AJP - Renal Physiology, Vol 259, Issue 3 485-F493, Copyright © 1990 by American Physiological Society

ARTICLES

Stimulation of transient elevations in cytosolic Ca2+ is related to inhibition of Pi transport in OK cells

A. Miyauchi, V. Dobre, M. Rickmeyer, J. Cole, L. Forte and K. A. Hruska
Department of Medicine, Jewish Hospital at Washington University, St. Louis 63110.

Stimulation of changes in cytosolic free calcium by parathyroid hormone was determined in three opossum kidney (OK) cell types, OK wild-type, OKP clone, and OKH clone. All three types of OK cells express parathyroid hormone (PTH)-sensitive adenylate cyclase and adenosine 3',5'-cyclic monophosphate (cAMP) production. However, only the OK wild-type and the OKP clone respond to PTH with inhibition of sodium-dependent Pi transport and transient increase in cytosolic calcium. Characterization of the increases in cytosolic calcium in the wild-type and OKP clones revealed they were due in part to stimulation of Ca2+ release from intracellular stores, probably by inositol 1,4,5-trisphosphate (IP3), which was stimulated by PTH. PTH-stimulated Ca2+ transients were also inhibited by protein kinase C activation. These data are compatible with PTH receptor-mediated phospholipase C activation and its feedback inhibition by protein kinase C. The OKH cells demonstrated a slow increase in cytosolic calcium when stimulated by cyclic nucleotides but no evidence for PTH stimulation of Ca2+ release from intracellular stores. Thus the absence of an inhibitory response of sodium-dependent Pi transport to PTH in the OKH cells is associated with the absence of the rapid transient elevations of cytosolic Ca2+ such as those produced by IP3 production. These data suggest an important cooperative role for cAMP and the phospholipase C-stimulated Ca2(+)-protein kinase C message system in the regulation of Pi transport.

This article has been cited by other articles:

				S. J. Khundmiri, M. Ameen, N. A. Delamere, and E. D. Lederer PTH-mediated regulation of Na+-K+-ATPase requires Src kinase-dependent ERK phosphorylation Am J Physiol Renal Physiol, August 1, 2008; 295(2): F426 - F437. [Abstract] [Full Text] [PDF]

				S. J. Khundmiri, A. Ahmad, R. E. Bennett, E. J. Weinman, D. Steplock, J. Cole, P. D. Baumann, J. Lewis, S. Singh, B. J. Clark, et al. Novel regulatory function for NHERF-1 in Npt2a transcription Am J Physiol Renal Physiol, April 1, 2008; 294(4): F840 - F849. [Abstract] [Full Text] [PDF]

				R. J. Dixon, K. Young, and N. J. Brunskill Lysophosphatidic acid-induced calcium mobilization and proliferation in kidney proximal tubular cells Am J Physiol Renal Physiol, February 1, 1999; 276(2): F191 - F198. [Abstract] [Full Text] [PDF]

				J. Nagai, I. Yano, Y. Hashimoto, M. Takano, and K.-I. Inui Inhibition of PAH transport by parathyroid hormone in OK cells: involvement of protein kinase C pathway Am J Physiol Renal Physiol, November 1, 1997; 273(5): F674 - F679. [Abstract] [Full Text] [PDF]