Adriamycin alters the alkaline phosphatase activity in hamster molars during development in vitro

The effect of a 2 hour exposure to adriamycin (1 mg/litre) on alkaline phosphatase (ALPase) activity of the golden hamster 4-5 day old second maxillary molars (M2) was investigated in vitro. The molars were grown in BGJb medium containing 15% fetal bovine serum, glutamine (200 micrograms/ml), vitamin C (250 micrograms/ml), penicillin G (50 micrograms/ml), and streptomycin sulphate (30 micrograms/ml). The gas phase contained 50% O2 + 5% CO2 + 45% N2. The molars were supported on cellulosic membrane filters and grown for 3, 5, and 7 days at the medium-gas interface in a closed humidified chamber. Biochemical analysis indicated a steady increase in ALPase activity throughout this study in the control samples. However, after adriamycin treatment no increase in ALPase activity could be observed. The histochemical data showed that the increased activity in the control was confined to the peripheral pulp, sub-odontoblastic layer, stratum intermedium, ameloblasts and odontoblasts. Although these layers showed a decreased activity after adriamycin treatment, the ameloblasts showed an increase in activity over the control. The data has shown that adriamycin caused a reduction in total ALPase activity in developing molars in vitro; osteodentin production by pulp cells; and appeared to produce an acceleration in the differentiation of ameloblasts.