All NOS subtypes produce NO, but each may play a different biologic role in various tissues. nNOS and eNOS are considered constitutive forms because they share biochemical features: They are calcium-dependent, they require calmodulin and reduced nicotinamide adenine dinucleotide phosphate for catalytic activity, and they are competitively inhibited by arginine derivatives. nNOS is involved in the regulation of neurotransmission, and eNOS is involved in the regulation of blood flow.

Erectile dysfunction (ED) is one of the most common conditions affecting middle-aged and older men. Nearly every primary care physician, internist and geriatrician will be called upon to manage this condition or to make referrals to urologists, endocrinologists and cardiologists who will assist in the treatment of ED. This article will briefly discuss the diagnosis and management of ED. In addition, emerging concepts in ED management will be discussed, such as the use of testosterone to treat ED, the role of the endothelium in men with ED and treating the partner of the man with ED. Finally, future potential therapies for ED will be discussed.
Normal erectile function depends on the release of NO and endothelial-dependent vasodilation of the penile arteries. The ‘artery size’ hypothesis, first described by Dr Montorsi, offers an explanation why men are more likely to develop ED before a myocardial infacrtion. It is believed that atherosclerosis affects all vascular beds equally but smaller arteries are more likely to become occluded than larger arteries.31 32 The penile arteries are 1–2 mm while the coronary arteries are 3–4 mm. Thus, the same degree of endothelial dysfunction and atherosclerosis is more likely to occlude blood flow in the penile arteries compared with the coronary arteries. The penile arteries therefore serve as a sensitive indicator for subsequent CVD. This theory is supported by the fact that ED occurs approximately 3 years prior to cardiac symptoms in virtually all patients with chronic coronary syndrome whereas patients with acute coronary syndrome have a much lower prevalence of sexual dysfunction.32
Treatments include psychotherapy, adopting a healthy lifestyle, oral phosphodiesterase type V (PDE5) inhibitors (Viagra, Levitra, Cialis, Stendra, and Staxyn), intraurethral prostaglandin E1 (MUSE), intracavernosal injections (prostaglandin E1 [Caverject, Edex], Bimix and Trimix), vacuum devices, penile prosthesis and vascular surgery, and (in some cases) changes in medications when appropriate.
The U.S. FDA (Food and Drug Administration) has a list of 29 OTC products that claim to treat erectile dysfunction. Patients should avoid these because many contain harmful ingredients. Other natural or herbal remedies such as DHEA, L-arginine, ginseng, and yohimbe are supplements that have been used but have not been proven safe and effective according to some researchers. Before using such compounds, individuals should consult their doctor. According to some experts, acupuncture does not effectively treat erectile dysfunction. Other home remedies for reducing ED symptoms include diet changes such as eating blueberries and citrus fruits and drinking red wine.
Since the advent of PDE5i, many other selective and non-selective peripheral acting compounds have been developed or are in development. Avanafil has shown promising results in treating ED in post-prostatectomy patients with suspected cavernous nerve injury (111). Other PDE5i marked in Asia such as udenafil, and mirodenafil also effective at treating ED may minimize side effects due to shorter half-lives (112-114). Soluable guanylate-cyclase inhibitors and potassium channel activators are compounds that have induced erections in animal models but remain experimental requiring further investigation (115-117).
Multiple combinations of intracavernosal therapy exist and the effectiveness of them varies based on patient characteristics and varying dosing strength (Table 1). Combination therapy have been extremely effective in the SCI population, and have several advantages including a reduction in cost per dose and side effects base on the lowered dose of each component (101,102). Effectiveness of combination therapy in the spinal cord population is well established, but no specific dose recommendations can be made based on the data (103-106). The use of combination therapy on other forms of neurogenic ED have not been well studied, but there use can be trialed as second-line therapy, or for populations were the side effects of PDE5i may preclude use such as in MSA due to hypotension.
You’ve probably heard of Viagra, but it’s not the only pill for ED. This class of drugs also includes Cialis, Levitra,  Staxyn, and Stendra. All work by improving blood flow to the penis during arousal. They're generally taken 30-60 minutes before sexual activity and should not be used more than once a day. Cialis can be taken up to 36 hours before sexual activity and also comes in a lower, daily dose. Staxyn dissolves in the mouth. All require an OK from your doctor first for safety.
