CHRONIC TREATMENT WITH CITALOPRAM INDUCES NORADRENALINE RECEPTOR HYPOACTIVITY - A MICRODIALYSIS STUDY

To investigate whether chronic citalopram administration influences th e cyclic AMP (cAMP) synthesis in vivo, microdialysis was used to asses s citalopram-induced alterations in extracellular concentrations of cA MP in the dorsal hippocampus of freely moving rats. Citalopram adminis tration for 4 weeks (40 mg/kg p.o. daily) did not affect the baseline levels of cAMP but decreased the noradrenaline-induced enhancement of cAMP levels. No change in forskolin-induced enhancement of cAMP levels was observed. Citalopram in situ did not exert any effect on the cAMP levels. These data support the hypothesis that chronic administration of antidepressants alters the function of noradrenergic receptors.