MODIFICATION OF THE DOPAMINE AND NORADRENALINE CONTENT IN RAT CAROTID-BODY BY CARBOHYDRATE-ACTIVE STEROIDS

Short-term or long-term administration of dexamethasone (1 mg/kg, i.p.) increases the concentrations of both dopamine and noradrenaline in rat carotid body. This increase in catecholamine content elicited by dexamethasone also occurs after transection of th. carotid sinus nerve or removal of the superior cervical ganglion. Injections of cycloheximide curtail the dexamethasoneinduced increase in noradrenaline content but the increase in dopamine content remains unchanged. The rate of elimination of dihydroxyphenylacetic acid is decreased by more than 50% 12 h following the injection of dexamethasone, while the steady-state content of dopamine is increased. It is inferred that the increase in dopamine content is due to a reduction of dopamine metabolism. The long-term increase in noradrenaline content appears to be triggered by a mechanism that depends on new protein synthesis. © 1979.