It is common for a healthy older man to still want sex and be able to have sex within appropriate limitations. Understanding what is normal in older age is important to avoid frustration and concern. Older men and their partners often value being able to continue sexual activity and there is no age where the man is ‘too old’ to think about getting help with his erection or other sexual problems.
Monitoring erections that occur during sleep (nocturnal penile tumescence) can help you and your doctor to understand if the erectile dysfunction is due to psychological or physical causes. The nocturnal penile tumescence test is a study to evaluate erections at night. Normally men have three to five erections per eight hours of sleep. The test can be performed at home or in a sleep lab. The most accurate way to perform the test involves a special device that is connected to two rings. The rings are placed around the penis, one at the tip of the penis and the other at the bottom (base) of the penis. The device records how many erections occur, how long they last, and how rigid they are. The test is limited in that it does not assess the ability to penetrate.
2 inability of the adult male to achieve or sustain a penile erection or, less commonly, to ejaculate after achieving an erection. Several forms are recognized. Functional impotence has a psychological basis. Organic impotence includes vasculogenic, neurogenic, endocrinic, and anatomical factors. Anatomical impotence results from physically defective genitalia. Atonic impotence involves disturbed neuromuscular function. Poor health, old or advancing age, drugs, smoking, trauma, and fatigue can induce impotence. Also called erectile dysfunction, impotency. impotent, adj.
Medical conditions, such as hypertension, diabetes mellitus, and cardiovascular disease (CVD), and psychological conditions, such as depression and anxiety, also contribute to sexual dysfunction in middle-aged or elderly men. CVD and hypertension cause a narrowing and hardening of the arteries, leading to reduced blood flow to the corporal bodies, which is essential for achieving an erection. Diabetes is a common aetiology of sexual dysfunction, because it can affect both the blood vessels and the nerves that supply the penis. Men with diabetes are four times more likely to experience ED, and on average, experience ED 15 years earlier than men without diabetes.7 Obesity is also correlated to the development of several types of dysfunction, including a decrease in sex drive and an increase in episodes of ED.8
Another tip is to make sure you communicate with your partner what you like during the process of sex.  Many men are not communicative about what really turns them on.  If you are not aroused by what is going on, then you might experience ED.  Make sure you tell your partner what turns you on.  Communicating about intimacy should also lead to feeling more connected with your partner aiding in relaxing when you are sexual together.
"For men who are unwilling or unable to self-inject alprostadil, the FDA has approved this dissolvable pellet that can be inserted directly into the urethra, the opening of the penis," says Dr. Feloney. MUSE, with an inspiring name that actually stands for medicated urethral system for erection, will trigger an erection in about 10 minutes that may last as long as an hour. Using MUSE to treat ED can result in somewhat unpleasant side effects, however — including an aching sensation, burning, redness, and minor bleeding.
Before pursuing ED treatments, though, bear in mind that improving heart health by losing weight, eating a healthier diet, exercising more and quitting smoking typically enhances erectile performance as well as one’s overall health. In addition, sex therapy counseling sessions can often ease or eradicate ED symptoms, if the underlying cause is psychological in nature, says Drogo Montague, M.D., director of the Center for Genitourinary Reconstruction at the Cleveland Clinic. 
The truth is medication or psychosexual counselling are the first treatments a doctor will suggest because they’ve been proven to work. If a doctor has approved a medication for you then it’s safe. If you would still like to see if herbal supplements work for you, then there is a list below of supplements thought to work for erectile dysfunction. Just before you invest your money in them, remember they aren’t proven to work:
It appears that testosterone has NOS-independent pathways as well. In one study, castrated rats were implanted with testosterone pellets and then divided into a group that received an NOS inhibitor (L-nitro-L-arginine methyl ester [L-NAME]) and a control group that received no enzyme. [24] The castrated rats that were given testosterone pellets and L-NAME still had partial erections, a result suggesting the presence of a pathway independent of NOS activity.
It is normal for a man to have five to six erections during sleep, especially during rapid eye movement (REM). Their absence may indicate a problem with nerve function or blood supply in the penis. There are two methods for measuring changes in penile rigidity and circumference during nocturnal erection: snap gauge and strain gauge. A significant proportion of men who have no sexual dysfunction nonetheless do not have regular nocturnal erections.

