Abstract

The rate of total secretion of saliva was measured over a 3-h period, under steady state conditions, in conscious sheep. The rates of secretion of magnesium and calcium in saliva represented 25-30% of the magnesium and calcium in the extracellular fluid. Since the large stores of intracellular magnesium are not readily mobilizable, the only readily available reserve of magnesium to maintain magnesium homeostasis is a little in bone. Thus, if magnesium ions from food and saliva are not adequately reabsorbed in the fore-stomachs, their loss could contribute significantly to the failure of homeostasis noted in acute ruminant hypomagnesaemia. Studies of the salivary clearance of 28 Mg showed a delay of 5-13 h in the time course of the salivary specific activity of 28 Mg, relative to that in plasma. This delay is indicative of transcellular interchange between magnesium ions in the central compartment, represented by the extracellular fluid, and an outer compartment which includes the salivary epithelial cells. Prolonged hypercalcaemia, caused by injections of 1 alpha (OH) cholecalciferol, was accompanied by a significant increase in the secretion rate of calcium in saliva but the secretion rate of magnesium was unchanged.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.