Adrenergic and cholinergic mediated glucose oxidation by rat parotid gland acinar cells during aging

Adrenergic (both α and β) and cholinergic agonists stimulated glucose oxidation in dispersed parotid acinar cells obtained from various aged rats. Basal levels of glucose oxidation were constant over the adult rat life span. Epinephrine and norepinephrine effects on parotid cell glucose oxidation were reduced about 50% in cells from 24 mo rats compared to results with 3 and 12 mo rats. The epinephrine effect was mediated primarily via the α-adrenergic system. In addition, an α-adrenergic agonist (phenylephrine) stimulated glucose oxidation significantly less in parotid cells from 24 mo rats than in those from younger rats. β-Adrenergic (isoproterenol) and cholinergic (carbachol) stimulation did not change with age. These results suggest that an age-related impairment occurs specifically in the α-adrenergic system of rat parotid acinar cells.