Lack of effects of neutralization of parathyroid hormone-related protein on calcium homeostasis in neonatal mice.
Large quantities of parathyroid hormone-related protein (PTHrP) are present in the milk of various species. It has been suggested that PTHrP may play a role in neonatal calcium homeostasis. In the present study we evaluated the effect of neutralization of amino-terminal PTHrP activity by passive immunization in 1-day-old mouse pups. Neutralization of amino-terminal PTHrP activity had no significant effect on serum calcium or whole-body calcium content in the neonatal mice. In additional studies, we demonstrated that subcutaneous administration of PTHrP-(1-34) increased serum calcium, whereas oral administration had no significant effect in 3-day-old pups. The studies therefore demonstrate that the amino terminus of PTHrP may not play a significant role in neonatal calcium homeostasis. Local effects of PTHrP cannot be excluded by the results of the present study.
Kukreja
S C
SC
Department of Medicine, VA West Side, Medical Center, Chicago.
D'Anza
J J
JJ
Melton
M E
ME
Wimbiscus
S A
SA
Grill
V
V
Martin
T J
TJ
D000284:Administration, Oral; D000818:Animals; D000831:Animals, Newborn; D002118:Calcium / Q000032:analysis / Q000097:blood* / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D006706:Homeostasis; D007106:Immune Sera / Q000378:metabolism; D007116:Immunization, Passive; D007279:Injections, Subcutaneous; D051379:Mice; D008815:Mice, Inbred Strains; D009363:Neoplasm Proteins / Q000008:administration & dosage / Q000378:metabolism / Q000494:pharmacology* / Q000502:physiology; D044162:Parathyroid Hormone-Related Protein; D010446:Peptide Fragments / Q000008:administration & dosage / Q000378:metabolism / Q000494:pharmacology* / Q000502:physiology; D011506:Proteins
D007106:Immune Sera; D009363:Neoplasm Proteins; D044162:Parathyroid Hormone-Related Protein; D010446:Peptide Fragments; D011506:Proteins; C054296:parathyroid hormone-related protein (1-34); D002118:Calcium