Differences in the response to intact b-PTH I-84 and synthetic b-PTH I-34 in isolated perfused bones from young and adult dogs.
Controversy exists over the relative effects of intact b-PTH I-84 and synthetic b-PTH I-34 on the generation of cyclic-AMP (cAMP) by the skeleton. Some experimental models demonstrate that these parathyroid hormone (PTH) peptides are equipotent while other systems show that the synthetic amino-terminal PTH fragment is more potent. The present studies examine the release of cAMP by isolated perfused bone from adult and young dogs in response to intact PTH I-84 and synthetic b-PTH I-34 in order to examine if age is important in determining the response of bone to PTH peptides. The results show that there is a remarkable difference in the release of cAMP between bones from adult and young animals. The release of cAMP in response to synthetic b-PTH I-34 is greater in bones from puppies than in bones from adult dogs. The release of cAMP in response to b-PTH I-84 is minimal in bones from adult dogs which is in agreement with previous studies from our laboratory. In puppies, however, there is a definite response to b-PTH I-84 albeit less than that of synthetic b-PTH I-34.
Galceran
T
T
Department of Internal Medicine, Washington University School of Medicine, St. Louis, Missouri 63110.
Slatopolsky
E
E
Martin
K J
KJ
D000375:Aging; D000818:Animals; D001846:Bone Development; D001842:Bone and Bones / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D000242:Cyclic AMP / Q000378:metabolism; D004285:Dogs; D007700:Kinetics; D010281:Parathyroid Hormone / Q000494:pharmacology*; D010446:Peptide Fragments / Q000494:pharmacology*; D019379:Teriparatide
D010281:Parathyroid Hormone; D010446:Peptide Fragments; D019379:Teriparatide; D000242:Cyclic AMP