EFFECT OF PARATHYROID-HORMONE AND INTERLEUKIN-1-ALPHA IN OSTEOBLASTICMC3T3-E1 CELLS - INTERACTION WITH BETA-ALANYL-L-HISTIDINATO ZINC

beta-Alanyl-L-histidinato zinc(AHZ), which is an activator of bone for mation, has an inhibitory effect of bone resorption. Whether AHZ can i nhibit the effect of parathyroid hormone (PTH) or interleukin-1 alpha (IL-1 alpha), which is a bone resorbing factor, on osteoblastic MC3T3- E1 cells was investigated. After subculture for 3 days, the cells were cultured for 48 h with peptides. Parathyroid hormone(10(-9)-10(-7) M) or IL-1 alpha. (50 U/ml) caused a significant decrease in the cellula r alkaline phosphatase activity and a remarkable increase of prostagla ndin E(2) (PGE(2)) production in the cells. Parathyroid hormone (10(-7 ) M) or IL-1 alpha (50 U/ml) did not have an appreciable effect on the protein content of the cells. beta-Alanyl-L-histidinato zinc (10(-5) M) significantly increased the cellular alkaline phosphatase activity and protein content, whereas it had no effect on PGE(2) production. Th is increasing effect of AHZ was also seen in the presence of PTH (10(- 7) M) or IL-1 alpha (50 U/ml), although the effect of PTH and IL-1 alp ha to stimulate PGE(2) production was not modulated by AHZ treatment. The present finding suggests that the inhibitory effect of AHZ on bone resorption is not through osteoblasts.