The role of the endothelium in erectile function became clearer with the observation that the phosphodiesterase type 5 (PDE5) inhibitor, sildenafil, enhanced erectile function. Erection occurs with the release of nitric oxide (NO) from the vascular endothelial cells.17 The reduction in endothelial cell production of NO results in the negative impact on the smooth muscles in the corporal bodies and results in less relaxation of the smooth muscle cells with decrease in blood supply and resulting ED. A similar phenomenon is well known to impact the coronary arterial system resulting in CVD.
Causes of impotence are many and include heart disease, high cholesterol, high blood pressure, obesity, metabolic syndrome, Parkinson's disease, Peyronie's disease, substance abuse, sleep disorders, BPH treatments, relationship problems, blood vessel diseases (such as peripheral vascular disease and others), systemic disease, hormonal imbalance, and medications (such as blood pressure and heart medications).
Tests such as the bulbocavernosus reflex test are used to determine if there is sufficient nerve sensation in the penis. The physician squeezes the glans (head) of the penis, which immediately causes the anus to contract if nerve function is normal. A physician measures the latency between squeeze and contraction by observing the anal sphincter or by feeling it with a gloved finger inserted past the anus.

Cialis is available in three strengths: 5mg, 10 mg, and 20 mg. Cialis can work in 30 minutes, but peak results usually take longer. Cialis has the advantage of a much longer period (24-36 hours) during which sexual ability is increased. The newest formulation of Cialis is the 5 mg dosage for daily use. The major advantage of daily dosing is that it allows for spontaneous sexual activity.

Another study compared the response of surgically and medically castrated rabbits to vardenafil with that of control rabbits. [22] Castrated rabbits did not respond to vardenafil, whereas noncastrated rabbits did respond appropriately. This result suggests that a minimum amount of testosterone is necessary for PDE5 inhibitors to produce an erection.

Hormone deficiency or hypogonadism, whether primary or secondary, has been thought to impact erectile function. Approximately a third of men in the European Male Aging Study demonstrated low testosterone, suggesting that hypogonadism is overrepresented among men with ED.11 Hormone deficiency, however, is less frequently the cause of ED than diabetes or vascular disease. Many entities with a strong relationship to ED also diminish bioavailable testosterone, including obesity, diabetes, and opioid use. Other hormones involved in testosterone metabolism or availability, like thyroid stimulating hormone and gonadotropins, also may impact erectile quality, presumably through regulating bioavailable testosterone. Understanding the relationship between testosterone and ED has been impaired by a lack of standardized measurement of this hormone and the cyclic nature of its release and consumption.
In the short term, alcohol relaxes muscles in the penis, letting blood to flow in (which is a good thing). However, alcohol also prevents other blood vessels from closing and trapping all the extra blood. Erections depend on trapping increased blood flow in the erectile tissue of the penis. If you don’t trap that extra blood, you don’t get an erection. In the long run, excessive alcohol consumption can cause liver scarring, high blood pressure, and can damage your blood vessels resulting in erectile dysfunction.
MSA is a neurodegenerative disease of undetermined etiology, where ED is an early prominent sign occurring in 40% of men at the time of diagnosis (46,47). ED occurs in the majority of patients and the exact cause of it is unknown (48). Like PD, MSA likely affects the dopaminergic pathways within the brain essential for arousal (49). Orthostatic hypotension (OH) as a causal factor has been refuted by evidence that sildenafil can overcome reduced filling pressures, and the ED usually precedes the development of OH (46,49,50). Similar to other neurologic disorders that lead to ED, other disease related factors such as psychosocial stress, the burden of chronic illness, changed appearance, fatigue, decreased fine motor movement of fingers, immobility and diminished self-esteem due to loss of independence may contribute as well (51).
SD in MS can be classified into three categories. Primary SD is due directly due to MS-related neurological deficits, secondary SD is related to physical impairments and symptoms or drugs used for MS treatment, and tertiary SD is due to the psychological, social and cultural problems attributed to MS (38). These classifications are important, and underscore the importance of addressing all the issues leading to SD not just the neurologic impairment.
Although not proven, it is likely that erectile dysfunction can be prevented by good general health, paying particular attention to body weight, exercise, and cigarette smoking. For example, heart disease and diabetes are problems that can cause erectile dysfunction, and both are preventable through lifestyle changes such as sensible eating and regular exercise. Furthermore, early diagnosis and treatment of associated conditions like diabetes, hypertension and high cholesterol may prevent or delay erectile dysfunction, or stop the erectile dysfunction from getting more serious.
Acupuncture may help treat psychological ED, though studies are limited and inconclusive. You’ll likely need several appointments before you begin to notice any improvements. When choosing an acupuncturist, look for a certified practitioner who uses disposable needles and follows U.S. Food and Drug Administration guidelines for needle disposal and sterilization.

Performance anxiety can be another cause of impotence. If a person wasn’t able to achieve an erection in the past, he may fear he won’t be able to achieve an erection in the future. A person may also find he can’t achieve an erection with a certain partner. Someone with ED related to performance anxiety may be able to have full erections when masturbating or when sleeping, yet he isn’t able to maintain an erection during intercourse.
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.
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.

