THE SECRETION OF PARATHYROID HORMONE-RELATED PROTEIN IN THE SALIVA OFSHEEP AND ITS EFFECTS ON THE SALIVARY CLEARANCE OF PHOSPHATE, CALCIUM, MAGNESIUM, POTASSIUM AND SODIUM-IONS

Parathyroid hormone-related protein (PTHrP(1-34)) was infused into fiv e sheep, each fitted with a large rumen cannula. After infusion, signi ficant increases were observed in the total and ionized calcium concen trations in plasma but not in saliva. In contrast, significant decreas es in the plasma concentrations of phosphate and potassium and corresp onding increases in their salivary concentrations and clearance rates were observed. The salivary concentration of endogenous PTHrP(1-34) wa s significantly greater than that in plasma sampled simultaneously, bu t during the infusion of PTHrP(1-34) both plasma and salivary concentr ations of PTHrP(1-34) increased.