Effect of apomorphine, a dopamine receptor agonist, on penile tumescence in normal subjects

https://doi.org/10.1016/0278-5846(84)90040-XGet rights and content

Abstract

1. Apomorphine HC1 (Apo) (0.25 0.5 or 0.75 mg sc), a dopamine (DA) receptor agonist, induced penile erections (PEs) (monitored by mercury strain gauges and continuous recording on paper strip charts) in 7 out of 9 normal subjects and placebo in 1 of these 9 (p < 0.05).

2. Apo-induced PEs recurred in each of the 6 subjects retested.

3. Benztropine (2 mg iv) had no effect on Apo-induced penile tumescence (PT).

4. These data suggest (a) DA mechanisms play a role in normal erectile function (b) DA-mediated PT is not modulated by cholinergic systems (c) evaluation of the erectile response to Apo may provide a simple ancillary test to the investigation of impotence and a way of identifying a subpopulation of impotent subjects with impaired DA function who may respond to long-acting DA agents (d) Apo-induced PT may provide a novel way of studying DA function in man.

References (22)

  • J. Bommer et al.

    Improved sexual function in male haemodialysis patients on bromocrip tine

    Lancet

    (1979)
  • N.P.V. Nair et al.

    Effect of sulpiride, an atypical neuroleptic, on apomorphine-induced growth hormone secretion

    Brain Res. Bull.

    (1982)
  • A. Benassi-Benelli et al.

    Penile erection induced by apomorphine and N-n-propyl-norapomorphine in rats

    Arch. Int. Pharmacodyn. Ther.

    (1979)
  • O. Benkert

    Pharmacotherapy of sexual impotence in the male

    Mod. Probl. Pharmacopsych.

    (1980)
  • O. Benkert et al.

    Effect of l-dopa on sexually impotent patients

    Psychopharmacologia (Berl.)

    (1972)
  • G.S. Brindley

    Cavernosal alpha-blockade: a new technique for investigating and treating erectile impotence

    Brit. J. Psychiat.

    (1983)
  • S. Lal

    Clinical studies with apomorphine

  • S. Lal et al.

    Apomorphine and psychopathology

    J. Neurol. Neurosurg. Psychiat.

    (1975)
  • S. Lal et al.

    Effect of methysergide and pimozide on apomorphine-induced growth hormone secretion in men

    J. Clin. Endocrinol. Metab.

    (1977)
  • S. Lal et al.

    Effect of naloxone or levallorphan on serum prolactin concentrations and apomorphine-induced growth hormone secretion

    Acta Psychiat. Scand.

    (1979)
  • S. Lal et al.

    Effect of domperidone on apomorphine-induced growth hormone secretion in normal men

    J. Neural Trans.

    (1982)
  • Cited by (95)

    • Male Sexual Behavior

      2015, Knobil and Neill's Physiology of Reproduction: Two-Volume Set
    • Central Nervous System Agents and Erectile Dysfunction

      2011, Urologic Clinics of North America
      Citation Excerpt :

      In one of the earliest clinical reports on the use of apomorphine, Lal and colleagues12 reported reproducible erections in 7 of 9 men injected subcutaneously with varying doses of the drug.

    • Future sexual medicine physiological treatment targets

      2010, Journal of Sexual Medicine
      Citation Excerpt :

      Dopamine agonists are perhaps the best known compounds that facilitate penile erection in male mammals, including man. Apomorphine is the best known dopaminergic agonist which is commercially available and labeled for the therapy of ED [33] activates dopamine receptors of the D2 family in order to facilitate penile erection[34–36]. Molecular biology studies have shown that D2 receptors may be divided into D2 (long and short variants), D3, and D4 receptor subtypes [37].

    • Pathways of sexual desire

      2009, Journal of Sexual Medicine
      Citation Excerpt :

      It is now generally acknowledged that DA agonists stimulate sexual excitement and arousal in both rats and humans, especially in circumstances where the expression of these appetitive behaviors is endogenously low. Although the general DA receptor agonist apomorphine stimulates penile erection in normally functioning male rats and men with erectile dysfunction [79,80], it has not been reported to affect measures of sexual desire in normally functional rats. However, the D2-selective agonist quinelorane activated copulation in sexually inactive male rats and reduced the ejaculatory threshold in males who copulated [81].

    View all citing articles on Scopus
    View full text