title: Interleukin-6 induced suppression of bovine parathyroid hormone secretion.
abstract: Calcium disturbances in the critically ill coincide with elevations of proinflammatory cytokines. The effects of tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) on parathyroid hormone (PTH) secretion were investigated. IL-6 and TNF-alpha had no acute effect on PTH secretion in extracellular Ca2+ concentrations of 0.5, 1.25 and 3.0 mM. In contrast to TNF-alpha, cultures for 24 h in the presence of 10 ng/mL of IL-6 showed decreased PTH secretion by 51% and 29% in 0.5 mM and 1.25 mM Ca2+ respectively. Neither IL-6 nor TNF-alpha, affected cytoplasmic Ca2+ of the cells. We conclude that PTH secretion in vitro can be suppressed by IL-6 at clinically relevant concentrations. This suppression may aggravate hypocalcemia of the critically ill and attenuate the conventionally strong stimulation of the PTH release by reduction in serum calcium.
authors.affiliation: Department of Medicine, University Hospital of Uppsala, Sweden.
authors.forename: E
authors.initials: E
authors.lastname: Carlstedt
authors.forename: P
authors.initials: P
authors.lastname: Ridefelt
authors.forename: L
authors.initials: L
authors.lastname: Lind
authors.forename: J
authors.initials: J
authors.lastname: Rastad
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism / Q000494:pharmacology; D002417:Cattle; D002478:Cells, Cultured; D006801:Humans; D015850:Interleukin-6 / Q000378:metabolism* / Q000494:pharmacology; D010280:Parathyroid Glands / Q000166:cytology / Q000378:metabolism*; D010281:Parathyroid Hormone / Q000378:metabolism*; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism / Q000494:pharmacology
chemical_list: D015850:Interleukin-6; D010281:Parathyroid Hormone; D014409:Tumor Necrosis Factor-alpha; D002118:Calcium