A novel model of acute murine hindlimb ischemia

Crawford, Robert S.; Hashmi, Faraz; Jones, John E.; Albadawi, Hassan; McCormack, Michael C.; Eberlin, Kyle R.; Entabi, Fateh; Atkins, Marvin D.; Conrad, Mark F.; Austen, William G.; Watkins, Michael T.

doi:10.1152/ajpheart.00581.2006

Cited by 71 publications

(69 citation statements)

References 31 publications

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“…15,23,38 The explicit aim of the model design was to amend translational research. Earlier rodent models have used tourniquets 28 or rubber bands 39 and lacked vascular access for selective reperfusion. Venous stasis as a consequence of these approaches, however, is not a part of clinical limb ischemia and has been associated with severe damage to the microcirculation in earlier studies.…”

Section: Discussionmentioning

confidence: 99%

Basic Control of Reperfusion Effectively Protects Against Reperfusion Injury in a Realistic Rodent Model of Acute Limb Ischemia

et al. 2008

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Background-Reperfusion injury is insufficiently addressed in current clinical management of acute limb ischemia.Controlled reperfusion carries an enormous clinical potential and was tested in a new reality-driven rodent model. Methods and Results-Acute hind-limb ischemia was induced in Wistar rats and maintained for 4 hours. Unlike previous tourniquets models, femoral vessels were surgically prepared to facilitate controlled reperfusion and to prevent venous stasis. Rats were randomized into an experimental group (nϭ7), in which limbs were selectively perfused with a cooled isotone heparin solution at a limited flow rate before blood flow was restored, and a conventional group (nϭ7; uncontrolled blood reperfusion). Rats were killed 4 hours after blood reperfusion. Nonischemic limbs served as controls. Ischemia/reperfusion injury was significant in both groups; total wet-to-dry ratio was 159Ϯ44% of normal (Pϭ0.016), whereas muscle viability and contraction force were reduced to 65Ϯ13% (Pϭ0.016) and 45Ϯ34% (Pϭ0.045), respectively. Controlled reperfusion, however, attenuated reperfusion injury significantly. Tissue edema was less pronounced (132Ϯ16% versus 185Ϯ42%; Pϭ0.011) and muscle viability (74Ϯ11% versus 57Ϯ9%; Pϭ0.004) and contraction force (68Ϯ40% versus 26Ϯ7%; Pϭ0.045) were better preserved than after uncontrolled reperfusion. Moreover, subsequent blood circulation as assessed by laser Doppler recovered completely after controlled reperfusion but stayed durably impaired after uncontrolled reperfusion (Pϭ0.027). Conclusions-Reperfusion

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Section: Discussionmentioning

confidence: 99%

Basic Control of Reperfusion Effectively Protects Against Reperfusion Injury in a Realistic Rodent Model of Acute Limb Ischemia

et al. 2008

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“…Bilateral hind-limb I/R was performed as reported (38). Briefly, WT and IAP KO mice, aged 6 -8 weeks, were anesthetized by i.p.…”

Section: Iap Enzyme Activity and Lps-dephosphorylating Assaymentioning

confidence: 99%

Intestinal alkaline phosphatase is a gut mucosal defense factor maintained by enteral nutrition

Goldberg

Austen

Zhang

et al. 2008

Proc. Natl. Acad. Sci. U.S.A.

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318

323

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Under conditions of starvation and disease, the gut barrier becomes impaired, and trophic feeding to prevent gut mucosal atrophy has become a standard treatment of critically ill patients. However, the mechanisms responsible for the beneficial effects of enteral nutrition have remained a mystery. Using in vitro and in vivo models, we demonstrate that the brush-border enzyme, intestinal alkaline phosphatase (IAP), has the ability to detoxify lipopolysaccharide and prevent bacterial invasion across the gut mucosal barrier. IAP expression and function are lost with starvation and maintained by enteral feeding. It is likely that the IAP silencing that occurs during starvation is a key component of the gut mucosal barrier dysfunction seen in critically ill patients.A mong the most critical functions of the mammalian gut mucosa is to provide a barrier to luminal microbes and toxins while simultaneously allowing for the necessary digestion and absorption of dietary nutrients. The molecular mechanisms that govern barrier function are incompletely understood, but it is clear that under conditions of starvation and disease, the gut barrier becomes impaired, leading to significant morbidity and mortality (1-8). Trophic enteral feeding to prevent gut mucosal atrophy and resultant barrier dysfunction has become part of the standard treatment of intensive care unit patients (9-14). The mechanism(s) responsible for the beneficial effects of trophic feeding are not understood.Intestinal alkaline phosphatase (IAP), a brush-border protein that hydrolyzes monophosphate esters, is expressed exclusively in villus-associated enterocytes and is considered an excellent marker for crypt-villus differentiation (15-18). Narisawa et al. (19) reported that compared with their wild-type (WT) littermates, mice lacking IAP gained more weight under conditions of a high-fat diet. In addition, several studies have shown that the IAP enzyme is capable of detoxifying LPS, likely through dephosphorylation of the lipid A moiety, the primary source of its endotoxic effects (20). Despite these few reports, the physiological role of IAP within the gut has not been elucidated. Results and DiscussionTo examine the functional role of IAP, we developed in vitro model systems using intestinal cell lines (T84, HT-29, and IEC-6) that express little or no IAP under basal conditions. Stable cell lines were created that overexpress IAP (Fig. 1A), and enzyme assays were used to determine the cellular localization of the ectopically expressed IAP protein. The results in Fig. 1B show that parent cells make little, if any, endogenous IAP. In contrast, large amounts of IAP enzyme are seen in the stably transfected cells. Importantly, the vast majority of the IAP activity is in the membrane fraction as opposed to the cytosol. Fig. 1C shows the results of the control experiment used to validate our separation of membranous and cytosolic fractions, confirming that the majority of the MAPK enzyme activity exists within the cytosol rather than the membrane. This membrane ...

