Histopathology of Heart and Spleen as a Result of Chromium Exposure in Mice

Potassium dichromate (K2CR2O7) contains hexavalent chromium that was tested for cardiac and splenic histopathology and micro anatomical and morphometric analysis at sub-toxic chronic exposure in drinking water in mice at 50 ppm, 100 ppm and 200 ppm concentration. Its duration of exposure was 30 days. The forty animals were divided into 4 groups as Group I was designated as Control (Ctl) received free normal drinking water, other groups (Group II-IV) were Cr (VI)50 ppm, Cr(VI)100 ppm, Cr(VI)200 ppm received 50, 100 and 200 ppm chromium in drinking water respectively. The animals were sacrificed after 30 days of exposure to obtain the heart and spleen for histological preparation. The digital photographs obtained from selected slides were analyzed histo-anatomically. Considerable decrease in red pulp of spleen was observed in Cr(VI)50 ppm (8.07±0.76), Cr(VI)100 ppm (7.74±0.30) and Cr(VI)200 ppm (7.35±0.65) in a dose dependent manner as compared to Ctl (8.24±0.86). Relative cell abundance in red pulp of Cr(VI)50 ppm (0.81±0.13), Cr(VI)100 ppm (0.65±0.16) and Cr(VI)200 ppm (0.6±0.1) was decreasing as compared to Ctl group (1.47±0.20). However, interestingly white pulp of spleen was increased in Cr (VI)50 ppm (1.31±0.15), Cr(VI)100 ppm (1.47±0.10) and Cr(VI)200 ppm (1.72±0.15) in dose dependent manner as compared to Ctl (1.55±0.15). While heart tissue indicate variation in the mean cross sectional area (CSA) of the cardiac fibers along with damaged to end plates, merger of the adjacent fibers necrosis followed by fibrosis in the myocardial myometrium. The results shows clear impression that persistent low concentration (50 ppm)chromium exposure in drinking water can be dangerous to myometrium leading to congestive heart problems, cardiac failure, brady cardia along with many hematological implications.