Vitamin D substrate–product relationship in idiopathic hypercalciuria

Bevilacqua, Maurizio; Lj, Dominguez; Gandolini, Giorgio; Valdes, Valeria; Vago, Tarcisio; Righini, Velella; Barrella, Massimo; Barbagallo, Mario

doi:10.1016/j.jsbmb.2008.08.010

Cited by 5 publications

(11 citation statements)

References 41 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…1a-Hydroxylase has been cloned (33)(34)(35), and studies of the molecular mechanisms involved in its regulation demonstrated that administration of PTH and calcitonin, restriction of dietary calcium, and vitamin D deficiency are able to increase 1a-hydroxylase mRNA expression. On the other hand, administration of 1,25(OH) 2 D results in a decrease in 1a-hydroxylase expression and prevents the increased expression induced by PTH and calcitonin (36). In our study, the increased 1a-hydroxylase activity in PH patients could be related to elevated PTH serum levels, as described previously (24).…”

Section: Resultssupporting

confidence: 80%

“…Therefore, hypercalcemia concomitant with normal serum PTH levels may suppress 1a-hydroxylase, regardless of the presence or absence of CASR mutations. Moreover, according to previous works in animal models (41,42) 2 D. Finally, it cannot be excluded that the low levels of hCT found in FBH may play a role in the impairment of 1a-hydroxylase (27).…”

Section: Discussionmentioning

confidence: 94%

“…The substrate-product relationship between 25(OH)D and 1,25(OH) 2 D has been postulated and investigated in previous studies (1,2,4). Some authors have reported the lack of a significant substrate-product relationship in experimental models (7).…”

Section: Discussionmentioning

confidence: 99%

“…The vitamin D metabolism is the result of a complex multifactorial control mechanism, and some evidence of a substrate-product relationship between 25(OH)D and 1,25(OH) 2 In healthy subjects, the administration of 25(OH)D at a low dose (25 mg) produces an increase in 25(OH)D serum levels within the normal range (below 120 ng/ml) and an increase in 1,25(OH) 2 D (2,8). Similarly, exogenous administration of 25(OH)D in patients affected by primary hyperparathyroidism (PH) is followed by an increase in serum levels of 1,25(OH) 2 D, suggesting a substrate-product relationship in these subjects (9).…”

Section: Introductionmentioning

confidence: 99%

“…Similarly, exogenous administration of 25(OH)D in patients affected by primary hyperparathyroidism (PH) is followed by an increase in serum levels of 1,25(OH) 2 D, suggesting a substrate-product relationship in these subjects (9). By contrast, monitoring of 1,25(OH) 2 D serum levels after administration of 25(OH)D in patients affected by familial benign hypocalciuric hypercalcemia (FBH) has never been performed.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Different vitamin D substrate–product relationship after oral vitamin D supplementation in familial benign hypercalcemia, primary hyperparathyroidism, and healthy controls

Bevilacqua

Invernizzi

Righini³

et al. 2011

European Journal of Endocrinology

Self Cite

View full text Add to dashboard Cite

Context: In healthy subjects and in patients with primary hyperparathyroidism (PH), the administration of a low dose of 25(OH)D (25 mg/day) increases the serum levels of both 25(OH)D and 1,25(OH) 2 D. It is unknown whether this relationship is present in patients affected by familial benign hypocalciuric hypercalcemia (FBH). Objective: To evaluate the different vitamin D substrate-product relationship after oral vitamin D supplementation in familial benign hypercalcemia, PH, and healthy controls. Design: We evaluated the main physiological regulators of 1a-hydroxylase and the substrate-product relationship of 25(OH)D and 1,25(OH) 2 D in 20 patients with PH, 25 with FBH, and 122 healthy sex-and age-matched controls before and after administration of 25(OH)D for 2 weeks. Results: 25(OH)D increased significantly in all subjects, whereas 1,25(OH) 2 D serum levels increased significantly in PH patients and healthy controls but not in patients with FBH. Therefore, a significant positive substrate-product relationship of 25(OH)D-1,25(OH) 2 D was found in PH and healthy controls, but not in FBH. Monomeric calcitonin (hCT-M) was significantly lower at baseline and after 25(OH)D supplementation in the FBH group compared with the other two groups. Conclusions: The lack of 1,25(OH) 2 D increase in FBH may be due to a direct inhibitory effect on 1a-hydroxylase of hypercalcemia per se, increased metabolic clearance of 1,25(OH) 2 D, or a decreased stimulus of 1a-hydroxylase related to persistently low levels of hCT.