Diabetes is an example of an endocrine disease that can cause a person to experience impotence. Diabetes affects the body’s ability to utilize the hormone insulin. One of the side effects associated with chronic diabetes is nerve damage. This affects penis sensations. Other complications associated with diabetes are impaired blood flow and hormone levels. Both of these factors can contribute to impotence.
Clearly, PDE5i have revolutionized the treatment of ED in general and the neurogenic ED population is no exception. They remain safe and effective in most men with neurogenic ED; however, care must be taken in prescribing PDE5i to men high spinal cord lesions, MSA or possibly PD. VEDs are minimally-invasive and can be as effective as other modalities at leading to erection. However, high discontinuation rates are associated with VED use related to pain, difficulty using the device or cold penis. Intracavernosal therapy has been a mainstay of treatment for neurogenic ED and remains extremely successful in the SCI population. Trial of intracavernosal therapy for other causes of neurogenic ED can be considered second-line therapy, but there is a relative paucity of data for clinical outcomes related to its use outside of SCI men. Surgical therapy via penile implantation remains another second line approach and may also be utilized to assist men with bladder management. Higher complication rates of infections, and perforation have been reported compared to neurologically intact men. Many other compounds are currently being evaluated for the treatment of neurogenic ED as well as gene and stem cell therapy, but still should be considered investigational until substantiated by randomized controlled trials.

Several pre-treatment factors have been described that may indicate success with PDE5i therapy. The presence of an upper motor neuron lesion up to T12 suggests a successful response, as well as requirement for a lower dosage of medication (62,68-71). Additionally, the presence of residual erections after injury or an incomplete SCI (ASI-A vs. ASIB-D) also improve the chance of PDE5i treatment success (59,67,68,71).

Sildenafil has been previously suggested as a treatment option for ED in men with epilepsy (77,78). However, Matos et al. warned that PDE5i are potentially pro-convulsant and should be used with great caution in men with epilepsy (79). Animal studies in rat and mice overwhelmingly suggest PDE5i can reduce seizure threshold. In human trials, seizures were rare but reported. PDE5i exerted their proconvulsive effect by lower seizure threshold possibly by worsening sleep or obstructive sleep apnea, causing cardiovascular changes, or leading to EEG changes specifically with tadalafil use.
Monitoring erections that occur during sleep (nocturnal penile tumescence) can help you and your doctor to understand if the erectile dysfunction is due to psychological or physical causes. The nocturnal penile tumescence test is a study to evaluate erections at night. Normally men have three to five erections per eight hours of sleep. The test can be performed at home or in a sleep lab. The most accurate way to perform the test involves a special device that is connected to two rings. The rings are placed around the penis, one at the tip of the penis and the other at the bottom (base) of the penis. The device records how many erections occur, how long they last, and how rigid they are. The test is limited in that it does not assess the ability to penetrate.
Prevention of some of the causes that contribute to the development of erectile dysfunction can decrease the chances of developing the problem. For example, if a person decreases their chances of developing diabetes, heart disease, and hypertension, they will decrease their chances of developing erectile dysfunction. Other things like stopping smoking, eating a healthy diet (heart healthy with adequate vitamin intake), and exercising daily may reduce a person's risk.
When we say it’s a barometer of men’s health, it’s a signal. It’s an indicator that things may be right or not. And so when a man develops an erectile problem– and we’re talking about something that is occurring over time. It’s not something that just occurred overnight. When it occurs overnight, it’s more often than not a psychogenic, an anxiety reaction.
The art of acupuncture has become the new treatment for everything from back pain, depression, and even ED. Impotence could be more of a state of mind, and acupuncture may help. Through this alternative therapy, fine needles are placed in various parts of the body to relieve pain or stress. Although there are many mixed studies for acupuncture and ED, many tend to confirm positive results. A 1999 study found acupuncture improved the quality of erection and even restored sexual activity in 39 percent of participants.

