Maringoni R L, Atta A G
Rev Bras Pesqui Med Biol. 1979 Apr;12(1):25-31.
In order to study the possibility of the existence of a threshold for the transport capacity for sodium by the salivary ducts of the dog's submandibular gland 10 mongrel dogs were rendered hypernatremic by the intravenous infusion of a hypertonic sodium solution. The main excretory duct was canulated and the vegetative branch of the chorda tympani nerve was maximally excited for 20-minute periods intercalated by similar periods of rest. A threshold for sodium transport was observed, dependent on the amount of sodium offered to the salivary ducts and on the salivary flow. This threshold is around 75 uEq/min with a flow of saliva of 1.3 ml per minute. The excretion of potassium in these experiments did not show a trend to reach a threshold.
