Evidence that drugs increasing 5-hydroxytryptamine transmission block jumping but not wet dog shakes in morphine-abstinent rats: a comparison with clonidine

J Pharm Pharmacol. 1984 Jan;36(1):68-70. doi: 10.1111/j.2042-7158.1984.tb02995.x.


(+)-Fenfluramine, a 5-hydroxytryptamine (5-HT) releaser and uptake blocker, m-chlorophenylpiperazine (CPP), a 5-HT receptor agonist, and clonidine, an agonist at adrenoceptors, were studied for their ability to modify jumping and wet dog shakes in morphine abstinent rats. (+)-Fenfluramine and CPP blocked jumping with no effect on wet dog shakes whereas the reverse was true for clonidine. The results further show that 5-HT mechanisms are preferentially involved in the expression of jumping in morphine-abstinent rats.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Clonidine / pharmacology*
  • Fenfluramine / pharmacology
  • Humans
  • Male
  • Morphine / adverse effects*
  • Motor Activity / drug effects
  • Piperazines / pharmacology
  • Rats
  • Rats, Inbred Strains
  • Receptors, Serotonin / drug effects*
  • Substance Withdrawal Syndrome / prevention & control*


  • Piperazines
  • Receptors, Serotonin
  • Fenfluramine
  • Morphine
  • Clonidine
  • 1-(3-chlorophenyl)piperazine