Behavior-associated changes in blood pressure during heroin self-administration

Pharmacol Biochem Behav. 1993 Nov;46(3):561-7. doi: 10.1016/0091-3057(93)90544-4.


Changes in arterial blood pressure (ABP) were studied in freely moving rats during the development and performance of operant IV heroin self-administration (SA) behavior (100 micrograms/kg/injection). Heroin SA was accompanied by bidirectional, phasic ABP fluctuations in the absence of significant alterations in long-term, basal ABP levels. In trained rats, ABP gradually increased starting 5 min before each lever-press for the drug, reached a peak at the moment of lever-press and abruptly decreased after heroin infusion. This biphasic pattern corresponded to a preresponding behavioral activation followed by a postheroin sedation. These ABP fluctuations were absent during the initial heroin self-injections in drug-naive rats and during the first self-injections of a session in trained rats. A slight hypo- and hypertension were seen in these cases, respectively. The postdrug ABP decrease became more pronounced after rats received a double dose of heroin. With training, nonreinforced lever-presses and sound stimulation previously associated with heroin self-injections also significantly decreased ABP. Thus, a gradual ABP increase appears to be an essential correlate of drug-seeking and -taking behavior, while a subsequent ABP decrease may be related to the alleviation of these behaviors by heroin and possibly correlate to its rewarding (euphorigenic) action.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Acoustic Stimulation
  • Animals
  • Behavior, Animal / drug effects
  • Behavior, Animal / physiology*
  • Blood Pressure / drug effects
  • Blood Pressure / physiology*
  • Conditioning, Operant / drug effects
  • Conditioning, Operant / physiology
  • Dopamine / metabolism
  • Heroin Dependence / physiopathology*
  • Heroin Dependence / psychology*
  • Male
  • Rats
  • Rats, Sprague-Dawley
  • Reinforcement, Psychology
  • Self Administration


  • Dopamine