Focal Cerebral Ischemia Model by Endovascular Suture Occlusion of the Middle Cerebral Artery in the Rat

Abstract

Stroke is the leading cause of disability and the third leading cause of death in adults worldwide 1 . In human stroke, there exists a highly variable clinical state; in the development of animal models of focal ischemia, however, achieving reproducibility of experimentally induced infarct volume is essential. The rat is a widely used animal model for stroke due to its relatively low animal husbandry costs and to the similarity of its cranial circulation to that of humans 2,3 . In humans, the middle cerebral artery (MCA) is most commonly affected in stroke syndromes and multiple methods of MCA occlusion (MCAO) have been described to mimic this clinical syndrome in animal models. Because recanalization commonly occurs following an acute stroke in the human, reperfusion after a period of occlusion has been included in many of these models. In this video, we demonstrate the transient endovascular suture MCAO model in the spontaneously hypertensive rat (SHR). A filament with a silicon tip coating is placed intraluminally at the MCA origin for 60 minutes, followed by reperfusion. Note that the optimal occlusion period may vary in other rat strains, such as Wistar or Sprague-Dawley. Several behavioral indicators of stroke in the rat are shown. Focal ischemia is confirmed using T2-weighted magnetic resonance images and by staining brain sections with 2,3,5-triphenyltetrazolium chloride (TTC) 24 hours after MCAO. Video LinkThe video component of this article can be found at https://www.jove.com/video/1978/ Protocol MCAO Rat Model Presurgical PreparationsAseptic technique should be used for all survival surgical procedures. Disinfect the surgical work surface with commercial disinfectant and prepare sterile surgical packs of instruments, drapes, gauze, swabs, sutures, and scalpel blades by autoclaving. A surgical mask, hair bonnet and sterile gloves should be worn. A Germinator dry bead sterilizer is also used to resterilize surgical instruments between procedures if multiple rat surgeries will be done during one session. Prewarm a water-jacketed homeothermic blanket and place under an absorbent pad in order to prevent hypothermia of the rat during surgery.1. Place spontaneously hypertensive rat (or other rat strain of choice) into an induction chamber and induce anesthesia with 5% isoflurane (anesthesia machine should be set to 1.0 L/min O 2 and 1.0 L/min N 2 O). Lower to 1-2% isoflurane to maintain anesthesia. 2. Apply Artificial Tears ointment to both eyes. 3. Shave the throat and left neck region beyond the prospective incision site using clippers (Oster A5 with #10 blade). 4. Apply Betadine to a gauze pad and disinfect the skin starting from the center of the surgical region, spiraling outward. Rinse with sterile gauze pad containing 70% ethanol, moving pad in a similar pattern. Repeat both steps for a total of three cycles. 5. Inject 0.2 mL of 0.5% bupivacaine subcutaneously along the prospective incision site. 6. Place rat in sterile stockinette or cover with a sterile surgical drape.

Protective Role of Xinnaoning Tablet in Ischemic Stroke in Rat Model

“…To confirm our speculation, we first created the cerebral ischemia rats model from different groups by using methods as previously described (Uluc et al, 2011). Based on analysis the LD and LDH level in the brain tissue, the ischemia group demonstrated increased level of LD from 0.336 mmol/L to 0.49 mmol/L ( Table 1), which suggesting the less oxygen supply for the brain tissue.…”

“…Starting from the sixth day of Xinnaoning administration, only water was used to feed rats. In the seventh days, one hour after administration of Xinnaoning, the focal cerebral ischemia model by endovascular suture occlusion was conducted as previously described (Uluc et al, 2011). Then the brain tissue of rats were removed and homogenized with PBS at a ratio of 1 to 9 for further tests.…”

Improved Rat Stroke Model by Intraluminal Middle Cerebral Artery Occlusion: A Special Emphasis on Surgical Technique

“…The first model for ischemic stroke was developed in rats by Koizumi et al in 1986 by intraluminal MCAO [4]. Several optimised models for MCAO in rats were described [5], [6]; in order to minimize intra-and perioperative complications. Thus, we validated this experimental model in our laboratory by establishing the concordance between morphological modifications and ischemic tissue volume measured by MRI.…”

“…The most used models for focal cerebral ischemia is MCAO method using a specially manufactured monofilament thread with a silicone tip which is passed through the internal carotid artery (ICA) until the silicone tip reaches the origin of the middle cerebral artery (MCA) thus occluding it [6]. For our research, we used a reusable silicon rubber-coated monofilament, size 4-0, diameter 0.185 mm with a coating diameter of 0.39 +/-0.02 mm (Doccol Corporation, USA).…”

Monitoring ischemic cerebral injury in spontaneously hypertensive rats by diffusion tensor imaging

“…Spontaneously hypertensive rats (SHR/NCrl) were obtained from Charles Rivers Laboratories (Wilmington, MA, USA). MCAO surgery was performed similarly to that described previously (33,60). Rats were anesthetized with isoflurane and the presumptive incision area was shaved and disinfected with Betadine, prior to administration of 0.2 ml 0.5% bupivacaine for local analgesia.…”