1. Development and progression of secondary hyperparathyroidism in chronic kidney disease: lessons from molecular genetics 
William G. Goodman, L.D. Quarles 
Kidney International 
Volume 74, Issue 3, Pages (August 2008)
DOI: /sj.ki
Copyright © 2008 International Society of Nephrology Terms and Conditions

2. Figure 1
The respective roles of calcium ions, acting through the CaSR, and vitamin D sterols, acting through the VDR, as direct modifiers of parathyroid gland function.
Kidney International  , DOI: ( /sj.ki )
Copyright © 2008 International Society of Nephrology Terms and Conditions

3. Figure 2
The distribution of calcium among various tissue compartments. A miscible, or rapidly exchangeable, pool of calcium in bone participates in the regulation of plasma calcium homeostasis and serves to maintain a constant level of ionized calcium in blood.
Kidney International  , DOI: ( /sj.ki )
Copyright © 2008 International Society of Nephrology Terms and Conditions

4. Figure 3
Plasma PTH levels (triangles, dashed line, left y-axis) and blood-ionized calcium concentrations (right y-axis) at 1-min intervals in a volunteer with normal renal and parathyroid gland function. Note that plasma PTH levels fluctuate over time, consistent with pulsatile PTH release that is regulated by the CaSR. In contrast, blood-ionized calcium levels remain constant (Goodman, unpublished observations).
Kidney International  , DOI: ( /sj.ki )
Copyright © 2008 International Society of Nephrology Terms and Conditions

5. Figure 4
Plasma PTH levels rise abruptly (a) when blood-ionized calcium concentrations are lowered (b) during intravenous infusions of sodium citrate both in normal volunteers and in patients with bone biopsy-proven hyperparathyroidism due to CKD. Maximum levels are reached within 10–20min, but values do not increase thereafter despite a continued decrease in blood-ionized calcium (from Ramirez et al.43).
Kidney International  , DOI: ( /sj.ki )
Copyright © 2008 International Society of Nephrology Terms and Conditions

6. Figure 5
A graphic depiction of the vitamin D response element (VDRE) and the calcium-response element (CRE) located upstream from the gene for pre-pro-PTH. Both elements negatively regulate gene transcription.
Kidney International  , DOI: ( /sj.ki )
Copyright © 2008 International Society of Nephrology Terms and Conditions

7. Figure 6
The percentage changes in plasma PTH levels during intravenous infusions of calcium gluconate in volunteers with normal renal and parathyroid gland function, in patients with bone biopsy-proven hyperparathyroidism due to CKD, in patients with severe SHPT who were few days before undergoing surgical parathyroidectomy, and in patients with primary hyperparathyroidism due to parathyroid adenoma. The non-suppressible component of PTH release differs substantially from normal in each clinical disorder (from Goodman et al.42).
Kidney International  , DOI: ( /sj.ki )
Copyright © 2008 International Society of Nephrology Terms and Conditions