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.

Positron emission tomorgraphy (PET), and functional magnetic resonance imaging (fMRI) have led to a greater understanding to which center are activated during arousal. These imaging studies measure increases in cerebral blood flow or changes in cerebral activity on a real-time basis. Studies are performed when male subject are aroused by visual cues (usually sexual explicit photos or videos) and compared to images obtained during exposure to sexually neutral cues differences can be measured. Several studies have identified that the inferior frontal lobes, inferior temporal lobes and insular gyrus, and occipital lobes are involved with processing arousal cues, although each are likely to process different stimuli (20-23).
In a 2005 study, three months of twice-daily sets of kegel exercises combined with biofeedback and advice on lifestyle changes, such as quitting smoking, losing weight, and limiting alcohol, worked far better than just giving the participants advice. “Wearing tight pants will affect impotence along with some other medical conditions like diabetes and heart disease,” which can also affect a man’s degree of impotence, Dr. Jennifer Burns, specializing in family practice with an emphasis on gastrointestinal health at the BienEtre Center, told Medical Daily.

The pathogenesis of organic ED is related to dysfunction of the endothelium. Endothelial cells can become injured through a variety of mechanisms, most of which cause oxidative stress on the tissues. Many of these causes of oxidative stress are related to lifestyle issues which lead to hypertension, diabetes and dyslipidaemia (figure 1). Endothelial cell dysfunction results in reduction of endothelium-dependent vasorelaxation as well as increased adhesion of leukocytes to the endothelium. Endothelial cell injury then leads to a variety of sequelae, including ED, other types of vasoconstriction, atherosclerosis and thrombus formation.18
Viagra is available in three strengths: 25 mg, 50 mg, and 100 mg. Viagra works best if taken on an empty stomach about 30-45 minutes before sexual activity. Optimal results may not be realized until the medication has been tried six to eight times. Viagra may be used cautiously with alpha-blocker medications as long as sufficient time has passed between their dosing.
The physical side effects of chemotherapy are usually temporary and resolve within one to two weeks after stopping the chemotherapy. However, chemotherapy agents, such as Ciplatin or Vincristine, may interfere with the nerves that control erection leading to possible impotence. Make sure you discuss potential side effects of cancer chemotherapy with your doctor or healthcare provider.
Think of erectile dysfunction as your body’s “check engine light.” The blood vessels in the penis are smaller than other parts of the body, so underlying conditions like blocked arteries, heart disease, or high blood pressure usually show up as ED before something more serious like a heart attack or stroke. ED is your body’s way of saying, “Something is wrong.” And the list of things that cause erectile dysfunction can include:

Aging, liver and kidney problems, and concurrent use of certain medications (such as erythromycin [an antibiotic] and protease inhibitors for HIV) slows the metabolism (breakdown) of sildenafil. Slowed breakdown allows sildenafil to accumulate in the body and potentially may increase the risk of side effects. Therefore, in men over 65 years of age, in men with significant kidney and liver disease, and in men who also are taking medications called protease inhibitors, the doctor will initiate sildenafil at a lower dose (25 mg) to avoid accumulation of sildenafil in the body. A protease inhibitor ritonavir (Norvir) is especially potent in increasing the accumulation of sildenafil, thus men who are taking Norvir should not take sildenafil doses higher than 25 mg and at a frequency of no greater than once in 48 hours. Other medications that may affect the level of sildenafil include erythromycin and ketoconazole.
Surgery: If neither drugs nor the vacuum pump works, your doctor may suggest surgery. With surgery, the doctor can place a device in your penis that will cause enough hardness for intercourse. In a few cases, infections may develop after the operation, and the doctor may have to remove the device. Another operation that may help you is rebuilding the blood vessels in the penis to increase blood flow into the penis or decrease blood flow out of the penis. These procedures can help you to get and maintain an erection.
Sildenafil (Viagra) was the first oral phosphodiesterase type 5 (PDE5) inhibitor approved by the FDA in the United States for the treatment of erectile dysfunction (it is not approved for women). Sildenafil inhibits PDE5, which is an enzyme that destroys cGMP. By inhibiting the destruction of cGMP by PDE5, sildenafil allows cGMP to accumulate. The cGMP in turn prolongs relaxation of the smooth muscle of the corpora cavernosa. Relaxation of the corpora cavernosa smooth muscle allows blood to flow into the penis resulting in increased engorgement of the penis. In short, sildenafil increases blood flow into the penis and decreases blood flow out of the penis.
Vascular damage may result from radiation therapy to the pelvis and prostate in the treatment of prostate cancer. [36] Both the blood vessels and the nerves to the penis may be affected. Radiation damage to the crura of the penis, which are highly susceptible to radiation damage, can induce ED. Data indicate that 50% of men undergoing radiation therapy lose erectile function within 5 years after completing therapy; fortunately, some respond to one of the PDE5 inhibitors.
Research has even found possible links to frequent ejaculation and a lower risk of prostate cancer. In one study of 32,000 men published in 2016 in the journal European Urology, for example, men who ejaculated at least 21 times per month while in their 20s were less likely to be diagnosed with prostate cancer than those who ejaculated four to seven times per month. And men who ejaculated more often in their 40s were 22 percent less likely to get a prostate cancer diagnosis.
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.
Because the burning side effect is triggered by alprostadil, the formulations with the least alprostadil — tri-mix and certain versions of bi-mix — could work for men who experience burning with the single-drug formula. But some men might choose alprostadil alone because the multi-drug cocktails can cost more and must be dispensed by a compounding pharmacy — one that is authorized to mix medications on site — which could mean the added hassle of a long drive to pick up the drug.
The laboratory results should be discussed with the patient and, if possible, with his sexual partner. This educational process allows a review of the basic aspects of the anatomy and physiology of the sexual response and an explanation of the possible etiology and associated risk factors (eg, smoking and the use of various medications). Treatment options and their benefits and risks should be discussed. This type of dialogue allows the patient and physician to cooperate in developing an optimal management strategy.
Capogrosso, P., Colicchia, M., Ventimiglia, E., Castagna, G., Clementi, M. C., Suardi, N., ... Salonia, A. (2013, July). One patient out of four with newly diagnosed erectile dysfunction is a young man — worrisome picture from the everyday clinical practice. The journal of sexual medicine. 10(7), 1833–1841. Retrieved from https://onlinelibrary.wiley.com/doi/full/10.1111/jsm.12179
• Blood Vessels: Diabetes damages blood vessels, especially the smallest blood vessels such as those in the penis. Diabetes can also cause heart disease and other circulatory problems. Proper blood flow is absolutely crucial to achieving erection. “Erection is a hydraulic phenomenon that occurs involuntarily,” says Arturo Rolla, MD, of Harvard University School of Medicine. “Nobody can will an erection!” Anything that limits or impairs blood flow can interfere with the ability to achieve an erection, no matter how strong one’s sexual desire.

