Investigation of the effect of experimentally induced acute anemia and acute inflammation on the cardiac muscle in rabbits

Many studies suggested that cardiac muscle damage occured in some infectious and inflammatory diseases concomitant with anemia. It has been demonstrated that inflammation alone caused cardiac muscle damage, but there is no evidence that anemia alone would be able to cardiac muscle damage up to now. We aimed to determine whether anemia could cause cardiac muscle damage in rabbits with experimentally induced acute normovolemic anemia. Twenty eight New Zealand rabbits was used. Rabbits were randomly divided into four groups as Acute Inflammation (AI) Group (n=8), Acute Inflammation Control (AIK) Group (n=6), Acute Anemia (AA) Group (n=8) and Acute Anemia Control (AAK) Group (n=6). To create acute anemia, repeated phlebotomy was perfromed until hematocrit value fall around %10-15 for 4-5 days at 24 hours intervals. Blood samples taken from AA and AAK groups at 0, 24th, 48th, 72nd, 96th and 120th hours. To create acute inflammation, cecal ligation and punction model was performed in rabbits in AI group. Blood samples were taken from AI and AIK groups at 0, 4th, 8th and 12th hours of the experiment. After end of experiment, all rabbits was euthanized and heart tissue was taken for histopathological and immunohistochemical analysis. Serum concentration of cardiac troponin I (cTnI) was significantly higher (P<0,01) in AA group (0.072±0.045 ng/mL) than AAC group (0.015±0.005 ng/mL). Also, serum concentration of cTnI was significantly higher (P<0,01) in AI group (1,177±0,971) than AIC group (0.031±0.021). Histopathologically, coagulated necrosis areas, mononuclear cell infiltration, loss of muscle stration, picnotic nuclei, dark eosonophilic staining and loss of cell boundries was detected. It was also found that cytoplasmic cTnI immunoreactivity was decreased in AA and AI groups compared to control groups. The results of this experimental study suggest that acute anemia causes cardiac muscle damage and there is significant negative correlation between anemia and serum cTnI levels. Key words: Rabbit, anemia, endotoxemia, cardiac troponin I, pathology.