What is male reproductive endocrinology?
Male reproductive endocrinology is a sexual development and hormonal function that depends on a complex feedback loop consisting of a hypothalamus-pituitary-testis modulated by the central nervous system. Male sexual dysfunction is second only to hypogonadism, neurovascular disorders, drugs, or other disorders.
Despite the growing interest in men’s health and the growing number of clinics dedicated to male reproductive health, not all providers trust the latest science or use evidence-based methods. We have developed our clinical practice guide on testosterone treatment and other science-based resources to ensure that men with reproductive health problems can receive the best medical diagnosis and care.
Testosterone and DHT have metabolic and other effects, including
- Stimulating protein anabolism (increasing muscle mass and bone density)
- Stimulating renal erythropoietin production (increasing red blood cell mass)
- Stimulating bone marrow stem cells (modulating the immune system)
- Causing cutaneous effects (ie, sebum production, hair growth)
- Causing neural effects (ie, affecting cognition, increasing libido, and possibly aggression)
Testosterone also undergoes conversion to estradiol by the enzyme, aromatase; estradiol mediates most of testosterone’s action on organs such as bones and the brain. Testosterone, DHT, and estradiol provide negative feedback on the hypothalamic-pituitary axis. In males, estradiol is the main inhibitor of LH production, whereas both estradiol and inhibin B, a peptide produced by Sertoli cells of the testes, inhibit the production of FSH.
In the presence of testosterone, FSH stimulates the Sertoli cells and induces spermatogenesis. In spermatogenesis, each germinal cell (spermatogonium), located adjacent to the Sertoli cells, undergoes differentiation into 16 primary spermatocytes, each of which generates 4 spermatids. Each spermatid matures into a spermatozoon. Spermatogenesis takes 72 to 74 days and yields about 100 million new spermatozoa each day.
Upon maturation, spermatozoa are released into the rete testis, where they migrate to the epididymis and eventually to the vas deferens. Migration requires an additional 14 days. During ejaculation, spermatozoa are mixed with secretions from the seminal vesicles, prostate, and bulbourethral glands.
How male reproductive endocrinology is assessed?
If you and your partner are unable to conceive after a year of trying, you should speak with your primary care physician, who can refer you to a fertility specialist. A urologist or reproductive endocrinologist can help diagnose and treat male infertility.
It starts with your doctor’s medical history. Your childhood growth and development, and you may have questions about past infections and surgeries, sexually transmitted diseases, testicular damage, and exposure to harmful chemicals or drugs.
Your doctor will perform a physical exam to check for low testosterone levels or other conditions that affect fertility (such as small or missing testicles). You will have a sperm test (often more than one) to see the size, movement, and shape of the sperm. Blood tests look for a hormone deficiency.
Also, your doctor may perform a scrotal or transrectal ultrasound. This imaging test looks for varicose veins around the testicles, tumors, or obstruction in the vas deferens. Your partner must have a complete medical history and evaluation at the same time. It gives you a complete picture of your potential as a couple with children.
Causes of male reproductive endocrinology
In about 30 to 40 percent of cases, the problem is in the testicles, the glands that make sperm, and testosterone (the main male sex hormone). Cancer treatments such as damage to the tonsils, infections such as tonsils, radiation or chemotherapy, trauma, or surgery.
Heat affects sperm production. Heat loss occurs when one or both testicles do not descend from the abdomen (where they were before birth) into the scrotum (usually the sac of skin that contains the testicles). Most men dilate the veins around the testicles (called a varicocele), which also raises the temperature in the testicles. If they are very large, a varicocele can lead to less sperm production.
Some inherited (genetic) diseases may or may not cause motility or reduced sperm production. In 10 to 20 percent of cases, the problem is the obstruction in the passage of sperm from the testicles to the penis through tubes called the vas deferens. It can be caused by infection scars, vasectomy (surgery to cut the vas deferens and prevent sperm), or cystic fibrosis (genetic disease). In addition to the penis, the backward movement of sperm into the bladder can also cause infertility.
In rare cases, infertility is caused by a hormonal deficiency. The testes produce luteinizing hormone (LH) and follicle-stimulating hormone (FSH) testosterone and sperm. The pituitary gland in the brain produces these hormones. Any condition that lowers LH and FSH levels, such as a pituitary tumor, can lead to low or low sperm production and low levels of testosterone in the blood.
In 30 to 40 percent of men with infertility, the cause is not found. But, these men usually have abnormal sperm (for example, sperm that are slow-moving, abnormally shaped, or in small numbers). Other problems include reduced sperm production and fertility. These include chronic (chronic) illnesses, total health, late payments, certain prescription drugs, and medications.
Treatment for male reproductive endocrinology treated?
Treatment of male reproductive endocrinology depends on the cause.
Surgery: Obstruction of the sperm transport system can be corrected surgically. Vasectomy can be reversed by surgery in 85% of cases, but most men remain infertile even after the barrier is resolved (other types of barriers are difficult to treat due to past infections). If veins are large and repaired before chronic damage, varicocele repair is likely to restore fertility. Surgery can also repair the varicocele, but it may not restore fertility.
Hormonal therapy: If the cause is due to low testosterone levels, treatment with injections of hormones (LH and FSH) is usually successful. However, hormone therapy can take a year or more to produce enough sperm and regain fertility.
Assisted reproductive technologies: Other options for a couple to achieve pregnancy are assisted reproductive techniques. These treatments involve injecting the collected sperm into the uterus, injecting the sperm with the egg outside the body (in vitro fertilization or IVF), or injecting a sperm into the egg (intracytoplasmic sperm injection or ICSI).
To improve your chances of successful treatment, it is helpful to maintain a healthy lifestyle exercise often, eat a healthy diet, and do not smoke or use recreational drugs. Also, continue treatment for any chronic illness.