Beta-adrenoceptor stimulation increases the pH of parotid acinar cells.
To characterize the effect of L-norepinephrine on intracellular pH (pHi) in parotid acinar cells, were measured the accumulation of 14C-labelled 5,5-dimethyloxazolidine-2,4-dione ([14C]DMO), in slices of parotid glands from Sprague-Dawley rats. L-Norepinephrine enhanced the [14C]DMO uptake in a concentration-dependent manner with half-maximal effect at about 1 microM and maximum effect at about 1 mM. The half-maximal effect corresponded to an increase in pHi by 0.08 units and was reduced by 2 microM L-propranolol (beta-adrenoceptor antagonist), but was not affected by 2 microM phentolamine (alpha-adrenoceptor antagonist). The results suggest that L-norepinephrine increases intracellular pH in rat parotid acini and that this effect may be mediated by beta-adrenoceptor stimulation.
D000318:Adrenergic beta-Agonists / Q000494:pharmacology*; D000818:Animals; D004114:Dimethadione / Q000378:metabolism; D005260:Female; D006863:Hydrogen-Ion Concentration; D009638:Norepinephrine / Q000494:pharmacology*; D010306:Parotid Gland / Q000187:drug effects* / Q000378:metabolism; D010646:Phentolamine / Q000494:pharmacology; D011433:Propranolol / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains
D000318:Adrenergic beta-Agonists; D011433:Propranolol; D004114:Dimethadione; D009638:Norepinephrine; D010646:Phentolamine