Chloramphenicol inhibits not only the bacterial protein synthesis by binding to the 70S ribosome but also the mammalian mitochondrial protein synthesis. Since chloramphenicol has strong binding affinity to the bone marrow cells, bone marrow suppression is resulted from the administration of the chloramphenicol. In case the chloramphenicol is administered to pregnant rat, the fetal hematopoiesis as well as the adult hematopoiesis may be altered. So the auther undertook the present study to pursue the effect of the chloramphenicol on the number and morphological changes of the hematopoietic cells in the fetal liver.
Female Sprague-Dawley rats weighing 150g were mated with male rats and the pregnancy was confirmed by means of the vaginal smear. Chloramphenicol (300mg/kg) was administered to the experimental animals once a day from the 15th to the 20th day of the pregnancy. The specimens obtained from the liver of the fetus were fixed in the Zenker solution and stained with Hematoxylin-eosin-Azure II for light microscopic study.
The results were as follows.
1. In the 17, 18, and 19day old fetal livers treated with chloramphenicol, the number of proerythroblasts, basophilic erythroblasts, and normoblasts were similar to those of the control groups.
2. In the 19, and 20day old fetal livers treated with chloramphenicol, the number of the proerythroblasts and basophilic erythroblasts were increased slightly and cytoplasmic vacuoles were observed in the proerythroblasts in the 19day old fetal liver.
3. In the 19, 20, and 21day old fetal livers treated with chloramphenicol, the number of the normoblasts was decreased.
From the result of present study it is suggested that the parenterally administered chloramphenicol is transfered to the fetus in the form of chloramphenicol or its metabolites and it inhibits the fetal hematopoietic function.
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