Rat and rabbit heart infarction: effects of anesthesia, perfusate, risk zone, and method of infarct sizing

Abstract

Rabbits and rats are becoming popular models for in vitro as well as in situ studies of myocardial infarction. In the present analysis we evaluated the results of several of our completed investigations and tested whether blood-free perfusate, anesthesia, or risk zone size affects infarction in these species. In addition, the influence of the method used for determining infarct size (histology or histochemistry) was examined in rabbits. All hearts experienced 30 min of regional ischemia followed by either 2-3 h of reperfusion in animals in which infarct size was assessed by staining with triphenyltetrazolium chloride or 72 h in those in which histological methods were used to measure infarct size. Eighteen rabbit and seven rat hearts perfused with Krebs buffer, seventeen open-chest rabbits, eight rats anesthetized with pentobarbital, and ten conscious rabbits were studied. Risk zone size measured with fluorescent particles was plotted against infarct size. Infarct size was linearly correlated with risk zone size and did not differ among models for each species. In rat hearts the regression line passed through the origin so that zero infarction occurred with zero risk zone size. However, in the rabbit heart there was no apparent infarction for risk zone sizes < 0.3 cm3. Although the relationship between risk zone and infarction was found to be remarkably independent of the model chosen, the nonzero intercept for the rabbit heart can be an important, previously unrecognized source of experimental variability when infarct size is expressed as a percentage of the risk zone.

VEGF165 and angiopoietin-1 decreased myocardium infarct size through phosphatidylinositol-3 kinase and Bcl-2 pathways

“…Blood was washed out from the heart by PBS through aorta. Infarct size measuring by the tetrazolium method was indicated by Ytrehus et al 24 IA, RA and LA were calculated from enlarged digital micrographs with UTHSCSA ImageTool according to different colors (Pale white ¼ infarct area, Red ¼ living at risk, Blue ¼ normal, Risk area ¼ pale white+red). The ratios (%, heart weight integrated) of IA to RA and RA to LA were calculated.…”

Multipotent adult progenitor cells sustain function of ischemic limbs in mice

“…For immunohistochemistry and immunofluorescence, a list of primary antibodies is provided as supplemental information (Supplemental Table 2). Whole muscle viability assays were performed on unfixed tissue slices of approximately 2 mm in thickness after staining with TTC, as described previously (48). Pictures for morphometric analysis were taken using a Retiga EXi camera (Q Imaging) connected to a Nikon E800 microscope or a Zeiss Axio Imager connected to an Axiocam MRc5 camera (Zeiss), and analysis was performed using ImageJ (http://rsb.…”

Identification of Noncytotoxic and IL-10–Producing CD8+AT2R+ T Cell Population in Response to Ischemic Heart Injury

“…Infarct size was evaluated as previously described (13). In brief, recipient rats were sacrificed 2 wk after MI and syngeneic intramyocardial cell transplantation.…”