Erectile dysfunction (ED) is one of the most common conditions affecting middle-aged and older men. Nearly every primary care physician, internist and geriatrician will be called upon to manage this condition or to make referrals to urologists, endocrinologists and cardiologists who will assist in the treatment of ED. This article will briefly discuss the diagnosis and management of ED. In addition, emerging concepts in ED management will be discussed, such as the use of testosterone to treat ED, the role of the endothelium in men with ED and treating the partner of the man with ED. Finally, future potential therapies for ED will be discussed.


Experts often treat psychologically based impotence using techniques that decrease anxiety associated with intercourse. The patient's partner can help apply the techniques, which include gradual development of intimacy and stimulation. Such techniques also can help relieve anxiety during treatment of physical impotence. If these simple behavioral methods at home are ineffective, a doctor may refer an individual to a sex counselor.


Intraurethral therapy (Medicated Urethral System for Erections, or MUSE): Alprostadil (PGE1) has been formulated into a small suppository that can be inserted into the urethra (the canal through which urine and semen are excreted). The suppository is preloaded into a small applicator and by placing the applicator into the tip of the penis and compressing the button at the other end of the applicator and wiggling the applicator, the suppository is released into the urethra. Gentle rubbing/massaging of the penis will cause the suppository to dissolve and the medication is absorbed through the urethra and passes into the penis where it stimulates the relaxation of the muscle in the arteries and increases blood flow to the penis. It takes 15 to 30 minutes for this to occur. Success rates in the clinical studies were noted to be about 65%, however lower rates were noted when it started being used in the real world setting. This drug may be effective in men with vascular disease, diabetes, and following prostate surgery. This is a useful alternative for men who do not want to use self-injections or for men in whom oral medications have failed. Few side effects occur. The most common side effect is penile pain, which can vary from minor to uncomfortable. MUSE use has been associated with lowering of the blood pressure and thus it is recommended that the first time using the MUSE be in the physician's office so that you can be monitored. One cannot use lubricants of any type to help with the insertion of the applicator thus to make it easier to insert you should urinate immediately before using the MUSE system as this will lubricate the urethra. A temporary tourniquet is often helpful in allowing the medication to stay in the erectile tissue a little longer and seems to give a somewhat better response.
If conservative treatments for erectile dysfunction are not successful your consultant may recommend penile prosthetic surgery. A penile prosthetic is an implant that allows men with erectile dysfunction to have an erection. Prosthetics may also be used for patients with Peyronie’s disease. There are several types of penile implants. Your consultant will assess your own situation and recommend the implant that meets your needs.

Since endothelial dysfunction, CVD and ED are closely associated in epidemiological studies, the question for clinicians is whether to recommend the man presenting with ED undergo a cardiovascular (CV) evaluation. Clearly, based on numerous studies, ED can be considered at least a ‘marker’ for possible further vascular disease or CVD.15 In their report, Vlachopoulos and coworkers make the point that the man presenting with ED, the clinician, is offered an opportunity to attempt to improve the health of the man by addressing lifestyle modification, and consider further vascular evaluation owing to the clear relationship between endothelial dysfunction, ED and CVD.19
In a prospective study from the Prostate Cancer Prevention Trial database, Thompson et al reported that men presenting with ED had a significantly higher chance of developing a cardiovascular event over a 7-year follow-up period. [55] The hazard ratio was 1.45, which is in the range of risk associated with current smoking or a family history of MI.
If you have ever read the book "The Secret", you understand how powerful the mind can be. Often times Erectile Dysfunction is from stress, psychological or emotional problems. You really have to open your mind and accept that there are other ways to do things. This book has a lot of what I would call yoga, or yoga inspired, techniques. Some of the exercises seemed silly. But that could have been my mind fighting back and resisting change. My wife and I started with the couples massage. Then I tried several of the other techniques over a few days. This past weekend we set up the bedroom to be very romantic. We did the couples massage again. I felt like I was 18. We are going to get some of the suggested herbs this week. There is a technique called "To Be Like a Horse". With a big smile, I will end my review with that.
Erectile dysfunction (ED), or impotence, is the inability to obtain or maintain an erection suitable for intimate activity. While most frequently seen in 50-65% of males aged 65 and older and nearly all men over the age of 70, erectile dysfunction affects up to 39% of 40-year-old men, too; more than 35 million men total in the United States. Left untreated, the physical frustrations of living with erectile dysfunction can quickly turn emotionally stressful as well, with men often reporting relationship and related issues. And that’s why NuMale Medical Center offers the most advanced and effective therapies to treat erectile dysfunction, so you and your partner can experience sex and intimacy both joyfully and confidently.

