ausblenden:
Schlagwörter:
-
Zusammenfassung:
In order to test the hypothesis that pharmacological stimulation of salivary glands resulted in stimulation of electrolyte transport, not only in the primary secretion but also in the secondary ductal modification, experiments were undertaken involving micro perfusion of the submaxillary main duct. From in vivo experiments in rats it was found that both sympathomimetic and parasympathomimetic stimulation resulted in a sharp increase in the rate of ductal bicarbonate secretion under all circumstances studied. When the luminal sodium chloride concentration was low, this stimulated increase in bicarbonate secretion was accompanied by a parallel increase in ductal potassium secretion, but when the sodium chloride concentration was high, the transport of sodium and potassium was actually inhibited to some extent and bicarbonate was secreted partially in exchange for chloride.
In vitro experiments with the main duct of the rabbit submaxillary gland show that carbachol is an effective inhibitor of sodium reabsorption at concentrations of 10−7 m. Unfortunately the rabbit submaxillary main duct transports so little potassium and bicarbonate that a stimulatory effect on transport of these substances is not noticeable. The action of carbachol can be blocked competitively with atropine and the action of isoproterenol with propranolol.
The results support the view that pharmacological stimulation can act to increase ductal electrolyte transport in the striated and excretory ducts of the rat submaxillary gland.
