Health news
Health news top Health news

   Login  |  Register    
Health News Make AMN Your Home PageDiscussion BoardsAdvanced Search ToolMedical RSS/XML News FeedHealth news
  You are here : Health.am > Health Centers > Sexual healthMale Sexual Dysfunction

Endocrinological Causes of Erectile Dysfunction

Male Sexual DysfunctionOct 12, 2007

Testosterone secreted from the Leydig cells of the testes under the influence of luteinizing hormone (LH) is necessary for normal male sexuality and sexual function (Table 4). Medications such as luteinizing hormone-releasing hormone (LHRH) agonists or stilbestrol, which lower circulating testosterone, result in loss of libido and in erectile dysfunction.

Patients who are hypogonadal as a result of pituitary or testicular dysfunction frequently suffer from erectile dysfunction, which responds to treatment with exogenous androgens. More contentious is the suggestion that waning testosterone levels in men of middle age and beyond (Figure 32), the socalled ‘male menopause’, are a frequent cause of erectile dysfunction and, therefore, boosting serum testosterone levels has therapeutic benefits (Table 5).

Vasculogenic Causes of ED
Neurogenic Causes of ED
Endocrinological Causes of ED
Priapism and Postpriapism ED
Psychogenic Causes of ED

However, there is some evidence from experimental animal models that androgens are necessary for the support of intracavernosal smooth muscle function and maintenance of NO synthase levels. Exogenous androgens are certainly capable of enhancing the libido, which is an important component of sexuality.

Dihydrotestosterone (DHT), the potent androgenic metabolite of testosterone produced by the enzyme 5α-reductase, is crucial for the normal development of the male external genitalia, seminal vesicles and prostate, but is not essential for either the libido or erectile function. Compounds such as finasteride, which inhibit the activity of 5α-reductase type II, result in shrinkage of the prostate by 20–30%, but have been reported to cause erectile dysfunction in only around 3–5% of patients.

However, in the 4-year placebo-controlled study of finasteride recently reported by McConnell and colleagues, nearly 14% of patients taking the active drug experienced some form of sexual dysfunction.

Prolactin, which is released from the pituitary gland, acts as an inhibitory factor in male sexual function.

Hyperprolactinemia, either idiopathic or, less commonly, the result of a tumor such as a pituitary prolactinoma (Figure 33), is associated with erectile dysfunction, as is the more common entity of idiopathic hyperprolactinemia. Correction of the raised prolactin levels using bromocriptine may sometimes restore potency in such patients.

-----

Table 3 Neurogenic pathophysiology of organic erectile dysfunction
Diabetes, alcoholism/vitamin deficiencies contribute to somatic/autonomic neuropathy

Demyelinating diseases (e.g. multiple sclerosis) decrease penile sensation

Aging elevates sensory thresholds to vibratory/electrical stimulation

Pelvic/retroperitoneal surgery (e.g. radical prostatectomy) may damage the autonomic nervous system controlling the physiology of penile erection/ejaculation


-----
-----

Table 4 Endocrinological pathophysiology of organic erectile dysfunction
Low testosterone levels associated with decreased libido

Decline in nitric oxide synthase activity in castrated animals reversed by androgen supplementation

Nitric oxide synthase mRNA increases with androgen supplementation

Hypogonadism may be due to primary testicular failure, decreased secretion of gonadotropin releasing hormone (e.g. hyperprolactinemia), or alterations in steroid hormone protein binding (e.g. alcoholism, liver failure)


-----
-----

Table 5 Age-related pathophysiology of organic erectile dysfunction
Cellular senescence alters collagen content in corpora cavernosa/tunica albuginea, leading to venous occlusive dysfunction/decreased neuronal transmission to cavernosal smooth muscle

Aging alters endothelial function, leading to decreased basal nitric oxide release and up-regulation of basal endothelin-1

Reproductive aging in animals impairs neurogenic erectile response: increase in latency period to attain an erection/decrease in maximal intracavernosal pressure; loss of function integrity of endoluminal structures; imbalance in expression of vasoconstricting/vasorelaxing modulators of penile erection/decrease in nitric oxide synthase/increase in endothelin-1 levels

Provided by ArmMed Media

Email this to a friend Bookmark this! Printable Version

RELATED STORIES:


 Comments [ + Post Your Own

Now you're in the public comment zone. What follows is not Armenian Medical Network's stuff; it comes from other people and we don't vouch for it. A reminder: By using this Web site you agree to accept our Terms of Service. Click here to read the Rules of Engagement.

There are no comments for this entry yet. [ + Comment here + ]




We are pleased to let readers post comments about an article. Please increase the credibility of your post by including your full name and email.

All comments are reviewed by our editors before they are posted on the site. Just keep it clean, kids.

Name:

Email:

Location:

URL:

Remember my personal information

Notify me of follow-up comments?

Please enter the word you see in the image below:


   [advanced search]   
Top Erectile Dysfunction Drugs
Viagra | Levitra | Cialis
Interactive Quiz:
1. The most common form of contraception used by couples in the United States is
Pills
Condom
Diaphragm
Intrauterine device (IUD)
Permanent sterilization
Most Searched:
Erectile Dysfunction
Causes of ED
Penile Prosthesis
Male Sexual Dysfunction
Most Viewed:
Premature Ejaculation
Vaginismus
Erectile Disorder
Pedophilia
Transvestism
Premature Ejaculation
Gender Identity Disorder of Adulthood
Paraphilias and Paraphilia-Related Disorders



Health Centers

  Contraception

  Male Infertility

  Erectile Dysfunction

  Male Sexual Dysfunction

  Sexual and Gender
  Identity Disorders


  Sexual Desire Disorders

  Male Erectile Disorder

  Female Sexual Arousal
  Disorder and Female
  Orgasmic Disorder


  Premature Ejaculation and
  Male Orgasmic Disorder


  Sexual Pain Disorders

  Paraphilias and
  Paraphilia-Related Disorders


  Pedophilia

  Transvestism and Gender
  Identity Disorder in Adults


  Gender Identity Disorder in
 Children and Adolescents


» » »


  Sexually Transmitted
  Infections


  Bacterial Infections

   - Neisseria Gonorrhoeae

   - Chlamydia Trachomatis

   - Treponema Pallidum

  Protozoan and
  Fungal Infections


   - Candida Albicans

   - Trichomonas Vaginalis

  Viral Infections

   - Introduction

   - Human Papillomavirus

  Sexually Transmitted
  Disease Syndromes


   - Bacterial Vaginosis

   - Pelvic Inflammatory
   - Disease


   - Epididymitis

   - Proctitis

Health Centers





Diabetes









Health news
  


Health Encyclopedia

Diseases & Conditions

Drugs & Medications

Health Tools

Health Tools



   Health newsletter

  





   Medical Links



   RSS/XML News Feed



   Feedback






Sexual health News, Headlines and Latest Stories on Health.am
Add to My AOL

Add to Google Reader or Homepage




Ovantra: Put the SEX Drive Back into your marriage

hit counter