TY - JOUR
T1 - Fibroblast growth factor 23 concentrations in healthy term infants during the early postpartum period
AU - Takaiwa, Masanori
AU - Aya, Kunihiko
AU - Miyai, Takayuki
AU - Hasegawa, Kosei
AU - Yokoyama, Motofumi
AU - Kondo, Yoichi
AU - Kodani, Nobuyuki
AU - Seino, Yoshiki
AU - Tanaka, Hiroyuki
AU - Morishima, Tsuneo
N1 - Funding Information:
This work was supported in part by grants JKFB08-49 , JKFB09-53 and JKFB10-10 from the Kidney Foundation, Japan . We deeply appreciate the dedication of Ms. Georgina Meredith Dip.T., B.Ed. for her scientific advice and technical support.
PY - 2010/8
Y1 - 2010/8
N2 - Fibroblast growth factor 23 (FGF23) is a potent regulator of Pi and 1,25-(OH)2D homeostasis. Early postpartum infants show intriguing changes in serum levels of Ca, Pi, PTH and 1,25-(OH)2D. However, the role of FGF23 in the early neonatal mineral metabolism has not been clarified. In order to evaluate the significance of FGF23 during the early postpartum period, we examined the circulating FGF23 levels using an intact FGF23 ELISA and a C-terminal FGF23 ELISA either in 22 umbilical cord blood samples (the cord blood) or in 22 term infants at 5days of life (the 5-day-old infant). We also compared these ranges with those of 11 healthy adults. Data were expressed as mean±SD, and analyzed by two-way ANOVA, followed by the Tukey's test. C-terminal FGF23 in the cord blood, the 5-day-old infants and the healthy adults were 73.3±22.4, 81.0±28.2 and 39.0±7.8 RU/ml, respectively. Intact FGF23 in the cord blood, the 5-day-old infants and the healthy adults were 3.9±1.6, 21.8±17.6, and 27.6±7.3 pg/ml, respectively. Immunoprecipitation assays using anti-FGF23 antibodies demonstrated that the intact 32 kDa FGF23 was low and the fragmented FGF23 of 18kDa was abundant in the cord blood compared with those in the healthy adults. In conclusion, our observations indicated that the intact FGF23/C-terminal FGF23 ratio was very low due to the fragmentation of FGF23 during the early postpartum period and might have a considerable contribution to the Pi homeostasis in the healthy term infants.
AB - Fibroblast growth factor 23 (FGF23) is a potent regulator of Pi and 1,25-(OH)2D homeostasis. Early postpartum infants show intriguing changes in serum levels of Ca, Pi, PTH and 1,25-(OH)2D. However, the role of FGF23 in the early neonatal mineral metabolism has not been clarified. In order to evaluate the significance of FGF23 during the early postpartum period, we examined the circulating FGF23 levels using an intact FGF23 ELISA and a C-terminal FGF23 ELISA either in 22 umbilical cord blood samples (the cord blood) or in 22 term infants at 5days of life (the 5-day-old infant). We also compared these ranges with those of 11 healthy adults. Data were expressed as mean±SD, and analyzed by two-way ANOVA, followed by the Tukey's test. C-terminal FGF23 in the cord blood, the 5-day-old infants and the healthy adults were 73.3±22.4, 81.0±28.2 and 39.0±7.8 RU/ml, respectively. Intact FGF23 in the cord blood, the 5-day-old infants and the healthy adults were 3.9±1.6, 21.8±17.6, and 27.6±7.3 pg/ml, respectively. Immunoprecipitation assays using anti-FGF23 antibodies demonstrated that the intact 32 kDa FGF23 was low and the fragmented FGF23 of 18kDa was abundant in the cord blood compared with those in the healthy adults. In conclusion, our observations indicated that the intact FGF23/C-terminal FGF23 ratio was very low due to the fragmentation of FGF23 during the early postpartum period and might have a considerable contribution to the Pi homeostasis in the healthy term infants.
KW - 1,25-dihydroxy vitamin D
KW - Calcium
KW - Fibroblast growth factor 23
KW - Intact PTH
KW - Phosphate
KW - Term infants
UR - http://www.scopus.com/inward/record.url?scp=77955983893&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=77955983893&partnerID=8YFLogxK
U2 - 10.1016/j.bone.2010.05.024
DO - 10.1016/j.bone.2010.05.024
M3 - Article
C2 - 20641162
AN - SCOPUS:77955983893
VL - 47
SP - 256
EP - 262
JO - Bone
JF - Bone
SN - 8756-3282
IS - 2
ER -
