HeLa cells express cAMP-inhibitable sodium-dependent phosphate uptake. Am J Physiol 1990 Feb;258(2 Pt 2):F433-7
Date
02/01/1990Pubmed ID
2155543DOI
10.1152/ajprenal.1990.258.2.F433Scopus ID
2-s2.0-0025332311 (requires institutional sign-in at Scopus site) 7 CitationsAbstract
Receptor-mediated regulation of the sodium-phosphate symporter, and hence sodium-dependent phosphate uptake, typically relates to epithelial cells of renal origin. In this study we have characterized sodium-dependent phosphate uptake and aspects of its receptor-mediated regulation in the HeLa cell line, a cell line derived from a human epithelioid carcinoma. Phosphate uptake (greater than 90% sodium dependent; Vmax = 4.02 +/- 0.24 nmol.mg and Km = 0.11 +/- 0.02 mM phosphate at 140 mM sodium) was kinetically similar to that observed in opossum kidney cells. Incubation with vasoactive intestinal peptide (VIP) resulted in a dose-dependent (50% maximal dose of 8.8 +/- 3.6 nM) approximately fivefold increase in basal adenosine 3',5'-cyclic monophosphate (cAMP) levels (basal = 14.6 +/- 1.7 pmol.mg protein-1.15 min-1; VIP stimulated = 72.7 +/- 13.2 pmol.mg protein-1.15 min-1), as well as a dose-dependent maximal 32.6 +/- 5.5% decrease in sodium-dependent phosphate uptake (50% maximal decrease of 46.2 +/- 21.2 nM). The VIP-induced decrease in phosphate uptake was due to decrease in maximal transport (VmaxVIP = 2.78 +/- 0.16 nmol.mg protein-1.3 min-1) and not to a change in the affinity of the transporter for phosphate (KmVIP = 0.11 +/- 0.01 mM phosphate). Preincubation of HeLa cells with forskolin and cholera toxin, which stimulate adenylate cyclase, resulted in dose-dependent decreases in sodium-dependent phosphate uptake. Incubation with 8-bromo-cAMP and dibutyryl cAMP, permeant analogues of cAMP, similarly resulted in a dose-dependent decrease in sodium-dependent phosphate uptake.(ABSTRACT TRUNCATED AT 250 WORDS)
Author List
Raymond JR, Middleton JP, Dennis VWAuthor
John R. Raymond MD President, CEO, Professor in the President department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
8-Bromo Cyclic Adenosine MonophosphateBucladesine
Cholera Toxin
Colforsin
Cyclic AMP
HeLa Cells
Humans
Kinetics
Phosphates
Sodium
Time Factors
Vasoactive Intestinal Peptide