More than 95% of male alopecia is androgenic alopecia, also known as male alopecia; The main performance is that the hairline of the temples and foreheads moves backward, accompanied by thinning of the hair at the top, which eventually becomes a piece with the degree, but rarely affects the temples and occipitals. We can refer to Hamilton Norwood Scale to evaluate the degree of male hair loss.
We have spent a lot of research energy on such a chronic disease that affects all mankind. Now we have noticed that androgenetic alopecia is closely related to a 5α reductase. Hair follicles are rooted in the dermis of the scalp. When the blood vessels nearby relax and bring enough oxygen, dermal papillae will rapidly divide into a large number of dead cells. These dead cells pile up like mountains, eventually wearing the body surface, that is, hair; For thousands of years, the vigorous metabolism of dermal papilla needs the support of insulin-like growth factor, which is responsible for promoting the nutrient accumulation and anabolism of cells, but the same amount of androgen acts on hair follicles and dermal papilla.
Insulin-like growth factor will decay, dermal papilla will divide slowly, hair will grow thinner and thinner, and finally the broken new hair will not grow, which will eventually show alopecia; And those excessive androgens are not the result of active gonads; There is always a particularly active 5α reductase in the hair follicles of men with alopecia. Testosterone can be reduced to dihydrotestosterone, and the ability of dihydrotestosterone to bind androgen receptor is ten to dozens times that of testosterone, which is the chief culprit of hormonal alopecia.
The corresponding dihydrotestosterone plays a dual role in hair growth regulation, which plays the above-mentioned destructive role in hair follicles above the temple, but in other whole body hair. Instead, it activates insulin-like growth factor, so patients with androgenetic alopecia. Body hair, beard and even nose hair are normal, even extra thick.
With the rapid increase of testosterone synthesis in men after the age of 20, it decreases at a slow rate. Boys after the age of 25 almost invariably show different degrees of hair loss symptoms, but the differences between different individuals affected by genes are quite huge; The most well-known case is that the British royal man, the husband of Queen Elizabeth II, Prince Philip, is bald and Prince Charles is bald; Princess Diana's father, Earl Spencer, also has no hair, so both Prince William and Prince Harry thanked the Mediterranean in their thirties, which makes people worry whether the third heir will suffer the same fate in adulthood.
Therefore, the current treatment measures for androgenic alopecia focus on how to eliminate the negative effects of dihydrotestosterone. For example, finasteride, which is similar in structure to androgen, can block the catalytic function of 5α reductase, effectively relieve the symptoms of alopecia, and treat prostate hypertrophy caused by excessive dihydrotestosterone, but it may lead to sexual dysfunction during medication. Another common drug, such as minoxidil, is a potassium channel-opening drug, which can dilate the capillaries of hair follicles for external use, bring sufficient nutrition to the papilla and effectively relieve the symptoms of alopecia. It can even make other parts grow thick black hair, but it may also bring redness, itching and even dizziness and chest pain.