D2 receptors in the paraventricular nucleus regulate genital responses and copulation in male rats

Pharmacol Biochem Behav. 1991 May;39(1):177-81. doi: 10.1016/0091-3057(91)90418-2.


The D2 dopamine receptor agonist quinelorane (LY-163502), microinjected into the paraventricular nucleus (PVN), affected genital response of restrained supine male rats in a biphasic dose-dependent fashion. A moderate dose (1 microgram) facilitated penile responses (intense erections and penile movements), and decreased the latency to the first response. A high dose of quinelorane (10 micrograms) facilitated seminal emission while inhibiting penile responses. The addition of the D1 antagonist SCH-23390 to the 1 microgram dose of quinelorane potentiated quinelorane's increase in seminal emission. We suggest that D1 receptors in the PVN may be antagonistic to D2 receptor-mediated seminal emission, and possibly also penile responses. In copulation tests 1 microgram quinelorane decreased mount latency, whereas 10 micrograms quinelorane increased mount and intromission latencies and slowed copulatory rate. Both 1 and 10 micrograms quinelorane, and also 1 and 10 micrograms of the mixed D1 and D2 agonist apomorphine, decreased the number of intromissions preceding ejaculation.

Publication types

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

MeSH terms

  • Animals
  • Apomorphine / pharmacology
  • Benzazepines / pharmacology
  • Copulation / drug effects*
  • Dose-Response Relationship, Drug
  • Drug Synergism
  • Estradiol / pharmacology
  • Female
  • Genitalia, Male / drug effects*
  • Male
  • Microinjections
  • Ovariectomy
  • Paraventricular Hypothalamic Nucleus / physiology*
  • Penile Erection / drug effects
  • Quinolines / pharmacology*
  • Rats
  • Receptors, Dopamine / drug effects*
  • Receptors, Dopamine D2


  • Benzazepines
  • Quinolines
  • Receptors, Dopamine
  • Receptors, Dopamine D2
  • Estradiol
  • Apomorphine
  • quinelorane