CYTOKINE PRODUCTION BY PERIPHERAL-BLOOD MONONUCLEAR-CELLS AND METABOLIC TURNOVER OF BONE DURING PREGNANCY

We studied the dynamic turnover of bone by measuring metabolic markers in 6 healthy pregnant women, aged 23-28. Resorption markers, tartrate -resistant acid phosphatase and deoxypyridinoline, increased in the la st trimester and after partrition decreased until puerperium day 30. T he serum level of intact osteocalcin, a formation marker, exhibited a slight decrease during pregnancy and increased following childbirth. I n the last trimester, the peripheral monocyte secreted much amount of interleukin (IL)-1 and tumor necrosis factor (TNF)-alpha, potent stimu lants of osteoclast, in parallel with the resorption markers. Estrogen has the bone sparing effect by inhibiting cytokine secretion in the b one microenvironment and peripheral mononuclear cell. Biomarker change s, however, disclosed uncoupling of bone with high resorption and low formation in the last trimester with a higher estrogen level than any other period of life, which might be mediated by a high amount of IL-1 and TNF-alpha through stimulating osteoclast activity.