Serum parathyroid hormone-related protein levels during lactation.
We measured parathyroid hormone-related protein (PTHrP) in the serum of 15 healthy women within three days of beginning breast-feeding and within one hour of completing nursing. A sensitive immunoradiometric assay that measures N-terminal PTHrP containing at least the first 74 amino acids was used. We found normal PTHrP values in all patients. Values one day before and two days after delivery in a hypoparathyroid woman who chose not to breast-feed were also normal. Since N-terminal PTHrP fragments of 1-36 amino acids or more are biologically active, we believe additional studies using sensitive PTHrP assays that measure smaller fragments and investigations performed under other conditions of breast-feeding are necessary before concluding that PTHrP does not have a role in calcium homeostasis in nursing mothers. Furthermore, additional studies in hypoparathyroid nursing mothers should be performed.
Caplan
R H
RH
Department of Laboratory Medicine, Gundersen/Lutheran Medical Center, La Crosse, Wisconsin, USA.
Wickus
G G
GG
Sloane
K
K
Silva
P D
PD
D002118:Calcium / Q000097:blood; D005260:Female; D006706:Homeostasis; D006801:Humans; D007011:Hypoparathyroidism / Q000097:blood; D015592:Immunoradiometric Assay; D007774:Lactation / Q000097:blood* / Q000502:physiology; D044162:Parathyroid Hormone-Related Protein; D011506:Proteins / Q000378:metabolism* / Q000502:physiology; D012016:Reference Values
C470121:PTHLH protein, human; D044162:Parathyroid Hormone-Related Protein; D011506:Proteins; D002118:Calcium