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“…The skeletal muscle I/R injury model was constructed according to previous studies [14, 15]. In general, unilateral hindlimb ischemia was induced by placing an orthodontic rubber band at the right hip joint using a McGivney hemorrhoidal ligator for 3 hours followed by removal of the orthodontic rubber band tourniquet for 1, 3, 5, 7 or 14 days of reperfusion.…”

Section: Methodsmentioning

confidence: 99%

“…In general, unilateral hindlimb ischemia was induced by placing an orthodontic rubber band at the right hip joint using a McGivney hemorrhoidal ligator for 3 hours followed by removal of the orthodontic rubber band tourniquet for 1, 3, 5, 7 or 14 days of reperfusion. During the pre-ischemic, ischemic, and initial 3 hours of reperfusion intervals, mice were placed on a heating pad to maintain body temperature at 37°C [14]. Tourniquet-induced I/R injury was identified by measuring blood flow to the gastrocnemius muscle as described previously [15, 16].…”

Section: Methodsmentioning

confidence: 99%

Protective Effects of Sonic Hedgehog Against Ischemia/Reperfusion Injury in Mouse Skeletal Muscle via AKT/mTOR/p70S6K Signaling

Zeng¹,

Fu²,

Wang³

et al. 2017

Cell Physiol Biochem

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Background/Aims: Skeletal muscle ischemia/reperfusion (I/R) injury is a common and severe disease. Sonic hedgehog (Shh) plays a critical role in post-natal skeletal muscle regeneration. In the present study, the role of Shh in skeletal muscle I/R injury and the mechanisms involved were investigated. Methods: The expression of Shh, AKT/mTOR/p70S6K and apoptosis pathway components were evaluated following tourniquet-induced skeletal muscle I/R injury. Then, mice were subjected to systemic administration of cyclopamine or one-shot treatment of a plasmid encoding the human Shh gene (phShh) to examine the effects of Shh on I/R injury. Moreover, mice were subjected to systemic administration of NVP-BEZ235 to investigate the role of the AKT/mTOR/p70S6K pathway in Shh-triggered skeletal muscle protection. Results: We found that the levels of Shh, AKT/mTOR/p70S6K pathway components and Cleaved Caspase 3 and the Bax/Bcl2 ratio initially increased and then decreased at different time points post-I/R injury. Moreover, Shh protected skeletal muscle against I/R injury by alleviating muscle destruction, reducing interstitial fibrosis and inhibiting apoptosis, and these protective effects were abrogated when the AKT/mTOR/p70S6K pathway was inhibited. Conclusion: Collectively, these data suggest that Shh signaling exerts a protective role through the AKT/mTOR/p70S6K signaling pathway during skeletal muscle I/R injury. Thus, Shh signaling may be a therapeutic target for protecting skeletal muscle from I/R injury.

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A novel model of acute murine hindlimb ischemia

Cited by 71 publications

References 31 publications

Basic Control of Reperfusion Effectively Protects Against Reperfusion Injury in a Realistic Rodent Model of Acute Limb Ischemia

Basic Control of Reperfusion Effectively Protects Against Reperfusion Injury in a Realistic Rodent Model of Acute Limb Ischemia

Intestinal alkaline phosphatase is a gut mucosal defense factor maintained by enteral nutrition

Protective Effects of Sonic Hedgehog Against Ischemia/Reperfusion Injury in Mouse Skeletal Muscle via AKT/mTOR/p70S6K Signaling

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