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Effect of an alpha-melanocyte stimulating hormone analog on penile erection and sexual desire in men with organic erectile dysfunction

      Abstract

      Objectives. To assess the safety, erectogenic properties, and effect on sexual desire of Melanotan II, a synthetic melanotropic initiator of erection, in men with erectile dysfunction and organic risk factors.
      Methods. Ten subjects were enrolled in a double-blind, placebo-controlled, crossover study. Melanotan II (0.025 mg/kg) and vehicle were each administered twice by subcutaneous injection; real-time RigiScan monitoring and a visual analog were used to quantify the erections during a 6-hour period. The level of sexual desire and side effects were recorded with a questionnaire.
      Results. Melanotan II initiated subjectively reported erections in 12 of 19 injections versus only 1 of 21 doses of placebo. The mean rigidity score of the responders was 6.9 on a scale of 0 to 10. The mean duration of tip rigidity greater than 80% was 45.3 minutes with Melanotan II versus 1.9 for placebo (P = 0.047). The level of sexual desire after injection was significantly higher after Melanotan II administration than after placebo. Nausea and stretching/yawning occurred more frequently with Melanotan II, and 4 of 19 injections were associated with severe nausea.
      Conclusions. The erectogenic properties of Melanotan II are not limited to cases of psychogenic erectile dysfunction; men with a variety of organic risk factors developed penile erections. The finding of increased sexual desire warrants further investigation of centrally acting agents on disorders of sexual desire.
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      References

        • Heaton J.P.W.
        • Adams M.A.
        • Morales A.
        A therapeutic taxonomy of treatments for erectile dysfunction.
        Int J Impot Res. 1997; 9: 115-121
        • Heaton J.P.W.
        • Morales A.
        • Adams M.A.
        • et al.
        Recovery of erectile function by the oral administration of apomorphine.
        Urology. 1995; 45: 200-206
        • Argiolas A.
        • Melis M.R.
        • Gessa G.L.
        Yawning and penile erection.
        Ann NY Acad Sci. 1988; 525: 330-337
        • Williams J.R.
        • Carter C.S.
        • Insel T.R.
        Partner preference development in female prairie voles is facilitated by mating or the central infusion of oxytocin.
        Ann NY Acad Sci. 1992; 652: 487-489
        • Thody A.J.
        • Wilson C.A.
        • Everard D.
        Facilitation and inhibition of sexual receptivity in the female rat by α-MSH.
        Physiol Behav. 1979; 22: 447-450
        • Wessells H.
        • Fuciarelli K.
        • Hansen J.
        • et al.
        Synthetic melanotropic peptide initiates erections in men with psychogenic erectile dysfunction.
        J Urol. 1998; 160: 389-393
        • Dorr R.T.
        • Lines R.
        • Levine N.
        • et al.
        Evaluation of Melanotan-II, a superpotent cyclic melanotropic peptide in a pilot phase-I clinical study.
        Life Sci. 1996; 58: 1777-1784
        • National Institutes of Health Consensus Development Panel on Impotence
        Impotence.
        JAMA. 1993; 270: 83-90
        • Rosen R.C.
        • Riley A.
        • Wagner G.
        • et al.
        The international index of erectile function (IIEF).
        Urology. 1997; 49: 822-830
        • Levine L.A.
        • Lenting E.L.
        Use of nocturnal penile tumescence and rigidity in the evaluation of male erectile dysfunction.
        Urol Clin North Am. 1995; 22: 775-788
        • Al-Obeidi F.
        • de la Castrucci A.M.
        • Hadley M.E.
        • et al.
        Potent and prolonged acting cyclic lactam analogues of α-melanotropin.
        J Med Chem. 1989; 32: 2555-2561
        • van der Kraan M.
        • Adan R.A.
        • Entwistle M.L.
        • et al.
        Expression of melanocortin-5 receptor in secretory epithelia supports a functional role in exocrine and endocrine glands.
        Endocrinology. 1998; 139: 2348-2355
        • Mountjoy K.G.
        • Robbins L.S.
        • Mortrud M.T.
        • et al.
        The cloning of a family of genes that encode the melanotropin receptors.
        Science. 1992; 257: 1248-1251
        • Chhajlani V.
        • Wikberg J.E.S.
        Molecular cloning and expression of the human melanocyte hormone receptor cDNA.
        FEBS Lett. 1992; 309: 417-420
        • Gantz I.
        • Yoshitaka K.
        • Tashiro T.
        • et al.
        Molecular cloning of a novel melanocortin receptor.
        J Biol Chem. 1993; 268: 8246-8250
        • Vergoni A.V.
        • Bertolini A.
        • Mutulis F.
        • et al.
        Differential influence of a selective melanocortin MC4 receptor antagonist (HS014) on melanocortin-induced behavioral effects in rats.
        Eur J Pharmacol. 1998; 362: 95-101
        • Goldstein I.
        • Lue T.F.
        • Padma-Nathan H.
        • et al.
        Oral sildenafil in the treatment of erectile dysfunction.
        N Engl J Med. 1998; 338: 1397-1404
        • Laumann O.
        • Paik A.
        • Rosen R.C.
        Sexual dysfunction in the United States.
        JAMA. 1999; 281: 537-544
        • Fan W.
        • Boston B.A.
        • Kesterson R.A.
        • et al.
        Role of melanocortinergic neurons in feeding and the agouti obesity syndrome.
        Nature. 1997; 385: 165-168