erectile dysfunction

The relaxation/erectile mechanisms of tetrandrine (Chinese herb Fen Fang Ji)

Spence — Fri, 05 Jun 2009 22:25:35 -0600

Conclusion: Tetrandrine, the main active ingredient in the Chinese herb Fen Fang Ji (the safe Fang Ji), has shown to relax penis muscles for enhanced blood flow to erectile tissue. It's mode of action is through Ca channel blocking, not nitric oxide pathways (which is the mechanism of viagra).

Nat Prod Res. 2009;23(2):112-21. Chen J, Liu J, Wang T, Xiao H, Yin C, Yang J, Chen X, Ye Z.Department of Urology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.

The relaxation mechanisms of tetrandrine (Tet) on the rabbit corpus cavernosum tissue in vitro were investigated. Strips of rabbit corpus cavernosum were mounted in organ chambers. The effects of Tet were examined on isolated muscle strips pre-contracted with phenylephrine (PE) alone, in the presence of N(W)-nitro-L-arginine (LNNA, a nitric oxide synthase inhibitor), 1-H-[1,2,4]oxadiazolo[4,3-alpha]quinoxalin-1-one(ODQ, a guanylyl cyclase inhibitor), indomethacin (cyclooxygenase inhibitor), tetraethylammonium (TEA, Ca(2+)-activated K(+) channel blocker), 4-aminopiridine (4-AP, voltage dependent K(+) channel blocker) and glibenclamide (ATP sensitive K(+)channel blocker). The effects of Tet on KCl-induced contraction of isolated muscle strips were also investigated. The procedure of calcium absence-calcium addition was designed to observe the effect of Tet on the two components of the contractile responses to PE based on the source of Ca(2+) (extracellular vs. intracellular). Corpus cavernosum strips showed relaxation in response to Tet (10(-8) approximately 10(-3) mol L(-1)) in a concentration-dependent manner with an IC(50) of 3.73 x 10(-5) mol L(-1). However, they were not affected by LNNA, ODQ, indomethacin and K(+)-channel blockers. Tet (10 micromol L(-1), 30 micromol L(-1)) concentration dependently reduced the maximal contraction response of isolated strips induced by KCl to (73.0 +/- 3.8) and (41.5 +/- 3.4)%, respectively (p < 0.01). In the procedure of calcium absence-calcium addition, Tet 100 micromol L(-1) inhibited both intracellular calcium-dependent and extracellular calcium-dependent contraction induced by PE (20 micromol L(-1)) (p < 0.05). The inhibition ratios were (23.8 +/- 7.1) and (40.7 +/- 11.2)%, respectively. The results of the present study suggest that Tet possesses a relaxant effect on rabbit corpus cavernosum tissues, which is attributable to the inhibition of extracellular Ca(2+) influx and the inhibition of release of intracellular-stored Ca(2+), but not mediated by the release of nitric oxide, prostaglandins or by the activation of potassium channels.

Effect of Shi Chuang Zi plant-extract (osthole) on erectile tissue

Spence — Fri, 05 Jun 2009 22:15:42 -0600

Conclusion: Cnidium Monnieri (Shi Chuang Zi) naturally increases nitric oxide release, which powerfully increases the production of cGMP. Cyclic Guanosine Monophosphate (cGMP) is the key in obtaining and sustaining a powerful erection. cGMP relaxes the muscles around the penis, which makes it possible for the cells in the penis to take in blood, thus allows you to experience a proper erection.

Chen J, Chiou WF, Chen CC, Chen CF. Institute of Clinical Medicine, National Yang-Ming University, and National Research Institute of Chinese Medicine, Taipei, Taiwan, Republic of China.

PURPOSE: We investigated the cavernosal relaxant effect of osthole, a coumarin isolated from Cnidium monnier (L.) Cusson which has been long used in China as a herbal medicine to improve male sexual dysfunction. MATERIALS AND METHODS: Strips of rabbit corpus cavernosum were precontracted with phenylephrine. Corporal relaxation evoked by osthole was then determined in the absence and presence of nitric oxide synthase inhibitor (L-NAME), soluble guanylate cyclase inhibitor (ODQ), cyclooxygenase inhibitor (indomethacin), tetradotoxin, and after endothelium deprivation. RESULTS: Corpus cavernosal strips showed relaxation in response to osthole (0.1 approximately 30 microM) in a dose-dependent manner. These effects were reduced partially but significantly by pretreatment with L-NAME, ODQ and by endothelial disruption. However, they were not affected by indomethacin and tetradotoxin treatment. Osthole pretreatment (from 1 to 30 microM) enhanced the sodium nitroprusside (0.3 microM)-induced relaxation of corpus cavernosum in a dose-dependent manner to a maximum of 3 times the pretreatment level at 30 microM osthole. However, this effect was abolished in the presence of zaprinast. Additionally, a higher concentration of osthole (30 microM) also enhanced forskolin-induced relaxation. CONCLUSION: The data suggested that osthole possesses a relaxant effect on rabbit corpus cavernosal tissues which is attributable to the release of NO from sinusoidal endothelium and to the potentiation of the cGMP and/or cAMP signal mediating relaxation of cavernosal smooth muscle by inhibiting phosphodiesterase.

Acupuncture in the treatment of psychogenic erectile dysfunction: first results of a prospective randomized placebo-controlled s

admin — Wed, 21 May 2008 01:18:53 -0600

Engelhardt PF, Daha LK, Zils T, Simak R, Konig K, Pfluger H.

