Chloramphenicol, isolated from the Streptomyces venezuelae, has been used as an antibioties against wide range of bacteria including Haemophilus influenzae, Salmonella, Staphylococci, Streptococci and Pneumococci species. It is widely used
in the treatment of venereal disease, salmonellosis, enteritis, Hodgkin´s disease and typhoid.
Chloramphenicol inhibits not only the bacterial protein synthesis by binding to the 70S ribosome but also the mammalian mitochondria protein synthesis. In case the chloramphenicol is administered to pregnant rat, the fetal growth and differentiation of cells in perichondrium may be damaged. So the author undertook the present study to pursue the effect of the chloramphenicol on chondrogenic cells and prechondrocytes in the perichondrium of tibial cartilage models.
Female Sprague-Dawley rats weighing 200 gm were mated with the male rats and the pregnancy was confirmed by means of the vaginal smear. Chloramphenicol (300 mg/kg) was administered to the experimental animals once per day from the 8th to the 14th day of the pregnancy. The specimens obtained from the fetal tibia at the 15th, 18th and 21th day of the pregnancy were fixed in 10% formaline and paraffin sections of tibia cartilage models were stained with alcian blue (pH 2.5) for light microscopic observation and perichondrium of tibial cartilage models of each fetal stage during pregnancy was made double stained with uranyl acetate and lead citrate for observation by electron microscope.
The results obtained were as follows:
1. In the chloramphenicol treated fetal tibia, cartilage model showed irregular shapes and reduced mesenchymal cells and thinned perichondrium were observed.
2. In the chloramphenicol treated fetal tibia, cisternae of the rough endoplasmic reticulum in the chondrogenic cells and precartilage cells were dilated and sacculated. Mitochondriae were swollen and their cristae were dilated and Golgi complexes were atrophied.
3. In the chloramphenicol treated fetal tibia, collagen fibrils and secretory granules of the matrix were reduced.
Consequently, it is suggested that chloramphenicol shows toxic effects on the precartilage cells:. chondrogenic cells and perichondrium so that the synthesis of cartilage matrix be reduced.
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