vasoactive-intestinal-peptide and Priapism

It has been suggested that vasoactive intestinal polypeptide (VIP) may be involved in the nervous control of penile tumescence and erection. VIP ergic nerves are present in the human penis, especially around the prudendal arteries and the corpus cavernosum. However, we have shown that VIP is unlikely to be non-adrenergic, non-cholinergic inhibitory transmitter for penile erection. The aim of this presentation is also to analyse other neurotransmitters of penile erection. This included discussion on: 1. motor neurotransmission; 2. non-adrenergic, non-cholinergic inhibitory transmission; 3. endogenously formed relaxants in the corpus cavernosum; 4. involvement of endothelium-derived relaxing factor(s) and; 5. role of prostanoids in penile erection and others.

Topics: Alprostadil; Erectile Dysfunction; Humans; Male; Neurotransmitter Agents; Papaverine; Penile Erection; Priapism; Receptors, Adrenergic, alpha; Trazodone; Vasoactive Intestinal Peptide; Yohimbine

The article discusses drugs which promote erection when injected via the intracavernous (IC) route during consultation. The diagnostic and therapeutic applications in the treatment of impotence are discussed also. 25% of impotent patients noted an improvement after this treatment while 50% of patients suffering from impotence of psychological origin noted an improvement. Auto-injection is also discussed. IC treatment now seems justified in most cases which have not responded to traditional therapeutic approaches and this includes cases of psychological origin. Vasoactive drugs can be described as being inducers (use of these drugs induces a rigid erection, even in the presence of the doctor), facilitating drugs (which produce a rigid erection only if sexual stimulation is present also) and inhibitors (which stop the erection). The former group (which has papaverine as leader) produces a significant number of side effects, not least of these being priapism; there is a risk of lasting iatrogenic impotence which is not negligible. These risks are reduced considerably when one uses facilitating drugs which, although less powerful, suffice in treating a large proportion of cases of impotence. Papaverine can not be replaced as a diagnostic drug but facilitating drugs should be used first in therapy and inducers should be used only if these facilitating drugs have failed.

Topics: Adrenergic alpha-Antagonists; Erectile Dysfunction; Humans; Injections; Male; Papaverine; Phenoxybenzamine; Priapism; Prostaglandins E; Vasoactive Intestinal Peptide