The effect of hypermagnesaemia on serum immunoreactive calcitonin levels in normal human subjects

Abstract

The effect of hypermagnesaemia on serum levels of immunoreactive calcitonin was studied in normal human subjects. After iv administration of magnesium sulphate over 120 min, the mean (\m=+-\sem) serum magnesium concentration rose from the baseline level of 0.9 \m=+-\0.1 to 2.6 \m=+-\0.3 mmol/l (P < 0.01), and thereafter remained higher than the baseline level. The magnesium infusion caused a significant increase in serum immunoreactive calcitonin levels (P < 0.01). The rise in serum magnesium concentration was accompanied by a significant decrease in the concentrations of corrected serum calcium and whole blood ionized calcium (P < 0.01, P < 0.01, respectively). Our results suggest that hypermagnesaemia causes an increase in serum immunoreactive calcitonin levels in normal human subjects despite a decrease in the concentrations of corrected serum calcium and whole blood ionized calcium.Although calcium is the principal regulator of the thyroid C-cell function, magnesium has also been observed to have an important role. All reports of in vitro and in vivo animal studies indicate that magnesium, like calcium, stimulates the release of calcitonin (CT) from the thyroid gland (Radde et al. 1969; Bell 1970; Care et al. 1971; Littledike & Arnaud 1971). However, the effect of hypermagnesaemia on serum CT has not been extensively studied in normal human subjects. Some investi¬ gators demonstrated no significant change of se¬ rum immunoreactive CT (iCT) levels during mag¬ nesium infusion in pre-eclamptic women (Cruikshank et al. 1979), whereas others found a marked increased level of serum iCT during magnesium administration (Deftos et al. 1978). On the other hand, Anast et al. (1975) reported that magne¬ sium administration caused a decrease in circula¬ ting iCT in patients with thyroid medullary car¬ cinoma. To study the effect of hypermagnesaemia on serum iCT levels in normal human subjects, we analysed changes in serum iCT levels, and con¬ centrations of corrected serum calcium and whole blood ionized calcium during and after iv admini¬ stration of magnesium sulphate. Subjects and MethodsSeven healthy men ranging in age from 20 to 34 years (mean 26 years) participated in the study. Informed consent was obtained from each subject. Our investiga¬ tion was conducted in accordance with the principles of the Declaration of Helsinki II and was approved by our institutional review board. While the subjects were

Effects of Intravenous Magnesium Sulfate on Calcium-Regulating Hormones, Plasma and Urinary Electrolytes in Healthy Horses

“…It is made The copyright holder for this preprint this version posted February 10, 2021. ; https://doi.org/10.1101/2021.02.10.430592 doi: bioRxiv preprint gland C cells in response to hypercalcemia to restore normocalcemia by blocking osteoclastmediated bone resorption and reducing renal calcium reabsorption. There is evidence in other species that hypermagnesemia also stimulates CT secretion [11,12].…”

Effects of intravenous magnesium sulfate on serum calcium-regulating hormones and plasma and urinary electrolytes in healthy horses

“…Calcitonin (CT) is secreted by the thyroid gland C cells in response to hypercalcemia to restore normocalcemia by blocking osteoclast-mediated bone resorption and reducing renal calcium reabsorption. There is evidence in other species that hypermagnesemia also stimulates CT secretion [11,12].…”