1186 calciotropic hormone responses in neonatal hypomagnesemia

ABSTRACT Calciotropic hormone responses in neonatal hypomagnesemia have not been reported. A 3 wk old term female infant developed hypomagnesemia (serum Mg 1.2-1.5 mg/dl) and hypocalcemia

(lowest serum calcium 4.1 mg%) over 2 wks. Serum parathyroid hormone (PTH) was 29μl-Eq/ml (normal ≤57μl-Eq/ml) and inappropriately low for the severe degree of hypocalcemia. PTH response to

Mg infusion was evaluated by infusing 6 mg/kg of Mg as 50% Mg So4 IV over 1 hr. Serum PTH rose gradually from 54 μlEq/ml to 63, 63, 61 and 129μl Eq/ml at 1/2, 1, 2, and 6 hrs. Urinary cyclic

AMP excretion rose from 1.75-5.0 nmole/mg creatinine before Mg to 7.8, 11.6, 3.4, 6.3, 8.5 n mole/mg creatinine over the next 6 hrs. Incremental doses of synthetic bovine PTH (1-34

fragment) resulted in responses in serum Ca at 6 hrs; ΔCa (change in Ca relative to controls) at 15 units/kg of PTH was 0.9 mg/dl, at 20 units/Kg 0.7 mg/dl, at 30 units/kg 1.5 mg/dl and at

35 units/kg 1.1 mg/dl. Serum calcitonin concentration was <10pg/ml (normal <107pg/ml). Rapid infusion of 5 mg/kg of Ca as 10% Ca gluconate resulted in a prompt calcitonin response from

<10 pg/ml to 77, 26 and 48 pg/ml at +1,+3 and + 5 min. Thus in neonatal hypomagnesemia, magnesium infusion resulted in increased circulating PTH; end organ responses to PTH appeared to

be intact; and calcium infusion elicited a prompt calcitonin response. We speculate that part of the etiology of hypocalcemia in neonatal hypomagnesemia is related to inapproriately low PTH

levels which can be corrected with magnesium. ARTICLE PDF AUTHOR INFORMATION AUTHORS AND AFFILIATIONS * U. of Cincinnati, P S Venkataraman, R C Tsang, F R Greer & V A Neumann Authors * P

S Venkataraman View author publications You can also search for this author inPubMed Google Scholar * R C Tsang View author publications You can also search for this author inPubMed Google

Scholar * F R Greer View author publications You can also search for this author inPubMed Google Scholar * V A Neumann View author publications You can also search for this author inPubMed 

Google Scholar RIGHTS AND PERMISSIONS Reprints and permissions ABOUT THIS ARTICLE CITE THIS ARTICLE Venkataraman, P., Tsang, R., Greer, F. _et al._ 1186 CALCIOTROPIC HORMONE RESPONSES IN

NEONATAL HYPOMAGNESEMIA. _Pediatr Res_ 15 (Suppl 4), 640 (1981). https://doi.org/10.1203/00006450-198104001-01212 Download citation * Issue Date: 01 April 1981 * DOI:

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