Spinal Cord Blood Flow after Ischemic Preconditioning in a Rat Model of Spinal Cord Ischemia

Abstract

Spinal cord blood flow after ischemic preconditioning is poorly characterized. This study is designed to evaluate spinal cord blood flow patterns in animals after acute ischemic preconditioning. Experiment 1: After a laminectomy and placement of a laser Doppler probe over the lumbar spinal cord to measure spinal cord blood flow, 16 male Sprague-Dawley rats were randomized into two groups: ischemic preconditioning (IPC, n = 8), and control (CTRL, n = 8). Rats in the CTRL and the IPC groups were subjected to 12 min of ischemia directly followed by 60 min of reperfusion. IPC rats received 3 min of IPC and 30 min of reperfusion prior to the 12-min insult period. Experiment 2: After instrumentation, the rats were randomized into three groups: control (CTRL, n = 7), ischemic preconditioning (IPC, n = 7), and time control (TC, n = 4). Rats in the CTRL and the IPC groups were subjected to the same ischemia and reperfusion protocol as above. The TC group was anesthetized for the same time period as the CTRL and the IPC groups, but had no ischemic intervention. Microspheres were injected at baseline and at 15 and 60 min into the final reperfusion. All rats were euthanized and tissue harvested for spinal cord blood flow analysis. In Experiment 1, there was a slight, significant difference in spinal cord blood flow during the ischemic period; however, this difference soon disappeared during reperfusion. In experiment 2, there was no difference in blood flow at any experimental time. The results of these experiments demonstrate that IPC slightly enhances blood flow to the spinal cord during ischemia; however, this effect is not sustained during the reperfusion period.

Continuous distraction-induced delayed spinal cord injury on motor-evoked potentials and histological changes of spinal cord in a porcine model

“…In addition, persistent spinal column distraction may worsen or increase changes in the cord, which can lead to irreversible damage. 16,17,22,23,30 In regard to the MEP signal recovery patterns and wake-up test results, three pigs with smaller distraction lengths showed complete recovery, whereas five pigs with larger distraction lengths showed incomplete or no recovery in a similar distraction time. Therefore, this indicates that a distraction 470% of SVH may induce irreversible injury, which correlates with an MEP recovery signal deficit and a wake-up test after release.…”

“…Many animal models have been used to study traumatic SCI; however, these models differ with respect to iatrogenic SCI during surgery, and they also differ from human surgeries. [14][15][16][17][18][19][20][21][22][23] We hypothesized that it would be most instructive for surgeons to examine the effects of SCI in a large animal, induced by durational parallel spinal distraction over significant time intervals. The purpose of this study was to examine distraction-induced late-onset SCI (delayed SCI) with Tc-MEP and evaluate a wake-up test and corresponding histology consequences in a large animal model.…”

Amelioration of spinal cord compressive injury by pharmacological preconditioning with erythropoietin and a nonerythropoietic erythropoietin derivative

“…For example, ischemic preconditioning can provide significant neuroprotection after both focal and global cerebral ischemia 44,48 and can improve ischemic tolerance in the spinal cord as well. 1,66,67 Assuming that both traumatic and ischemic central nervous system injuries share several common mechanisms, it is expected that ischemic preconditioning will improve outcome after central nervous system traumatic injuries as well. In fact, ischemic preconditioning has been shown to increase the volume of preserved tissue after traumatic brain injury.…”

Limb ischemic preconditioning ameliorates renal microcirculation through activation of PI3K/Akt/eNOS signaling pathway after acute kidney injury

“…Studies using 3T functional magnetic resonance imaging (fMRI) suggested that on humans, LIPC alone could induce a higher oxygen content in kidney tissue [28], as well as increasing intra-renal perfusion [29]. Studies using laser Doppler flowmetry reported improved microcirculation on other organs, such as liver in Ischemia/Reperfusion (IR) model [30,31], and spinal cord blood flow [32]. In the present study, we first reported the amelioration of impaired renal medulla blood flow of LIPC in CI-AKI, and alleviated hypoxia condition of renal tissue after 15 and 30 min of CM administration, suggesting the important role of microcirculation in LIPC against CI-AKI.…”