3H-Noradrenaline and 3H-5-hydroxytryptamine release from rat brain slices and its presynaptic alpha-adrenergic modulation after long-term desipramine pretreatment

Naunyn Schmiedebergs Arch Pharmacol. 1982 Feb;318(3):173-80. doi: 10.1007/BF00500477.


The electrically-evoked release of 3H-noradrenaline from superfused cortex and hippocampus slices was strongly enhanced (by about 50%) after long-term (4 weeks) pretreatment with desipramine (10 mg/kg, twice daily). The release-enhancing effect of the alpha-receptor antagonist phentolamine was significantly reduced but the inhibitory effects of exogenous noradrenaline and clonidine on 3H-noradrenaline release were virtually unchanged after chronic desipramine treatment. The K+ -induced release of 3H-noradrenaline from superfused synaptosomes obtained from rats pretreated with desipramine was about 25% higher than that from synaptosomes of control animals. However, noradrenaline inhibited the K+ -induced synaptosomal 3H-noradrenaline release to the same extent (viz. by about 55%) in both cases. The release of 3H-5-hydroxytryptamine induced by 26 mM K+ from cortex and hippocampus slices was not affected by chronic pretreatment with desipramine. In addition, no change was observed in the inhibitory effect of noradrenaline o 3H-5-hydroxytryptamine release. It is concluded that long-term pretreatment with desipramine leads to selective changes in the basic mechanism(s) of noradrenaline release rather than to changes in the sensitivity of presynaptic alpha-adrenoceptors.

MeSH terms

  • Animals
  • Brain / metabolism*
  • Desipramine / pharmacology*
  • Electric Stimulation
  • In Vitro Techniques
  • Male
  • Norepinephrine / metabolism*
  • Phentolamine / pharmacology
  • Rats
  • Rats, Inbred Strains
  • Receptors, Adrenergic / physiology*
  • Receptors, Adrenergic, alpha / physiology*
  • Serotonin / metabolism*
  • Synaptosomes / metabolism
  • Time Factors


  • Receptors, Adrenergic
  • Receptors, Adrenergic, alpha
  • Serotonin
  • Desipramine
  • Norepinephrine
  • Phentolamine