This experiment was performed to elucidate the effect of muscarinic cholinergic and adrenergic agonists that stimulate the Na+ -K+ ATPase of rat salivary glands. Parotid and submaxillary glands were removed under pentobarbital sodium anesthesia
and
then microsomal fraction of tissue homogenates was collected by a series of centrifugation. Experimental group was divided into agonist-treated(carbachol, norepinephrine and isoproterenol) and blocker-treated(atropine. Phentolamine and
propranolol)
groups. ATPase activity was estimated in the incubation medium containing 20mM Tris-HCl(pH 7.4), 3mM MgCl2, 100 mM NaCl, 30mM KCl and 3mM ATP. Incubation was carried out for 60 min in a water bath at 37℃with shaking and concentration of
inorganic
phosphate within the centrifuged microsome was measured by the method of Fiske and Subbarow at 570mm. Protein determination was made by the method of Lowry et al. There was no significant difference between parotid and submaxillary glands. And
There was
a dose-dependent increase in Na+ -K+ ATPase activity by carbachol and this was abolished by atropine. Norepinephrine markedly increased the activity of the Na+ -K+ ATP ase and this activating effect was diminished by phentolamine,α-adrenergic
blocking
drug. The Activity of Na+ -K+ ATPase was significantly increased by isoproterenol and but not abollshed by propranolol, β-adrenergic blocking drug.
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