We describe a novel model of myocardial infarction (MI) in rats induced by percutaneous transthoracic low-energy laser-targeted photodynamic irradiation. elevated at 6 h (41 6 ng/ml, = 4, < 0.05 vs. baseline) and returned to baseline after 72 h. Triphenyltetrazolium chloride staining revealed transmural anterolateral infarcts targeting 25 3% of the left ventricle at with a decrease to 20 3% at (= 6 for each group, < 0.01 vs. = 51 rats was associated with 12% total mortality. Histological findings, ECG abnormalities, and elevated cTnI levels confirmed the photosensitizer-dependent induction of MI after laser irradiation. This novel rodent model of MI might provide a platform to evaluate new diagnostic or therapeutic interventions. is the percent area of infarction from planimetry of a particular section is the weight of the corresponding section. Histopathological analysis. Heart tissue samples were fixed in 4% (vol/vol) neutral-buffered formaldehyde, embedded in paraffin, cut into 5-m-thick sections, and stained with hematoxylin-eosin. The photomicrographs were taken using a Olympus BH-2 microscope equipped with a Nikon digital camera DXM1200 (Nikon, Tokyo, Japan) and are representative of the experimental groups. Computed tomography imaging. Computed tomography (CT) scans were acquired using the X-SPECT imaging system. CT scans were acquired using following settings: 70 kV at 350 A and a 1 1 binning mode of the X-ray detector with 512 projections collected on a 360 rotation. Tomographic reconstruction has been done using a standard filtered back projection, and three-dimensional CT data sets were processed and analyzed on the AMIRA System (TGS, San Diego, CA). Determination of cardiac troponin levels. Blood samples were collected via tail vein before and at designated time points after the photodynamically induced MI. The heparinized plasma was analyzed for concentration of rat cardiac troponin I (cTnI), which was determined in heparinized plasma using sandwich ELISA (Kamiya Biomedical, Ginsenoside Rh1 IC50 Seattle, WA) according to the manufacturer's protocol, and results are expressed as mass of circulating protein related to the plasma volume. Statistical analyses. All results are expressed as means with corresponding standard deviation. Gaussian distribution of measured values was confirmed using Kolmogorov-Smirnov tests. To compare the infarct sizes at different time points, analysis of variance (ANOVA) was applied with consequent Dunett's test using the 1-day post-MI data as reference group. For cTnI values, ANOVA for repeated measurements was applied followed by the Bonferroni's post hoc test to evaluate the differences between respective groups, and < 0.05 was considered significant. All statistical analyses were performed using the Prism program (GraphPad Software, La Jolla, CA). RESULTS X-ray-guided targeted laser illumination of photosensitized heart tissue induces MI. To triangulate the area to be irradiated and align laser fiber optics over the area of the LV, we performed X-ray scans of the anesthetized animals. The thoracic area was marked with X-ray contrast agent to form a matrix of reference points. The radiopaque fiducial markers were visible on X-ray scans and could be easily distinguished from high-density structures, such as thoracic bones, as well as other tissues. This array of fiducial marks facilitated triangulation and allowed positioning of Ginsenoside Rh1 IC50 the laser beam (Fig. 1, and (shown … Histopathological analyses reveal tissue destruction and replacement fibrosis after photodynamically induced transmural infarcts. Myocardial injury was further assessed at different time points after the photodynamic procedure Ginsenoside Rh1 IC50 by histological evaluation. Histology of heart tissue from control animals (i.e., irradiated without administration of photosensitizer) showed preserved cardiac structure and well-distinguished cardiomyocytes with intact transversal striations (Fig. 2, and and and and and and after irradiation, photodynamic irradiation of animals injected with photosensitizer reproducibly induced moderate anterolateral infarcts targeting 25 3% of the LV (Fig. 3< 0.01 vs. = 6, Fig. 3to after laser illumination demonstrate ... Anterolateral infarction was associated with significant elevation of circulating cTnI after photodynamically induced MI. The plasma levels of cTnI, a marker of myocardial injury, were determined Rabbit Polyclonal to GPRC5C by ELISA at different time points after photodynamic infarction. Animals that received photosensitizer showed marked elevation of cTnI, 40.5 5.8 ng/ml at 6 h after irradiation, significantly above baseline of the plasma collected before photodynamic irradiation (Fig. 3C). Consequently, cTnI levels in the.

We describe a novel model of myocardial infarction (MI) in rats

Leave a Reply

Your email address will not be published. Required fields are marked *