Department of Urology and Ludwig-Boltzmann-Institute of Andrology and Urology, Lainz Hospital, Vienna, Austria. paul.engelhardt@aon.at

In a prospective study, we investigated the potentially curative effect of acupuncture in patients with psychogenic erectile dysfunction (pED). A total of 22 patients with pED were randomized into two groups. They were either treated with acupuncture specific against ED (treatment group) or acupuncture specific against headache (placebo group). Nonresponders of the placebo group were crossed over to the treatment group. Prior to acupuncture, serum sexual hormone levels, IIEF score, nocturnal penile tumescence testing for three nights (Rigiscan) and the erectile response to 50 mg sildenafil were evaluated. Out of 21 patients, 20 completed the study, including 10 patients after crossover. A satisfactory response was achieved in 68.4% of the treatment group and in 9% of the placebo group (P=0.0017). Another 21.05% of the patients had improved erections, that is, sufficient rigidity under simultaneous treatment with 50 gm sildenafil. The results of our pilot study indicate that acupuncture can be an effective treatment option in more than two-thirds of patients with psychogenic erectile dysfunction.

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How, why and when should urologists evaluate male sexual function?

admin — Wed, 21 May 2008 00:55:16 -0600

Droupy S, Ponsot Y, Giuliano F.

S Droupy and Y Ponsot are both Associate Professors of Urology at the University of Sherbrooke Medical School, Quebec, Canada.

Male sexual dysfunction-a term that is commonly used to refer to erectile dysfunction, premature ejaculation, decreased libido and impaired orgasm-is the primary complaint encountered by many urologists. Despite the high prevalence and bothersome nature of these complaints, they are frequently neglected in clinical practice. This paper highlights clinical situations in which urologists should systematically evaluate male sexual functioning. These include men who present with several common urologic disorders, such as pelvic trauma, malignancies, and lower urinary tract symptoms associated with benign prostatic hyperplasia, neurologic disorders and infertility. Studies have shown that erectile dysfunction might be a clinical marker of endothelial dysfunction, and consequently of undetected diabetes, hypertension, dyslipidemia, coronary artery disease and depression. We also address the question of whether urologists should adopt wide-ranging screening regimens for sexual dysfunction.

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Mechanisms of Disease: new insights into the cellular and molecular pathology of Peyronie's disease.

admin — Wed, 21 May 2008 00:54:24 -0600

Gonzalez-Cadavid NF, Rajfer J.

Department of Urology, David Geffen School of Medicine at UCLA, USA. ncadavid@ucla.edu

Peyronie's disease (PD) is characterized by fibrotic plaques in the penile tunica albuginea that cause curvature of the erect penis, and is often accompanied by pain and/or erectile dysfunction. This condition affects up to 9% of men. Treatment is mainly surgical, as pharmacologic therapy has limited efficacy. The pathophysiology of PD is poorly understood, but development of two rat models, extrapolation of what is known about the molecular pathology of other fibrotic conditions, and emphasis on the role of myofibroblasts and adult stem cells are helping to clarify etiology and identify new pharmacologic targets. Recent studies demonstrate a role for oxidative stress and cytokine release-primarily transforming-growth-factor beta1-in development of PD fibrotic plaques. There is evidence indicating that these profibrotic factors interact with antifibrotic defense mechanisms, such as decrease of myofibroblast accumulation, elimination of reactive oxygen species by inducible nitric oxide synthase and neutralization of transforming-growth-factor beta1 by decorin, such that some plaques are in dynamic turnover. Injury to the erect penis is thought to trigger PD by inducing extravasation of fibrin and subsequent synthesis of transforming-growth-factor beta1. Despite the lack of statistical support for a causal association between trauma and PD, it is possible that undetected microtrauma is involved. It is not known whether ossification of PD plaques is linked to fibrosis progression or is a manifestation of an alternative pathway. Both processes seem to be related to activation of fibroblast/myofibroblast differentiation in the tunica albuginea and to osteogenic commitment of stem cells in this tissue.

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Do motorcyclists have erectile dysfunction? A preliminary study

admin — Wed, 21 May 2008 00:53:41 -0600

Ochiai A, Naya Y, Soh J, Ishida Y, Ushijima S, Mizutani Y, Kawauchi A, Miki T.

Department of Urology, Kyoto Prefectural University of Medicine, Kyoto, Japan.

The aim of the present study was to evaluate the relationship between motorcycling and erectile dysfunction (ED). We investigated the relationship between motorcycling and erectile function using the 5-items version of the International Index of Erectile Function (IIEF5) in 234 motorcyclists (response rate 75%) and 752 healthy controls (response rate 66%). In all, 161 (69%) of 234 motorcyclists were diagnosed as ED based on IIEF5. The prevalence of ED in the motorcycle group increased by age as: 58, 63, 76 and 93%, for motorcyclists in 20-29, 30-39, 40-49 and 50-59 years, respectively. There was a significant difference in the prevalence of ED between the motorcycle group and the control group in all age groups. On stepwise logistic regression analysis, motorcycling was the strongest risk factor for ED. Although the severity of ED in motorcyclists was not so severe,
motorcycling may be one of risk factors for ED. International Journal of Impotence Research advance online publication 2 February 2006;

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Acupuncture in the treatment of psychogenic erectile dysfunction: first results of a prospective randomized placebo-controlled..

admin — Wed, 21 May 2008 00:52:01 -0600

Engelhardt PF, Daha LK, Zils T, Simak R, Konig K, Pfluger H.

Department of Urology and Ludwig-Boltzmann-Institute of Andrology and Urology, Lainz Hospital, Vienna, Austria. paul.engelhardt@aon.at

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