Patients with both ED and cardiovascular disease who receive treatment with an oral PDE5 inhibitor require education regarding what to do if anginal episodes develop while the drug is in their system. Such education includes stressing the importance of alerting emergency care providers to the presence of the drug so that nitrate treatment is avoided.
Both ED and low testosterone (hypogonadism) increase with age. The incidence of the latter is 40% in men aged 45 years and older. [15] Testosterone is known to be important in mood, cognition, vitality, bone health, and muscle and fat composition. It also plays a key role in sexual dysfunction (eg, low libido, poor erection quality, ejaculatory or orgasmic dysfunction, reduced spontaneous erections, or reduced sexual activity). [16]
Do erectile dysfunction exercises help? Many people have erectile dysfunction (ED), but it is often possible to reverse this with exercises to strengthen muscles in the area. These include pelvic floor exercises. ED can often be due to lifestyle factors including obesity and low physical activity levels. Learn more about exercises for ED here. Read now
The lab testing obtained for the evaluation of erectile dysfunction may vary with the information obtained on the health history, physical examination, and recent lab testing. A testosterone level is not necessary in all men; however, a physician will order labs to determine a patient's testosterone level if other signs and symptoms of hypogonadism (low testosterone) such as decreased libido, loss of body hair, muscle loss, breast enlargement, osteoporosis, infertility, and decreased penile/testicular size are present.
The physical examination can reveal clues for physical causes of erectile dysfunction. A doctor will perform an assessment of BMI and waist circumference to evaluate for abdominal obesity. A genital examination is part of the evaluation of erectile dysfunction. The examination will focus on the penis and testes. The doctor will ask you about penile curvature and will examine the penis to see if there are any plaques (hard areas) palpable. The doctor will examine the testes to make sure they are in the proper location in the scrotum and are normal in size. Small testicles, lack of facial hair, and enlarged breasts (gynecomastia) can point to hormonal problems such as hypogonadism with low testosterone levels. A health care provider may check pulses in your groin and feet to determine if there is a suggestion of hardening of the arteries that could also affect the arteries to the penis.
Choosing the treatment that is best for you comes down to preference and efficacy. Montague cites a study that surveyed three groups of men, all of whom were successfully using an ED treatment. One group was on oral medications, one was using injections and a third had surgically implanted pumps. The most satisfied users were those with the implanted prostheses.
The penis contains three cylinders, the two corpora cavernosa, which are on the top of the penis (see figure 1 below). These two cylinders are involved in erections. The third cylinder contains the urethra, the tube that the urine and ejaculate passes through, runs along the underside of the penis. The corpus spongiosum surrounds the urethra. Spongy tissue that has muscles, fibrous tissues, veins, and arteries within it makes up the corpora cavernosa. The inside of the corpora cavernosa is like a sponge, with potential spaces that can fill with blood and distend (known as sinusoids). A layer of tissue that is like Saran Wrap, called the tunica albuginea, surrounds the corpora. Veins located just under the tunica albuginea drain blood out of the penis.
ED usually has something physical behind it, particularly in older men. But psychological factors can be a factor in many cases of ED. Experts say stress, depression, poor self-esteem, and performance anxiety can short-circuit the process that leads to an erection. These factors can also make the problem worse in men whose ED stems from something physical.
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