Enhancement of the stimulatory effect of calcium on aldosterone secretion by parathyroid hormone.
In previous clinical investigations on uremic patients we found a stimulatory effect of the presence of hyperparathyroidism on the Ca(2+)-induced secretion of various hormones, i.e. aldosterone and vasopressin. The present investigation, therefore, examined the possible effect of PTH on the calcium-mediated aldosterone secretion from isolated, purified zona glomerulosa cells obtained from the rat. After washing the cells and after 30 min of preincubation Ca2+ was added to the preparations at concentrations from 0.5 to 2.0 mmol and PTH(1-84) or PTH(1-34) were added at concentrations from 10(-7) to 10(-10) M. The cells were then incubated for 120 min and aldosterone measured in the supernatant. The aldosterone response to Ca2+ stimulation--without PTH added--served as baseline controls, while cell preparations with ACTH 10(-6) M added secured the viability and responsiveness of the cells. In all cell preparations with PTH(1-84) as well as PTH(1-34) added the aldosterone responses to a certain Ca2+ concentration increased significantly by up to 200% (p < 0.001) above baseline values. It is suggested that PTH may have a Ca2+ ionophore-like effect on endocrine glands, which are not normally related to PTH and thus enhance the calcium-stimulated hormone secretion. The hypothesis is raised that this phenomenon may take place in uremia during the state of secondary hyperparathyroidism.
Olgaard
K
K
Medical Department P, Rigshospitalet, Copenhagen, Denmark.
Lewin
E
E
Bro
S
S
Daugaard
H
H
Egfjord
M
M
Pless
V
V
D000324:Adrenocorticotropic Hormone / Q000494:pharmacology; D000450:Aldosterone / Q000378:metabolism*; D000818:Animals; D000001:Calcimycin / Q000494:pharmacology; D002118:Calcium / Q000494:pharmacology*; D002469:Cell Separation; D005260:Female; D010281:Parathyroid Hormone / Q000494:pharmacology / Q000502:physiology*; D010446:Peptide Fragments / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D019379:Teriparatide; D015384:Zona Glomerulosa / Q000187:drug effects / Q000378:metabolism*
D010281:Parathyroid Hormone; D010446:Peptide Fragments; D019379:Teriparatide; D000001:Calcimycin; D000450:Aldosterone; D000324:Adrenocorticotropic Hormone; D002118:Calcium