Oral ED medication is considered highly effective and studies show it works on the majority of men. But no medication works for everyone and ED medication is no exception. Everyone’s reaction to a medication is unique and anything potent enough to help is strong enough to have side effects. If the medication isn’t working, it is important to tell your doctor. Sometimes it is a matter of needing a higher dose. Also, it has been shown that it takes 6 to 8 tries using the medication to experience the best result.
This inflatable penile prosthesis has 3 major components. The 2 cylinders are placed within the corpora cavernosa, a reservoir is placed beneath the rectus muscle, and the pump is placed in the scrotum. When the pump is squeezed, fluid from the reservoir is transferred into the 2 cylinders, producing a firm erection. The deflation mechanism is also located on the pump and differs by manufacturer.
I would think the 25% is just an average. Some men never have a problem with erections. Some healthy men in their 60's never have a problem with their erections -- no Viagra needed at all, thank you. And, no, it is NOT completely associated with age. In fact, many men in their 40's and even younger, are already dealing with ED, especially if they smoke, are obese, don't exercise, or are addicted to porn, among other things. In fact, even men in their 20's and 30's can have these problems.

A duplex ultrasound is a diagnostic technique that uses painless, high frequency sound waves to visualize structures beneath the skin's surface. The principle is similar to the sonar used on submarines. Sound waves are reflected back when they contact relatively dense structures such as fibrous tissue or blood vessel walls. These reflected sound waves can be converted into pictures of the internal structures being studied.

All NOS subtypes produce NO, but each may play a different biologic role in various tissues. nNOS and eNOS are considered constitutive forms because they share biochemical features: They are calcium-dependent, they require calmodulin and reduced nicotinamide adenine dinucleotide phosphate for catalytic activity, and they are competitively inhibited by arginine derivatives. nNOS is involved in the regulation of neurotransmission, and eNOS is involved in the regulation of blood flow.
All NOS subtypes produce NO, but each may play a different biologic role in various tissues. nNOS and eNOS are considered constitutive forms because they share biochemical features: They are calcium-dependent, they require calmodulin and reduced nicotinamide adenine dinucleotide phosphate for catalytic activity, and they are competitively inhibited by arginine derivatives. nNOS is involved in the regulation of neurotransmission, and eNOS is involved in the regulation of blood flow.
Erections are initiated and maintained via integration of afferent inputs in the supra sacral regions of the central nervous system. Regions of the brain cited to have key roles in the integration of signals include the medial amygdala, MPOA, periaqueductal gray matter, paraventricular nucleus (PVN), and ventral tegmentum among others (16). Studies in animal models, particularly in rats, have been paramount in identifying these key areas of signal integration and control. Electrostimulation of the MPOA, PVN and hippocampus lead to erection and lesions in these areas may prevent erection (17). Marson et al. injected labeled pseudorabies virus into rat corpora cavernosa and traced them to neurons in the spinal cord, brain stem and hypothalamus (18). Stimulation of the rat dorsal nerve led to increased firing in the MPOA not found elsewhere (19). Axonal tracing in animals have shows direct projections from the hypothalamus to the lumbosacral autonomic erection centers. Oxytocin and vasopressin have been identified as central neurotransmitters within the hypothalamic nuclei and may have a role in penile erection (17). These signaling studies identifying key areas of erectile response integration may explain how ED is associated with cerebrovascular accident (CVA), Parkinson’s, epilepsy and MS.
When we say it’s a barometer of men’s health, it’s a signal. It’s an indicator that things may be right or not. And so when a man develops an erectile problem– and we’re talking about something that is occurring over time. It’s not something that just occurred overnight. When it occurs overnight, it’s more often than not a psychogenic, an anxiety reaction.
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