Activation of phosphoinositide metabolism by parathyroid hormone in growth plate chondrocytes

• Published in: Cell calcium (Edinburgh) Vol. 16; no. 2; pp. 112 - 122
• Main Authors: Zuscik, M.J., Gunter, T.E., Rosier, R.N., Gunter, K.K., Puzas, J.E.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier India Pvt Ltd 01.08.1994; Elsevier
• Subjects: Animals; Biological and medical sciences; Cell Division - drug effects; Cell Membrane - chemistry; Cell Membrane - metabolism; Cell Membrane - ultrastructure; Cell physiology; Cells, Cultured; Chickens; Fundamental and applied biological sciences. Psychology; Growth Plate - chemistry; Growth Plate - cytology; Growth Plate - metabolism; Hormonal regulation; Inositol 1,4,5-Trisphosphate - analysis; Inositol 1,4,5-Trisphosphate - metabolism; Molecular and cellular biology; Parathyroid Hormone - pharmacology; Phosphatidylinositols - analysis; Phosphatidylinositols - metabolism; Phosphoinositide; Calcium; Chondrocyte; Parathyroid hormone; Hormonal regulation; Cyclic AMP; Metabolism
• ISSN: 0143-4160; 1532-1991
• DOI: 10.1016/0143-4160(94)90006-X

Parathyroid hormone (PTH) is one of the most potent stimulators of growth plate chondrocyte mitogenesis that has been reported. However, study of the second messenger signaling mechanisms involved in the transduction of the hormone's effects on these cells is incomplete. Our data indicate that in addition to stimulating cyclic adenosine-3′5′-monophosphate metabolism, PTH also activates the phosphoinositide cascade, the pathway responsible for the generation of inositol-1,4,5-trisphosphate dependent Ca 2+ signals. Our conclusion that PTH activates the phosphoinositide cascade is based on data that demonstrate: (1) the Ca 2+ transients evoked by the hormone are dependent on intracellular Ca 2+ stores; (2) the hormone stimulates the release of radiolabeled inositol phosphates from GPC plasma membranes; and (3) the hormone stimulates a greater than 8-fold increase in cytosolic inositol-1,4,5-trisphosphate pool size.