In the present study the effect of L-azetidine-2-carboxylic acid on uptake of
3H-proline into incisor dentin of young rats is investigated.
For the experiment,
3H-proline (50mCi/g) and L-azetidine-2-carboxylic acid (1 mg/g) were simultaneously injected into rats. The first rat was killed 10 min, the second one 30 min, the third one 1 hr, the fourth one 6 hr, and the last one 24 hr after the injection. The upper and lower incisors were used for light and electron microscopic autoradiography. In the control, the same procedure was performed but with an injection of 50mCi/g of
3H-proline only.
Quantitative analysis of
3H-proline incorporation into dentin and pulp of the upper incisors was done and radioactivity was counted by a liquid scintillation-counter.
In the control group, at 10 and 30 min after the injection, grains were found in odontoblasts. At 1 and 6 hr after the injection, they were distributed in the predentin, and the grains were in the dentin 24 hr after the injection.
In the treated group, on the other hand, grains were found in odontoblasts at 30 min and 6 hr. Moreover, the grains in the treated group were distributed rather sparsely. The result of the quantitative analysis by a liquid scintillation-counter indicated that the amount of
3H-proline incorporated into dentin in the treated group was about one third of that in the control. No significant difference was found in the pulps between the treated and the control animals.
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