Lack of effect of human parathyroid hormone and calcitonin on cytokine and prostaglandin secretion by blood mononuclear cells.

The interactions between the endocrine and immune systems are complex and not well understood. Several data suggest the existence of a particular relation between bone and immune cells. Cells of the immune system express specific receptors for various calciotropic hormones, including parathyroid hormone (PTH) and calcitonin. In addition, several drugs used in the therapy of osteoporosis have been reported to modify the release of bone-active substances by immune cells. These facts prompted us to study in vitro the possible influence of PTH and calcitonin on the secretion of interleukin-1 (IL-1), tumor necrosis factor (TNF) and prostaglandin E2 (PGE) by peripheral blood mononuclear cells (PBMC). These three mediators show potent bone-resorbing activity. However, we did not find any significant effect of pharmacological concentrations of PTH or calcitonin on the secretion of IL-1, TNF or PGE by PBMC.