Partial dissociation between salivary secretion and active potassium transport in the perfused cat submandibular gland.
Isolated cat submandibular glands were perfused with Locke solutions in a thermostated chamber. Passive loss of potassium and uptake of sodium was achieved either by increasing the permeability of the cell membranes by acetylcholine (ACh) or by inhibiting the sodium-potassium pump reversibly by cooling or by removal of extracellular potassium. Irrespective of the way by which the cells were potassium depleted and sodium loaded, re-establishment of normal conditions was sufficient to cause an active net uptake of potassium (probably coupled to net extrusion of sodium). However, while ACh-induced changes in intracellular concentrations of monovalent cations were accompanied by salivary secretion, virtually no secretion was observed when normal conditions were re-established after concentration changes caused by inhibiting the sodium-potassium pump. It is concluded that while the transport mechanisms responsible for the maintenaance of the intracellular concentrations of monovalent cations undoubtedly is a (Na+-K+)-activated ATPase, the transport mechanism responsible for the formation of the primary saliva is probably of a different type, since it apparently is not directly activated by the intracellular sodium concentration.
D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D001692:Biological Transport; D001693:Biological Transport, Active; D002415:Cats; D003080:Cold Temperature; D004558:Electric Stimulation; D011188:Potassium / Q000378:metabolism*; D012463:Saliva / Q000378:metabolism*; D012636:Secretory Rate; D012964:Sodium / Q000378:metabolism; D013363:Submandibular Gland / Q000378:metabolism*
D012964:Sodium; D000109:Acetylcholine; D011188:Potassium