THE EFFECT OF POTASSIUM CHLORIDE INFUSION ON PAROTID SALIVARY FLOW AND COMPOSITION IN CONSCIOUS SHEEP

Abstract

The composition and flow of parotid saliva in conscious sheep was measured before, during and after the intravenous infusion of 0·43 M‐KCl or 0·43 M‐NaCl at 2 ml./min for 2 hr. The salivary flow rate was depressed during the infusion of potassium chloride into both intact sheep and adrenalectomized sheep. As the salivary flow was unchanged by sodium chloride infusion it was concluded that the potassium ion was responsible for the decrease in flow and that this effect was not mediated through any of the adrenal hormones. The highly significant negative correlation between plasma potassium concentration and salivary flow throughout all potassium infusions indicated that the extent to which the salivary flow was depressed varied with the degree of hyperkalaemia. Except for situations where mineralocorticoid levels were likely to be elevated the concentrations of sodium and potassium in the saliva were positively co‐related with the plasma concentrations of these ions. The salivary bicarbonate concentration was positively correlated with the salivary flow whereas the phosphate concentration of the saliva was negatively related to flow. The chloride concentration of the saliva was negatively correlated with salivary flow during all potassium chloride infusions. © 1975 The Physiological Society