A new model for studying ischemia-reperfusion injury in hamster cheek pouch

Abstract

The cheek pouch was prepared as a single layer and attached to a two-piece Lucite chamber that was filled with bicarbonate buffer (pH 7.35, equilibrated with 95% N2-5% CO2). Two microcirculatory areas were circumscribed in the cheek pouch by equilateral triangular chambers. Each chamber was made of 90-microns thick Mylar sheet (2 mm wide, 18 mm long). A cover slip was used as the chamber top. Ischemia was induced by applying pressure to the cover slip. The experimental area was reperfused after 1 h of ischemia by releasing the pressure. The other area served as control. One hour of reperfusion after 1 h of ischemia caused a significant increase in the number of leukocytes adhering to postcapillary venules (PCVs) per 100 microns vessel length in the ischemic area relative to the values in the control area (7.8 +/- 2.5 vs. 3.7 +/- 1.3, respectively, for PCVs 10-19.9 microns diam; and 10.9 +/- 2.8 vs. 6.2 +/- 1.8 for PCVs 20-29.9 microns diam; P less than 0.01 for both comparisons). The results demonstrate the adequacy of the model to investigate leukocyte adhesion to endothelium in ischemia-reperfusion. Because blood flow is maintained in most of the pouch, our model should also be useful for identifying possible interactions between ischemic and nonischemic areas in the microcirculation.

The Experimental Use of Syrian Hamsters

“…Ischemia-reperfusion injury is caused by several factors including the generation of reactive oxygen and nitrogen species and the resulting lipid peroxidation; cytokine production following leukocyte margination, adherence, and infiltration; and activation of the complement system (de Groot and Rauen, 2007;de With et al, 2005;Kaminski et al, 2002; IV. HAMSTERS Yasuhara et al, 1991). The Syrian hamster is extensively used to reveal the pathophysiological mechanisms of ischemia-reperfusion injury, as well as therapeutic options to preserve tissue and vascular viability.…”

“…Numerous models of ischemia-reperfusion injury are described using the Syrian hamster cheek pouch. In the model of pressure-induced ischemia a translucent pressure chamber is pressed against the cheek pouch for variable amounts of time and then released to produce reperfusion (Romanus et al, 1977;Yasuhara et al, 1991). The disadvantage of this model is that the results are influenced by the pressure applied to the tissue.…”

“…The disadvantage of this model is that the results are influenced by the pressure applied to the tissue. In a second model, ischemia is produced by tightening a latex cuff around the neck of an everted cheek pouch for up to an hour followed by cuff release (Persson et al, 1985;Yasuhara et al, 1991). The disadvantage of this model is that tension on the retractor muscle is produced by the everted preparation.…”

Microcirculatory Exchange Function

“…For example, if the investigator's interest is cardiac ischemia-reperfusion (I/R) injury, either the hamster cheek pouch or cremaster muscle model would be more relevant than the mesentery model [86][87][88][89] . The choice of a particular model will depend on the objective of the study.…”

Leukocytes express connexin 43 after activation with lipopolysaccharide and appear to form gap junctions with endothelial cells after ischemia-reperfusion.

“…Also, cultured vascular endothelial cells (21), a mouse macrophage cell line (J774) (22), and the macrophage foam cells of atherosclerotic lesions (23) Ischemia-Reperfusion of the Cheek Pouch. Ischemiareperfusion was induced in the check pouch as described by Yasuhara et al (26). In brief, the hamster cheek pouch was prepared for intravital microscopy by inserting a Lucite plate and a fiber optic bundle through the mouth and placing a hollow Lucite chamber through an incision in the skin on the external surface of the pouch (27).…”