Phosphate Depletion in Opossum Kidney Cells: Apical But Not Basolateral or Transepithelial Adaptions of Pi Transport

2001 ◽  
Vol 9 (4) ◽  
pp. 258-264 ◽  
Author(s):  
M. Barac-Nieto ◽  
M. Alfred ◽  
A. Spitzer
Keyword(s):  
Kidney Cells ◽  
Opossum Kidney ◽  
Pi Transport ◽  
Opossum Kidney Cells ◽  
Phosphate Depletion

Resistance to parathyroid hormone-induced inhibition of inorganic phosphate transport in opossum kidney cells cultured in low inorganic phosphate medium

1992 ◽  
Vol 134 (3) ◽  
pp. 361-368 ◽  
Author(s):  
J. Caverzasio ◽  
J.-P. Bonjour
Keyword(s):  
Inorganic Phosphate ◽  
Kidney Cells ◽  
Camp Production ◽  
Cellular Resistance ◽  
Opossum Kidney ◽  
Pi Transport ◽  
Camp Generation ◽  
Opossum Kidney Cells ◽  
Cells Cultured ◽  
In Cells

ABSTRACT Renal resistance to the phosphaturic action of parathyroid hormone (PTH) is observed during dietary deprivation of inorganic phosphate (Pi) in vivo. In the present work, the influence of short (3 h)- or long (72 h)-term deprivation of Pi on the effect of bovine PTH (bPTH(1–34)) on both Na-dependent Pi transport and cyclic AMP(cAMP) production was examined in cultured opossum kidney epithelium. Na-dependent Pi transport increased by 100% in cells exposed to low Pi medium containing no Pi (LPM) for 3 h, as compared with transport in high Pi medium containing 2 mmolPi/l (HPM). In response to a submaximal dose (1 nmol/l) of bPTH(1–34), Na-dependent Pi transport was similarly inhibited by about 40% in LPM and HPM. This inhibition was preceded by increased cAMP production which was identical in LPM and HPM. In opossum kidney cells exposed for 72 h to LPM, Na-dependent Pi transport was also increased by 100% compared with that in HPM. However, bPTH(1–34) added at 1 nmol/l did not induce any significant change in Na-dependent Pi transport or cAMP. Stimulation of cAMP could only be elicited at bPTH(1–34) concentrations higher than 1 nmol/l. Such a reduced cAMP response was also observed with forskolin in cells incubated for 72 h in LPM. The cellular resistance to the generation of cAMP was associated with a significantly lower level of ATP in cells cultured for 72 h in LPM compared with ATP levels in HPM. There was a good relationship between cellular ATP level and expression of the inhibitory effect of bPTH on Pi transport in culture media containing various concentrations of Pi. In conclusion, long-term Pi depletion in opossum kidney cells leads to cellular resistance to PTH-induced cAMP generation and inhibition of Pi transport. The lower level of cAMP in Pi-depleted cells is probably due to insufficient substrate for cAMP generation. It is likely that other ATP-dependent processes involved in cellular Pi transport regulation might also be affected in the severely Pi-depleted cells and contribute to the resistance of PTH action on Pi transport inhibition. Journal of Endocrinology (1992) 134, 361–368

Evidence for interference of vitamin D with PTH/PTHrP receptor expression in opossum kidney cells

1998 ◽  
Vol 436 (2) ◽  
pp. 289-294 ◽  
Author(s):  
H. Wald ◽  
Michal Dranitzki-Elhalel ◽  
R. Backenroth ◽  
Mordecai M. Popovtzer
Keyword(s):  
Vitamin D ◽  
Receptor Expression ◽  
Kidney Cells ◽  
Opossum Kidney ◽  
Opossum Kidney Cells ◽  
Pthrp Receptor
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