show abstract

Section: Resultssupporting

confidence: 80%

Section: Discussionmentioning

confidence: 94%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Different vitamin D substrate–product relationship after oral vitamin D supplementation in familial benign hypercalcemia, primary hyperparathyroidism, and healthy controls

Bevilacqua

Invernizzi

Righini³

et al. 2011

European Journal of Endocrinology

Self Cite

View full text Add to dashboard Cite

show abstract

Current World Literature

2010

Current Opinion in Urology

View full text Add to dashboard Cite

Immunomodulatory Effects of 1,25-Dihydroxyvitamin D3 on TH1/TH2 Cytokines in Inflammatory Bowel Disease: An in Vitro Study

Ardizzone¹,

Cassinotti²,

Trabattoni

et al. 2009

Int J Immunopathol Pharmacol

View full text Add to dashboard Cite

Crohn's disease (CD) is associated with a higher type-1-helper T cell (Th1) cytokine expression, whereas ulcerative colitis (UC) appears to express a modified Th2 response. In addition to its classic role in calcium homeostasis, calcitriol, the hormonal active form of vitamin D, exerts immunoregulatory effects such as modulation of Th1/Th2 cytokines. Therefore, calcitriol administration could modify immune dysfunction in CD and UC. Nine patients with UC (M/F: 5/4; mean age 47 years, remission(R)/active(A) disease: 7/2), 8 patients with CD (M/F: 2/6; mean age 36, R/A 5/3) and 6 healthy controls (HC) (M/F: 3/3, mean age 4) were enrolled. Peripheral blood was collected after a drug-washout of 15 days and peripheral blood mononuclear cells were stimulated with mitogens alone or in the presence of physiological concentrations of calcitriol (100 pg/ml). Type 1 (IL-2, TNF-alpha, IFN-gamma) and type 2 (IL-10) cytokine production was assayed on supernatants by ELISA. Compared to HC, TNF-alpha production was significantly higher both in UC (p=0.0002) and CD (p=0.0001) patients, at baseline and after incubation with calcitriol (UC p=0.0003, CD p=0.0009). The effects of calcitriol incubation were: 1) reduced IFN-gamma (p=0.024) and increased IL-10 (p=0.06) production in UC patients; 2) reduced TNF-alpha production in CD (p=0.032); 3) no significant effects in HC. Calcitriol increased, albeit not significantly, IL-10 production in UC compared to CD patients (p=0.09). These results suggest an important modulatory role of vitamin D in the Th1/Th2 immune response. The observation that the effect of this modulation was different in CD compared to UC patients provides an interesting area of research into the pathogenesis and treatment of these inflammatory conditions.

show abstract

Vitamin D substrate–product relationship in idiopathic hypercalciuria

Cited by 5 publications

References 41 publications

Different vitamin D substrate–product relationship after oral vitamin D supplementation in familial benign hypercalcemia, primary hyperparathyroidism, and healthy controls

Different vitamin D substrate–product relationship after oral vitamin D supplementation in familial benign hypercalcemia, primary hyperparathyroidism, and healthy controls

Current World Literature

Immunomodulatory Effects of 1,25-Dihydroxyvitamin D3 on TH1/TH2 Cytokines in Inflammatory Bowel Disease: An in Vitro Study

Contact Info

Product

Resources

About