Plasma concentrations of calcium, phosphate, citrate, albumin, and parathyroid hormone (PTH) were measured during and after exchange transfusion of infants suffering from haemolytic disease using blood anticoagulated with acid-citrate and dextrose (ACD) or heparin. Pretransfusion plasma PTH and phosphate both correlated positively with postnatal age but not with each other. Transfusion with ACD...

In three patients with thyrotoxicosis and with symptomatic hypercalcaemia antithyroid therapy restored the plasma calcium concentration to normal, though initially in one case intravenous and oral neutral phosphate solution were required to curtail intractable vomiting.Nine cases have been recorded in which the plasma calcium concentration returned to normal after antithyroid treatment was star...

Bovine epididymal spermatozoa incubated aerobically in vitro in the presence of 0.1 to 0.2 mM CaCl2 accumulate 25 to 50 nmol of calcium/10(8) cells. The addition of low concentrations of the ionophore A23187 (0.01 to 0.5 nmol/mg of sperm protein) induces efflux of this accumulated calcium. At high ionophore concentrations (0.5 to 5.0 nmol/mg of sperm protein), calcium release is followed by an ...

It has been suggested that glucagon-like immunoreactivity (GLI) of gastrointestinal tissues might, like pancreatic glucagon, have calcium-lowering activity. Studies were designed, therefore, to determine if calcium absorption was associated with GLI release from the gut. The intraduodenal administration of 4.5 mmoles of calcium chloride per kg of body weight to conscious dogs was associated wit...

Recently it has been demonstrated that there are differences between sheep and goats in respect to adaptation to a calcium-restricted diet. It was the aim of the present study to evaluate whether species-specific peculiarities also occur when calcium homoeostasis is challenged by lactation. Therefore, we investigated the time courses of plasma parameters related to calcium homoeostasis (calcium...

Ionic, hormonal, and blood pressure responses to a single oral dose of the calcium channel blocker nifedipine were assessed in 25 essential hypertensive subjects. When grouped according to their renin-sodium profile, low renin subjects had a greater hypotensive response to nifedipine (change in diastolic blood pressure -20.0 +/- 1.4 vs -6.4 +/- 1.0%; p less than 0.005) than did high renin hyper...

Calcium formate is a water-soluble salt of an essential mineral nutrient with potential for use as a dietary calcium supplement. Formate ion is a product of endogenous and xenobiotic metabolism, but sustained high plasma formate concentrations (such as occur in cases of methanol poisoning) are toxic to the retina and optic nerve. Humans and primates have reduced capacity for formate oxidation c...

A complex bio-mechanism, referred to as calcium homeostasis, regulates plasma ionized calcium (Ca++) concentration in the human body to within a narrow physiologic range which is crucial for maintaining normal physiology and metabolism. Various metabolic disorders and pathologic conditions origi∗Address all correspondence to this author. nate from acute and/or chronic disturbances/disorders in ...

Calcium (Ca) preparations are widely used in the treatment of osteoporosis, usually as soluble salts. Tolerance might be improved by prescription of slowly dissolved Ca preparations, since Ca is also absorbed distally, even in the colon. In this regard the use of natural forms of Ca might be advantageous, but natural products cannot be labeled reliably for easy evaluation of their absorption. T...

Although it is well established that parathyroid hormone and phosphate are important regulators of 1,25-dihydroxyvitamin D [1,25(OH)2D] production, it remains unclear whether calcitonin affects vitamin D metabolism in vivo. Experiments were performed in the rat to determine the effect of chronic calcitonin infusion (0.2 U X h-1) on plasma levels of vitamin D metabolites and on calcium metabolis...