Effect of parathyroid hormone and interleukin-1α in osteoblastic MC3T3-E1 cells: Interaction with β-alanyl- l-histidinato zinc

Abstract

β-Alanyl- l-histidinato zinc (AHZ), which is an activator of bone formation, has an inhibitory effect of bone resorption. Whether AHZ can inhibit the effect of parathyroid hormone (PTH) or interleukin-1α (IL-1α), 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-1α (50 U/ml) caused a significant decrease in the cellular alkaline phosphatase activity and a remarkable increase of prostaglandin E 2 (PGE 2) production in the cells. Parathyroid hormone (10 −7 M) or IL-1α (50 U/ml) did not have an appreciable effect on the protein content of the cells. β-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. This increasing effect of AHZ was also seen in the presence of PTH (10 −7 M) or IL-1α (50 U/ml), although the effect of PTH and IL-1α 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.