Volume 65, Issue 3, Pages 897-903 (March 2004) Regulation of PTH1 receptor expression by uremic ultrafiltrate in UMR 106–01 osteoblast-like cells  Sinee Disthabanchong, Hatim Hassan, Charles L. McConkey, Kevin J. Martin, Esther A. Gonzalez  Kidney International  Volume 65, Issue 3, Pages 897-903 (March 2004) DOI: 10.1111/j.1523-1755.2004.00472.x Copyright © 2004 International Society of Nephrology Terms and Conditions

Figure 1 Effect of uremic ultrafiltrate (UUF) on basal and parathyroid hormone (PTH)-stimulated cyclic adenosine monophosphate (cAMP) generation. Confluent cultures of UMR 106–01 cells were incubated in the presence (□) or absence (▪) of UUF for 48hours prior to acute stimulation with PTH (10-8 mol/L). PTH-stimulated cAMP generation was measured by radioimmunoassay (RIA). The values represent the mean ± SEM from 12 different samples. Kidney International 2004 65, 897-903DOI: (10.1111/j.1523-1755.2004.00472.x) Copyright © 2004 International Society of Nephrology Terms and Conditions

Figure 2 Time course of the effect of uremic ultrafiltrate (UUF) on parathyroid hormone (PTH)-stimulated cyclic adenosine monophosphate (cAMP) generation. Confluent cultures of UMR 106–01 cells were exposed to UUF for the times indicated prior to acute stimulation with PTH (10-8 mol/L). PTH-stimulated cAMP generation was measured by radioimmunoassay (RIA). The values represent the mean ± SEM from four different samples. *P < 0.01 as compared to time 0. Kidney International 2004 65, 897-903DOI: (10.1111/j.1523-1755.2004.00472.x) Copyright © 2004 International Society of Nephrology Terms and Conditions

Figure 3 Effect of chronic exposure to parathyroid hormone (PTH) concentrations present in uremic ultrafiltrate UUF on PTH-stimulated cyclic adenosine monophosphate (cAMP) generation. Confluent cultures of UMR 106–01 cells were exposed to PTH 10-12, 10-11, and 10-10 mol/L for 48hours prior to acute stimulation with PTH (10-8 mol/L). The values represent the mean ± SEM from four different experiments. Kidney International 2004 65, 897-903DOI: (10.1111/j.1523-1755.2004.00472.x) Copyright © 2004 International Society of Nephrology Terms and Conditions

Figure 4 Competitive inhibition of equilibrium binding of 125I Nle8,21Tyr34-rat PTH [1-34]NH2. Confluent cultures of UMR 106–01 cells were incubated in the presence (○) or absence (•) of uremic ultrafiltrate (UUF) for 48hours. Binding of 125I Nle8,21Tyr34-rat PTH [1-34]NH2 was examined in the presence of increasing concentrations of unlabeled parathyroid hormone (PTH). The inset shows a Scatchard analysis of the data. Kidney International 2004 65, 897-903DOI: (10.1111/j.1523-1755.2004.00472.x) Copyright © 2004 International Society of Nephrology Terms and Conditions

Figure 5 Effect of uremic ultrafiltrate (UUF) on parathyroid hormone receptor (PTH1R) mRNA levels. Confluent cultures of UMR 106–01 cells were exposed to UUF for the times indicated. Total RNA was isolated and PTH1R mRNA levels were determined by Northern analysis. The membranes were stripped and reprobed using a cDNA for glyceraldehyde-3-phosphate dehydrogenase (GAPDH) (A). Densitometric analysis of the levels of PTH1R mRNA corrected for GAPDH mRNA (B). The values represent the mean ± SEM from five different samples. *P < 0.01. Kidney International 2004 65, 897-903DOI: (10.1111/j.1523-1755.2004.00472.x) Copyright © 2004 International Society of Nephrology Terms and Conditions