, Volume 77, Issue 4, pp 309–316

Characteristic behavioral alterations in rats induced by rolipram and other selective adenosine cyclic 3′,5′-monophosphate phosphodiesterase inhibitors

  • Helmut Wachtel
Original Investigations

DOI: 10.1007/BF00432761

Cite this article as:
Wachtel, H. Psychopharmacology (1982) 77: 309. doi:10.1007/BF00432761


The significance of a characteristic symptomatology (hypothermia, hypoactivity, forepaw shaking, grooming, head twitches) as a potential in vivo correlate of enhanced availability of brain adenosine cyclic 3′,5′-monophosphate (cAMP) was examined in rats following systemic administration of various doses of dibutyryladenosine cAMP (dBcAMP) or of the phosphodiesterase (PDE) inhibitors rolipram, Ro 20-1724, ICI 63-197, isobutylmethylxanthine (IBMX), theophylline, cartazolate, and papaverine. The various PDE inhibitors could be assigned to three groups according to the pattern of behavioral alterations they induced. Rolipram, Ro 20-1724, and ICI 63-197 (group 1) caused hypothermia, hypoactivity, forepaw shaking, grooming, and head twitches. All behavioral effects were mimicked by dBcAMP but not dBcGMP. The order of potency and effective dosage range to induce the behavioral alterations were, in descending order, rolipram (0.09–1453 μmol/kg IP), ICI 63-197 (0.48–119 μmol/kg IP), Ro 20-1724 (5.6-1438 μmol/kg IP), corresponding with the recently reported efficacy of the drugs to elevate rat brain cAMP in vivo. Comparatively high doses of the alkylxanthine PDE inhibitors IBMX and theophylline (group 2) caused hypothermia, forepaw shaking, grooming, and head twitches concomitantly with a decline of the motor stimulatory effect, suggesting enhanced availability of brain cAMP. The order of potency and the effective dosage range to induce the behavioral alterations were, in descending order, IBMX (28.1–113 μmol/kg IP) and theophylline (139–555 μmol/kg IP). The third group, papaverine (295–1179 μmol/kg IP) and cartazolate (21.5–345 μmol/kg IP), caused only hypothermia and hypoactivity. The differences in the behavioral pattern of the two latter groups of compounds in comparison with dBcAMP and the selective cAMP PDE inhibitors are discussed with regard to their additional interference with adenosine actions besides their nonselective PDE inhibitory action.

Key words

RolipramPhosphodiesterase inhibitorsCyclic nucleotidesLocomotor activityRectal temperatureForepaw shakingGroomingHead twitchesRat

Copyright information

© Springer-Verlag 1982

Authors and Affiliations

  • Helmut Wachtel
    • 1
  1. 1.Department of NeuropsychopharmacologySchering AGBerlin 65