Extracellular calcium is essential for life and its concentration in the blood is maintained within a narrow range. This is achieved by a feedback loop that receives input from the calcium-sensing receptor (CASR), expressed on the surface of parathyroid cells. In response to low ionized calcium, the parathyroids increase secretion of parathyroid hormone (PTH) which increases serum calcium. The ...

The solubility of triclinic calcium pyrophosphate dihydrate (CPPD) crystals was measured under varying conditions using 45Ca-labeled crystals, expressing solubility as micromoles per liter of 45Ca in solution. In a 0.1-M Tris-HC1 buffer pH 7.4, the solubility of accurately sized CPPD crystals (37-20mum) was 60muM with maximal solubility being attained after about 8 h incubation at 37degreeC. Re...

IN man and most mammals the concentration of calcium in the blood and body fluids remains almost constant under normal conditions, with only slight fluctuations. For the various cellular functions which are dependent on calcium, for example neuromuscular transmission, it is the ionized fraction of calcium (approximately 50 per cent of the total serum calcium level) which is important, and it is...

INTRODUCTION Calcium has anti-proliferative and pro-differentiation effects on cells in vitro and can inhibit the development of various cancers. While there is some epidemiologic evidence for an inverse relation between dietary calcium intake and prostate cancer risk, only few have focused on serum calcium levels in this respect. MATERIALS AND METHODS We assayed total serum calcium and ioniz...

The objective of this study was to evaluate the hypothesis that a high concentration of ionized calcium in the lumen of the medullary collecting duct causes an osmole-free water diuresis. The urine flow rate and osmolality were measured in normal human subjects, as well as in patients with a history of nephrolithiasis who excreted more than 5 mmol of calcium per 24 h. There was an inverse relat...

The effects of various forms of acidosis on ionized calcium concentrations were investigated in vivo in rabbits and in vitro in human plasma. Calculation of least square regression equations of ionized calcium (mM) on pH yielded the following regression coefficients in human plasma: bypercapnic acidosis —0.53±0.07; hydrochloric acidosis —0.65 ±0.06; lactic acidosis —0.27±0.05. These findings in...

The parathyroid gland secretes parathyroid hormone (PTH) which is a key element in the regulation of serum calcium. The PTH elevates serum calcium activities by regulating its action on the bones, kidneys and small intestine. The set point of PTH secretion defines the sensitivity of the parathyroid glands to calcium concentration. Secondary hyperparathyroidism (SHPT) is a common complication of...

Abstract Background Low-ionized magnesium and high-ionized calcium levels are associated with increased cardiovascular mortality in patients undergoing dialysis. We examined the effects of dilution method, substitution volume, dialysate on-line hemodiafiltration on total ionized levels. Methods Eighteen were randomly assigned to three groups: two acetic acid groups one citrate group. Five treat...

Background: Pregnancy induced hypertension may complicate to preeclampsia and eclampsia. The pathophysiology of the former is still confusing, many authors suggested different opinions, and indicated different parameters for the prognosis of this. Aim: To evaluate serum HDL and LDL cholesterol, alkaline phosphatase, ionized calcium in pregnancy induced hypertension patients. Materials and metho...