Chronic kidney disease (CKD) is associated with increased concentration of intracellular calcium, which is pathological and may lead to irreversible damage of cell functions and structures. The aim of our study was to investigate the impact of 6 months vitamin D3 supplementation (14 000 IU/week) on free cytosolic calcium concentration ([Ca2+]i) and on the plasma membrane calcium ATPase (PMCA) activity of patients with CKD stage 2-3. PMCA activity of patients was also compared to that of healthy volunteers. Vitamin D3 supplementation of CKD patients resulted in the decrease of [Ca2+]i (119.79±5.87 nmol/l vs. 105.36± 3.59 nmol/l, n=14, P<0.001), whereas PMCA activity of CKD patients (38.75±22.89 nmol Pi/mg/h) remained unchanged after vitamin D3 supplementation (40.96±17.74 nmol Pi/mg/h, n=14). PMCA activity of early stage CKD patients before supplementation of vitamin D3, was reduced by 34 % (42.01±20.64 nmol Pi/mg/h) in comparison to healthy volunteers (63.68±20.32 nmol Pi/mg/h, n=28, P<0.001). These results indicate that vitamin D3 supplementation had a lowering effect on [Ca2+]i and negligible effect on PMCA activity in CKD patients., M. Morvová Jr., I. Lajdová, V. Spustová, M. Zvarík, L. Šikurová., and Obsahuje bibliografii
Vitamin D3 is well-known as a major regulator of calcium and
phosphorus homeostasis. A growing body of evidence highlights
its crucial role in the regulation of reproductive processes in
females. The role of vitamin D3 in the female reproductive tract
has been extensively investigated because its receptor is
abundant in reproductive organs, including ovary. Importantly,
besides expression of vitamin D3 receptor, the ovary is an
extrarenal site of vitamin D3 metabolism. The influence of vitamin
D3 on follicular development and ovarian steroidogenesis has
been investigated. Furthermore, vitamin D3 deficiency has also
been associated with polycystic ovary syndrome, premature
ovarian failure and ovarian cancer. The objective of this review is
to summarize our knowledge about the contribution of vitamin D3
to physiological and pathological processes within the ovary.