24 hours before MCAO), early pre-RIC group (RIC 5 minutes before MCAO), per-RIC group (RIC during MCAO), and post-RIC group (RIC 5 minutes after MCAO). In other middle cerebral artery (MCA) control and per-RIC groups, collateral circulation was visualized with latex compound perfusion.

RESULTS:

After MCAO, CBF was reduced by 80% in all groups. At the end of MCAO, relative increase in CBF in per-RIC group was significantly greater than that in MCA control, whereas the infarct volume in per-RIC group was significantly smaller than that in other groups. The diameter of leptomeningeal anastomosis was larger in the per-RIC group than that in the control group.

CONCLUSIONS:

Among the 4 RIC procedures, only the per-RIC group showed clear brain protection. Enhancement of collateral circulation could play a role in the protective effect of per-RIC.

• Authors: Kazuo Kitagawa, Moeko Saitoh, Kentaro Ishizuka, Satoru Shimizu
• Journal: Journal of stroke and cerebrovascular diseases : the official journal of National Stroke Association (J Stroke Cerebrovasc Dis) Vol. 27 Issue 4 Pg. 831-838 (Apr 2018) ISSN: 1532-8511 [Electronic] United States
• PMID: 29395650 (Publication Type: Journal Article)
• Copyright: Copyright © 2018 National Stroke Association. Published by Elsevier Inc. All rights reserved.

Topics

• Animals
• Behavior, Animal
• Blood Flow Velocity
• Brain (pathology, physiopathology)
• Cerebrovascular Circulation
• Collateral Circulation
• Disease Models, Animal
• Hindlimb (blood supply)
• Infarction, Middle Cerebral Artery (complications, pathology, physiopathology, therapy)
• Ischemic Preconditioning (methods)
• Male
• Mice, Inbred C57BL
• Motor Activity
• Regional Blood Flow
• Time Factors