A new middle cerebral artery occlusion model for intra-arterial drug infusion in rats

The transient intraluminal filament Middle Cerebral Artery Occlusion stroke model in rats. A step by step guide and technical considerations

OBJECTIVE

Stroke is a leading cause of disability and mortality worldwide. Related research, although already providing significant insights on the underlying pathophysiology and potential treatment strategies, is far from conclusive. In this respect, stroke models are proving of extreme significance for laboratories around the world. The scope of this article is to present in detail the most popular to date focal stroke model, the tifMCAO model in rats. This model mimics reliably stroke in humans and also approximates endovascular thrombectomy.

METHODS

The tifMCAO model was performed on Wistar rats with a weight of 300-400 gr. The surgical technique is described in a step-wise manner, while pictures and/or HD video accompany each step. Complete arteriotomy of the ECA stump is introduced during the procedure.

RESULTS

We performed the tifMCAO in 65 rats (male and female) involved in various experimental protocols. Although that initial mortality was 48%, practice reduced this number to10%. The mean procedural time was 53 min (range, 38 - 85 min). Stroke was confirmed in 87.5% of the cases.

CONCLUSIONS

The tifMCAO stroke model in rats is the most commonly utilized experimental model of focal ischemia because of its clinical relevance. We revisited the procedure and divided it, for instructional purposes, in 15 consecutive distinct steps.

An Optimal Animal Model of Ischemic Stroke Established by Digital Subtraction Angiography-Guided Autologous Thrombi in Cynomolgus Monkeys

Objective

Ischemic stroke seriously threatens human health, characterized by the high rates of incidence, disability, and death. Developing a reliable animal model that mimics most of the features of stroke is critical for pathological studies and clinical research. In this study, we aimed to establish and examine a model of middle cerebral artery occlusion (MCAO) guided by digital subtraction angiography (DSA) in cynomolgus monkeys.

Materials and Methods

In this study, 15 adult male cynomolgus monkeys were enrolled. Under the guidance of DSA, a MCAO model was established by injecting an autologous venous clot into the middle cerebral artery (MCA) via femoral artery catheter. Thrombolytic therapy with alteplase (rt-PA) was given to eight of these monkeys at 3 h after the occlusion. Blood test and imaging examination, such as computed tomography angiography (CTA), CT perfusion (CTP), brain magnetic resonance imaging (MRI), and brain magnetic resonance angiography (MRA), were performed after the operation to identify the post-infarction changes. The behavioral performance of cynomolgus monkeys was continuously observed for 7 days after operation. The animals were eunthanized on the 8th day after operation, and then the brain tissues of monkeys were taken for triphenyltetrazolium chloride (TTC) staining.

Results

Among the 15 cynomolgus monkeys, 12 of them were successfully modeled, as confirmed by the imaging findings and staining assessment. One monkey died of brain hernia resulted from intracranial hemorrhage confirmed by necropsy. DSA, CTA, and MRA indicated the presence of an arterial occlusion. CTP and MRI showed acute focal cerebral ischemia. TTC staining revealed infarct lesions formed in the brain tissues.

Conclusion

Our study may provide an optimal non-human primate model for an in-depth study of the pathogenesis and treatment of focal cerebral ischemia.

Intra-arterial human urinary kallidinogenase alleviates brain injury in rats with permanent middle cerebral artery occlusion through PI3K/AKT/FoxO1 signaling pathway

An urgent need exists to develop intra-arterial treatment for acute ischemic stroke in animal study. This study aimed to explore the beneficial effects of intra-arterial administration of human urinary kallidinogenase (HUK) on brain injury after permanent middle cerebral artery occlusion (pMCAO) in a rat model, and the potential underlying molecular mechanisms. Brain injury induced by pMCAO was evaluated through measuring neurological deficit scores, neuropathological changes, and inflammatory factors. Neurological deficits were observed 24 h after pMCAO and were alleviated by intra-arterial HUK treatment obviously. Inhibition of PI3K by LY294002 blocked the beneficial effect of HUK on neurological functions. In contrast to the pMCAO group, the intra-arterial HUK treatment group showed relatively more regularly arranged neurons and fewer pyknosis. Neurodegeneration, necrosis, infarct area and markers for brain injury were all ameliorated by intra-arterial HUK treatment. Moreover, a lower expression of inflammatory factors including interleukin (IL)-1β, IL-6, and tumor necrosis factor (TNF)-α, and a higher expression of IL-10 were observed in the intra-arterial HUK treatment group than that in the pMCAO group. Additionally, when comparing with pMCAO group, a lower level of caspase-3, bax, and apoptotic rate, and a higher level of bcl-2, p-PI3K, p-AKT and p-FoxO1were observed in the pMCAO + HUK group. These results suggest that intra-arterial administration of HUK is a promising therapeutic strategy against pMCAO induced brain injury, and PI3K/AKT/FoxO1 signaling pathway may be involved in this process.