Erectile dysfunction equivalent to endothelial dysfunction?

The discovery of nitric oxide with its regulating properties of vascular tone played a pivotal role in the understanding of vascular physiology and opened unprecedented avenues for research in the development of many cardiovascular drugs. Nitric oxide released by vascular endothelial cells induces smooth and inhibits vascular smooth muscle proliferation. Nitric oxide exerts many of its effects by activation of soluble guanyl cyclase, resulting in increased production of cyclic guanosine monophosphate (cGMP), which results in lower intracellular calcium levels and therefore, vasodilatation. Nitric oxide is widely recognised as the most important factor involved in corpus cavernosal smooth muscle relaxation, and hence in erection. A correlation between erectile dysfunction and endothelial dysfunction in type II diabetic men is established, involving a defective nitric oxide activity, linked to reduced nitric oxide availability. canadian online pharmacy

The concentration of intracellular cGMP is regulated by the rates of production and elimination of cGMP. The rate of production is controlled through the nitric oxide-guanyl cyclase activity. The rate of elimination depends on the activity of phophodiesterase enzymes (PDE) responsible for the breakdown of cyclic nucleotides cAMP and cGMP. Four phosphodiesterase isoforms have been identified in human penile tissue (types 2, 3, 4, and 5); PDE-5 is the most important form of PDE in cavernosal smooth muscle. Inhibition of this enzyme by a PDE-5 inhibitor such as sildenafil (Viagra) enhances nitric oxide-induced vasorelaxation by increasing vascular smooth muscle cGMP concentration. Generic Sildenafil has been shown to be an effective oral treatment for erectile dysfunction in men, including men with diabetes. In a brachial artery flow-mediated dilatation study (FMD, a marker of endothelial function), the favourable short- and long-term effect of sildenafil on FMD was recendy demonstrated. The beneficial effect of prolonged cheap sildenafil therapy may have implications for management of erectile dysfunction as well as cardiovascular disease, especially in patients with diabetes. Just recently Halcox et al. studied the effects of the phophodiesterase inhibitor sildenafil on coronary and peripheral vascular function, platelet activation, and myocardial ischaemia. The authors concluded that sildenafil dilates epicardial coronary arteries, improves endothelial dysfunction and inhibits platelet activation in patients with coronary artery disease. 

Table 1. Patient’s attitudes toward discussions about sexuality (Bedell, et al.):

Women

Men

Should physicians talk with their patients about sexual functioning?

64

81

Is your doctor comfortable talking about sexual functioning?

28

52

Are you comfortable talking about sexual functioning?

42

73

Does your concern about confidentially of the medical record influence

6

9

your willingness to discuss sexuality with your doctor?
Should a healthcare professional other than a physician ask questions about sexuality?

10

23

Do you feel your physician has adequately informed you about your sexual functioning?

18

3

The concept of endothelial dysfunction leading to erectile dysfunction and eventually to coronary heart disease was heavily advocated during the International Summit on Sexual Medicine and Cardiology, Paris 2002. A clear relation between erectile dysfunction and cardiovascular disease such as hypertension, coronary artery disease and myocardial infarction is well documented. Cardiovascular disease is clearly underdiagnosed and ignored in men with erectile dysfunction. Montorsi et al. reported on 200 consecutive patients admitted with an acute coronary syndrome. In 70% of these patients erectile dysfunction was present before the clinical manifestation of coronary heart disease. ‘The Penile Stress test: a window to the hearts of men’ was the appealing title of an abstract presented at the American Heart Association by Pritzker et al. who reported on the presence of significant coronary heart disease in 40% of patients with ED. Recently, data were presented linking ED to other atherosclerotic diseases by showing a correlation between total coronary artery plaque burden as assessed angiographically and objective measures of ED. Buy cheap Levitra

All of the above underlines the importance of knowledge and awareness of erectile dysfunction as a potential marker for endothelial dysfunction by the cardiologist. Levitra Professional

Category: Erectile dysfunction

Tags: cardiovascular diseases, endothelium, men, prognosis, risk factors, sex

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