Prof. Dr.Mohamed Hamdy Abouel-Hassan

gastrointestinal systems (e.g., blurred v
tuberoinfundibular
indigestion) (Goldstein I et al, 1998).
ision,
Central Neurotransmitters and Neural Hormones
Review of literature
headache, facial f
A variety of neurotransmitters (dopamine, norepinephrine, 5-HT, and
oxytocin) and neural hormones (oxytocin, Prolactin) have been implicated in
regulation of sexual function. It is suggested that dopaminergic and
adrenergic receptors may promote sexual function and that 5-HT receptors
inhibit it [Foreman et al, (1989)].
Dopamine
There are many dopaminergic systems in the brain with ultrashort,
intermediate, and long axons. The cell bodies are located in the ventral
tegmentum, substantia nigra, and hypothalamus, one of which, the
system, secretes the dopamine into the portal hypophysial
vessels to inhibit Prolactin secretion (Ganong, 1999a). Five different
dopamine receptors have been cloned (D 1 to D 5), and several of these exist
in multiple forms (Ganong, 1999b). In men, apomorphine, which stimulates
both D 1 and D2 receptors, induces penile erection that is unaccompanied by
sexual arousal (Danjou et al, 1988). Dopamine agonists (apomorphine and
pergolide) and dopamine uptake inhibitors (nomifensine and bupropion)
have been reported to enhance sexual drive in patients (Jeanty et al, 1984).
In animal studies, selective activation of D 2 -dopaminergic receptors by the
systemic administration of agonists such as apomorphine and quinelorane
increases sexual behavior, and this effect can be counteracted by centrally
acting antagonists.
lushing,
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