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Le bâillement, du réflexe à la pathologie
Le bâillement : de l'éthologie à la médecine clinique
Le bâillement : phylogenèse, éthologie, nosogénie
 Le bâillement : un comportement universel
La parakinésie brachiale oscitante
Yawning: its cycle, its role
Warum gähnen wir ?
 
Fetal yawning assessed by 3D and 4D sonography
Le bâillement foetal
Le bâillement, du réflexe à la pathologie
Le bâillement : de l'éthologie à la médecine clinique
Le bâillement : phylogenèse, éthologie, nosogénie
 Le bâillement : un comportement universel
La parakinésie brachiale oscitante
Yawning: its cycle, its role
Warum gähnen wir ?
 
Fetal yawning assessed by 3D and 4D sonography
Le bâillement foetal
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mise à jour du
15 janvier 2010
 
J Urol.
1998;160(2):389-393
Synthetic melanotropic peptide initiates erections
in men with psychogenic erectile dysfunction:
double-blind, placebo controlled crossover study
Wessells H, Fuciarelli K, Hansen J,
Hadley ME, Hruby VJ, Dorr R, Levine N
 
Department of Pharmacology, University of Arizona College of Medicine
Tucson, USA

Chat-logomini

PURPOSE: We evaluated the erectogenic properties of a new cyclic alpha-melanocyte-stimulating hormone analogue, Melanotan-II, to treat men with psychogenic erectile dysfunction.
 
MATERIALS AND METHODS: Ten men with erectile dysfunction of no known organic cause were entered in a double-blind, placebo controlled crossover study in which the erectogenic properties of Melanotan-II and a vehicle placebo were compared using real-time RigiScan monitoring. The presence, duration and rigidity of erections were recorded during a 6-hour period. RESULTS: In 8 of 10 men treated with Melanotan-II clinically apparent erections developed. Mean duration of tip rigidity greater than 80% was 38.0 minutes with Melanotan-II and 3.0 with placebo (p=0.0045). Transient side effects of nausea, stretching and yawning, and decreased appetite were reported more frequently after injections of Melanotan-II than placebo but none required treatment.
 
CONCLUSIONS: Melanotan-II is a potent initiator of erections in men with psychogenic erectile dysfunction and has manageable side effects at a dose of 0.025 mg./kg.
 
Episodes of penile erection, and the stretching and yawning syndrome can be induced in experimental animals by central nervous system administration of adrenocorticotropin and a-melanocyte-stimulating hormone (a-MSH)? Central dopaminergic and oxytocinergic receptors seem to mediate penile erection and yawning but the effects of adrenocorticotropin and a-MSH persist, despite administration of j antagonists to oxytocin and dopamine. This finding suggests that melanotropic peptides act downstream to the actions of dopamine and oxytocin.2
 
Melanotropin analogues have been developed to promote skin pigmentation. Melanotan-II, a superpotent cyclic melanotropic heptapeptide, caused penile erections in a pilot phase 1 clinical trial when administered subcutaneously to 3 normal men. We report the erectogenic properties and side effect profile of Melanotan-II in a double-blind, placebo controlled crossover study of 10 men with psychogenic erectile dysfunction.
 
...........
The side effects of nausea, stretching and yawning, and decreased appetite were more frequently reported after treatment with Melanotan-II than placebo. Men who reported moderate to severe nausea had received higher dosages of Melanotan-II than the less symptomatic group. At our preferred dose of 0.025 mg./kg. no subject reported moderate or severe adverse reaction. We believe that the stretching and yawning syndrome, noted in other species, occurs in humans in response to Melanotan-I1 but whether this is a direct effect of the peptide or a response to somnolence is unclear. Of note, the 2 patients who did not have erections did not report yawning or nausea. Finally, only 1 subject reported tanning but we did not perform photometric testing to confirm this finding nor did we control for sun exposure during the experimental period. In previous studies a cumulative dose of 0.1 mg./kg. Melanotan-II was required for an increase in skin pigmentation.5 Consideration of possible clinical applications of this new peptide is premature.
 
Further studies in a population with organic erectile dysfunction may define appropriate candidates for the use of Melanotan-II. The time to onset of erection in our study is long for a clinically useful drug but these patients were not exposed to erotic stimuli and use of the drug at home with sexual stimulation should lead to a more rapid response. We believe that nasal insufflation or other delivery systems may provide more rapid absorption and be more acceptable than subcutaneous injection of the drug.

Iatrogenic yawns