[Effect of parathyroid hormone-related protein on Na(+)-dependent phosphate transport in renal brush border membrane vesicles in rats].
Parathyroid hormone-related protein (PTHrP) has significant homology with parathyroid hormone (PTH) especially in the amino-terminal sequence. We compared some effects of human synthetic analogue of amino terminal PTHrP [hPTHrP (1-34)] with those of human synthetic analogue of amino terminal PTH [hPTH (1-34)]. Intravenous administration of hPTHrP (1-34) in parathyroidectomized rats caused hypercalcemic, hypophosphatemic and phosphaturic effects in the same degree of hPTH (1-34). In the kinetic study, apparent Km and Vmax of phosphate transport in renal brush border membrane vesicles were identical in both peptides (hPTHrP(1-34) Km = 27.6 +/- 0.8 mumol, Vmax = 3.78 +/- 0.04 nmol/mg.protein; hPTH(1-34) Km = 29.6 +/- 0.9 mumol, Vmax = 3.04 +/- 0.9 nmol/mg.protein). hPTHrP(1-34) and hPTH(1-34) were equipotent in eliciting a 9-fold increase of adenosine 3',5'-monophosphate (cAMP) production. These results demonstrate that the effect of hPTHrP (1-34) is similar to hPTH(1-34) on serum calcium, phosphorus and nephrogenous cAMP in vivo, and Na(+)-dependent phosphate transport in brush border membrane vesicles.
Saito
K
K
Department of Medicine, Juntendo University School of Medicine, Tokyo, Japan.
Hirano
K
K
Kubota
M
M
Tomino
Y
Y
Koide
H
H
D000818:Animals; D001692:Biological Transport; D007684:Kidney Tubules / Q000378:metabolism* / Q000648:ultrastructure; D008297:Male; D008871:Microvilli / Q000378:metabolism; D010281:Parathyroid Hormone / Q000494:pharmacology*; D044162:Parathyroid Hormone-Related Protein; D010446:Peptide Fragments / Q000494:pharmacology*; D010710:Phosphates / Q000378:metabolism*; D011506:Proteins / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D012964:Sodium / Q000502:physiology*; D019379:Teriparatide
D010281:Parathyroid Hormone; D044162:Parathyroid Hormone-Related Protein; D010446:Peptide Fragments; D010710:Phosphates; D011506:Proteins; D019379:Teriparatide; C054296:parathyroid hormone-related protein (1-34); D012964:Sodium