167 MEASUREMENT OF 1,25 DIHYDROXYVITAMIN D. RECEPTORS (VDR) IN TERM BABIES CORD PERIPHERAL MONONUCLEAR CELLS (PMN)

Abstract

Genomic actions of vitamin D are mediated by VDR. Because the placental and fetal production of 1,25D, receptors should play its binding role, but little is known about their concentration in the newborn. In the rat peripheral mononuclear cell receptors for 1,25D (p VDR) reflect changes of VDR in target tissues (M.M. Ped Res 32:629, 1992).

We studied (m±SD) 13 healthy mothers well nourished (pre-pregnant p/T² 23.7±3.2); aged 24.9±3.7 y and with normal bone mineral content (0.859±0.1 g/cm) at delivery which took place in Dec/January. Newborn babies, were all healthy term and appropriate for gestational age. Once cord was clamped the artery was isolated, and blood was drawn for analysis of vitamin D polar metabolites and pVDR. VDR concentration was measured after 72 hours culture of PHA activated cells, by Scatchard analysis after 3H 1,25D binding. Results. 32 normal adults give values of pVDR in venous blood of 71.3±21.7 fmol/mg p. Cord blood showed normal figures for calcium, magnesium, phosphate and alk p-ase. Levels of 25D were 9.5±3.7 ng/mL; 1,25D 89.8±26.5 pg/mL and pVDR 87.9±20.2 fmol/mg p. The Kd values were of 4.7-7.1 E-10 M. A weak correlation (r = 0.38) was found between pVDR and 1,25D. In conclusion in term babies pVDR are binding adequately 1,25D and its concent, rat ion are moderately higher than in normal adults control. CAICYT PM 89-0018

Log in or create a free account to read this content

Gain free access to this article, as well as selected content from this journal and more on nature.com

Access through your institution

or

Sign in or create an account

Continue with Google

Continue with ORCiD