Male hormone

• Male reproductive tract functions include the testis, seminiferous tubules for sperm production and steroid production, the epididymis for sperm collection and maturation, the vas deferens for transport and storage, accessory glands for contributions to seminal fluid, and the urethra for transport.
• Male hormones include androgens such as testosterone and dihydrotestosterone (DHT), estrogens and progesterone which are important in the regulation of male reproduction.
• Androgens are defined as compounds that interact with the androgen receptor (AR), both natural (e.g. testosterone) and synthetic (e.g. nandrolone).
• All the major cell populations in the testis, epididymis and accessory glands express AR.
• The various cell types require androgen-AR binding to fulfil their respective roles in sperm production, transport and activation.
• Hormone action needs receptors in target tissues.
• The hormonal regulation of gonadal hormone production (HPG axis) is the regulatory axis for the production of sex steroid in males and females with slight differences.
• In males, LH and FSH act distally on the testis.
• DHT and testosterone will act on the hypothalamus (reduce GnRH) and pituitary (reduce LH & FSH) in the regulation of gonadal hormone production.
• FSH works on sertoli cell and LH works on Leydig cell in the regulation of spermatogenesis.
• Spermatogonium divide and mature as they pass through the sertoli cells during spermatogenesis.
• As sperm get closer to the lumen, they get more mature.
• The ability to swim is initially acquired in the epididymis (DHT-dependent).
• Testosterone + progestin found to give more effective suppression of sperm production, allowing reduction of testosterone dose.
• Effective and reversible suppression of testicular function can be achieved with Testosterone + progestin.
• Symptoms of prostatic cancer include urgent and frequent urination, nocturnal enuresis, difficulty starting or emptying bladder, urine flow weak, interrupted or difficult to control, and back or pelvic pain.
• Prostate Specific Antigen (PSA) is a blood test to check for prostate cancer.
• Hormonal contraception for men aims to inhibit sperm production to a level sufficient to inhibit fertility.
• Exogenous Testosterone reduces LH & FSH, but needs high doses as it is difficult to completely inhibit sperm production.
• Further activation in the female tract is called capacitation.
• Normal Semen parameters (Normozoospermia): Volume of ejaculate = 1.5 - 5.0 ml, Sperm count = 40 - 250 million/ml, Sperm motility = 1 hour after ejaculation, 70%, Leukocyte count = 0 - 2000/ ml, pH = 7.2 – 7.8, Fructose concentration = 150 - 600 mg/100ml.
• With 6 successive menstrual cycles and actively trying to become pregnant, there may be a problem with fertilisation.
• Major causes of male infertility are often linked to problems with production or transport of sperm.
• With high sperm count, the probability of becoming pregnant is 25 - 30% of menstrual cycles due to the quality of the sperm.
• At the point of release into the lumen of the seminiferous tubule, sperm are not yet motile.
• Male infertility and subfertility affect 5 - 7% of men, with 30% of cases due to infertility problems solely in the male.
• Management of male infertility includes lifestyle modifications, treatment of infections, and assisted reproductive technology (ART).
• Management of prostatic cancer is based on reducing testosterone production or actions, including anti-androgen therapy, LH blockade, and 5 a-reductase inhibitors.
• Erection is caused by engorgement of erectile tissue, corpus cavernosa & corpus spongiosum with blood, arterioles dilated (parasympathetic nervous system activity).
• Prostatic cancer is the second leading cause of death in men, with an overall lifetime risk of 1 in 6 and risk factors including age, ethnicity, and family history.
• Emission & ejaculation are controlled by the sympathetic nervous system.
• Sperm production is suppressed to <3 million/mL, allowing a reduction of the dose of testosterone that would be used.
• Exogenous testosterone can reduce LH & FSH, leading to reduced fertility.