Abstract
To quantitate the developmental changes in copper zinc and manganese superoxide dismutases (CuZnSOD and MnSOD) during the perinatal period, tissue sections were obtained from fetal (day 12 to day 22) and neonatal (day 6) rats, and were stained immunohistochemically using specific polyclonal antisera. The intensity of the staining was quantitated by fluorescence microscopy image analysis. There was a general trend of enriched SOD in the epithelial linings and metabolically active sites. Significant fluorescence was detected in hepatocytes, renal tubular epithelium, bronchial epithelium and intestinal epithelium at fetal day 15. The intensity increased in a stepwise manner thereafter. The fluorescent image for CuZnSOD was 1.6-fold more intense at postnatal day 6 than at fetal day 15 in each tissue studied. Similarly, the overall increase in the intensity of MnSOD staining was 2.0-fold in the liver, kidneys, and lungs, and 1.8-fold in the intestine. The phase of rapid increase for both SOD started at day 19 in most tissues. These results suggest that the intracellular O2--scavenging system develops during the perinatal period preferentially in epithelial tissues as an essential mechanism for living under atmospheric oxygen conditions.
