title: Parathyroid hormone secretion and serum calcium concentration--a deterministic view of its regulation.
abstract: In seven normal men we investigated the basal secretion of PTH by blood sampling in 30 sec intervals for estimation of intact PTH and at 2-min intervals for measurement of ionized calcium. In 4 of these subjects we also investigated the PTH-secretion under conditions of intermittent hypercalcemia and hypocalcemia. Our measurements demonstrate the existence of three time scales in the secretion of PTH, viz. short-term pulses (faster than 2 min), an intermediate pattern of adjusting PTH levels to changed Ca2+ averages, and finally a long-term coupling between PTH and Ca2+ averages after 20 min. Ionized calcium controls the long-term regulation and intermediate adaptation mechanisms, but the short-term fluctuations seem to be due to spontaneous secretion.
authors.affiliation: Nephrologische Abteilung Medizinische Universitätsklinik, Würzburg, Germany.
authors.forename: E
authors.initials: E
authors.lastname: Heidbreder
authors.forename: H
authors.initials: H
authors.lastname: Naujoks
authors.forename: U
authors.initials: U
authors.lastname: Brosa
authors.forename: L
authors.initials: L
authors.lastname: Schramm
authors.forename: R
authors.initials: R
authors.lastname: Götz
mesh_terms: D000328:Adult; D002118:Calcium / Q000097:blood*; D006801:Humans; D008297:Male; D010281:Parathyroid Hormone / Q000097:blood / Q000378:metabolism*
chemical_list: D010281:Parathyroid Hormone; D002118:Calcium