The secretion of parathyroid hormone‐related protein in the saliva of sheep and its effects on the salivary clearance of phosphate, calcium, magnesium, potassium and sodium ions

Abstract

SUMMARYParathyroid hormone-related protein (PTHrP(1-34)) was infused into five sheep, each fitted with a large rumen cannula. After infusion, significant increases were observed in the total and ionized calcium concentrations in plasma but not in saliva. In contrast, significant decreases in the plasma concentrations of phosphate and potassium and corresponding increases in their salivary concentrations and clearance rates were observed. The salivary concentration of endogenous PTHrP(1-34) was significantly greater than that in plasma sampled simultaneously, but during the infusion of PTHrP(1-34) both plasma and salivary concentrations of PTHrP(1-34) increased.

Immunolocalization of PTHrP in the parotid glands of three rodents species: Clethrionomys glareoulus, Microtus arvalis and white Swiss mice.

“…This has been confirmed by the findings reported by Dua et al [33] on the sheep salivary gland. These authors [33] observed after PTHrP infusion (1-34) a significant increase in the total and ionized calcium concentration in plasma but not in saliva.…”

“…This has been confirmed by the findings reported by Dua et al [33] on the sheep salivary gland. These authors [33] observed after PTHrP infusion (1-34) a significant increase in the total and ionized calcium concentration in plasma but not in saliva. In contrast, they noted a significant decrease in the plasma concentration of phosphate and potassium, and a corresponding increase in their salivary concentrations and clearance rates.…”

Serum concentrations of total and ionized calcium and magnesium and inorganic phosphate during Na2EDTA infusion in dairy cows

“…This effect may partly be a consequence of the infusion because a 0.9 % sodium chloride or a 5 % dextrose control solution alone induced hypophosphatemia (F enwick and D aniel 1992b, c). However, the increase of serum PTH concentration in response to the decrease of serum Ca (P otts et al 1968) may also be involved because PTH stimulates P i secretion in the saliva of sheep (C lark et al 1975; W right et al 1984; D ua et al 1995) and urine of sheep (B arlet and C are 1972) and cows (M ayer et al 1966, 1968). It is well established that the salivary route is the most important P i secretory pathway in ruminants (B reves and S chröder , 1991; C are 1994; B arlet et al 1995) whereby 1,25‐dihydroxyvitamin D (1,25‐(OH) 2 D) modulates this process in decreasing salivary P i (M anas ‐A lmendros et al 1982, R iad et al 1987).…”

Bone Biomarkers Measured on Salivary Matrix: Study of Biological Variability in a Cohort of Young Subjects

“…P1NP and TRAcP 5b [38] show high individuality (individuality index (II) < 0.6) equal to 0.12 and 0.56 respectively; the variation of values for each individual assessed occupies only a small part of the distribution of values for the whole group. In these cases, there is the risk of considering the value of an analyte in an individual to be improperly physiological and significantly far from its homeostatic set point but still included within the range of values obtained.…”

“…This observation has inspired various studies that have focused on the role of PTHrP in mediating osteoclastogenesis [37]. In subjects in the development age, the values on the biological variability of PTHrP in saliva, the low individuality, the higher critical difference with respect to the other evaluated biomarkers and the concentrations with secretion dynamics similar to those of the serum could be explained according to the constant local paracrine production related to the need for a regulatory mechanism on bone formation and tooth growth [35][36][37][38].…”