Daunomycin isolated from culture broth of Streptomyces peucetius in 1963 is a member of the anthracyclin class of antitumor antibiotics. Chemically it is -found to consist of a pigmented aglycone (daunomycinone) bound to an aminosugar, daunosamine. The biochemical mode of cytotoxic action of daunomycin results from its binding to DNA possibley by intercalation between the base pairs inhibiting the DNA polymerase activity and dissociating the DNA double helical strands.
The author has investigated the effect of daunomycin on the mouse duodenum histochemically observing the change in the activity of alkaline phosphatase. The animals treated with 15mg per kg of daunomycin were sacrificed at 12, 24 and 48 hours after the drug administration and fasted for 12 hours before sacrificing animals of the control and experimental groups. The animals of the control group were ad-ministered only water for injection.
The duodenum specimens were fixed in 10%-neutral formalin at 4C and sectioned 1611 thickness in frozen cryostat. The activity of alkaline phosphatase was evaluated histochemically by Gomori´s method and incubation time of sliced specimen was 20 minutes.
The results were as follows.
1. The activities of alkaline phosphatase were moderately positive in the epithelium of duodenum of the control group, weakly positive in the 12 hours daunomycin treated group, moderate positive in the 24 hours daunomycin treated group and weakly positive in the 48 hours daunomycin treated group. With the lapse of time, irregular shaped and atrophied villi were observed. The weakly positive activity of alkaline phosphatase in the lamina propria and trace positive activity in the submucosa and muscle layer were observed in the control and all daunomycin treated group. There were no significant differences in the lamina propria, submucosa and muscle layer between the control and daunomycin treated groups.
Consequently, it is suggested that daunomycin reduces the activity of alkaline
phosphatase in the epithelium of the duodenum of mouse.
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