These results were confirmed by a double-blind test, which showed that significantly less grafted hair was lost during the rejection period . The use of local minoxidil as a premedication in hair transplant surgery has the advantage of stabilizing hair loss, increasing hair in the anagen phase and reducing postoperative telogen effluvium. Minoxidil should be stopped 2 to 3 days before surgery to minimize skin irritation and reduce the theoretical risk of intraoperative bleeding caused by vasodilation. Androgenetic alopecia is the most common type of hair loss and affects more than 50 million men and 30 million women in the United States. Commonly known as hair loss in men or hair loss in women, androgenetic alopecia runs in families, but can be treated with medication or surgery. Hair consists of follicular units consisting of 3-5 terminal hairs per follicular unit fed by a single pili-drilling muscle, which binds circumference around the primary follicle with variable adhesion to other follicles .
A study showed that frontal male pattern baldness in young men was associated with elevated serum cholesterol levels and higher blood pressure compared to men of comparable age without hair loss . Increased incidence of hypertension and increased aldosterone levels have also been found in women with hair loss in women . Human hair follicles, spread in specific places in the body, seem to have inherited the sensitivity to androgen-dependent puberty growth. Depending on the location of the body, androgens paradoxically have different effects on the follicles of human hair. Androgens stimulate hair growth in some places, such as the beard, axillary and pubic area, and suppress hair growth on the frontal scalp of genetically repelled individuals.
This demonstrates the ability of finasteride to stimulate the conversion of hair follicles into the anagen phase, possibly by reversing the decrease in the anagen phase and increasing the delay phase. A study of scalp biopsies shows that finasteride stimulates an increase in terminal hair and a decrease in the number of villus . Other studies have used hair count and weight as objective outcome measures and have shown that both 生髮失敗 hair weight increases and hair weight increases . Factors that influence hair weight include the number of hairs, the growth rate of the hair and the hair thickness. These findings demonstrate finasteride’s ability to reverse the miniaturization process, creating longer and thicker hair and possibly at a higher growth rate. The first suggested that male pattern baldness can be a risk factor for cardiovascular disease .
Despite the broad expression pattern of the type 1 enzyme, its physiological function is uncertain. Alpha reductase type 2 5 represents approximately 80% of the circulating DHT . Although researchers suspect that different genes play a role in androgenetic alopecia, variations in a single gene, AR, have been confirmed in scientific studies. The AR gene provides instructions for producing a protein called an androgen receptor. With androgen receptors, the body can respond appropriately to dihydrotestosterone and other androgens. Studies suggest that variations in the AR gene lead to increased activity of androgen receptors in capillary follicles.
Other unidentified hormonal, environmental and genetic factors may also be involved. Several studies have shown the effect of local minoxidil in promoting hair growth (). A five-year follow-up with topical minoxidil has demonstrated the persistent effect of minoxidil in long-term use . Minoxidil works as a nonspecific promoter of hair growth, but the slow miniaturization of androgen-induced hair follicles continues despite treatment. Evidence of this is seen in a 120-week double-blind study comparing the weight of cut hair to men treated with 5% minoxidil, 2% minoxidil and placebo, and one untreated group . As expected, the minoxidil groups experienced an increase in hair weight by inducing therapy.
The evidence available so far about the safety of the drug is controversial and needs further evaluation. That is why it is very important to adequately advise patients before treatment. In androgenetic alopecia, the duration of the anagen decreases with each cycle, while the length of the telogen remains constant or continues; This results in a decrease in the ratio of anagen to telogen .
These patients showed a decrease in hair count during the first year with placebo, followed by an improvement in finasteride over the next four years. The improvement is similar to that of the group that received finasteride for five years throughout the study. This shows the relative benefits of early start of finasteride treatment. Some finasteride patients were also crossed for placebo after one year of finasteride treatment.
DHT binds to the androgen receptor with 5 times the greed of testosterone and is more powerful in its ability to cause downstream activation . Two 5 alpha reductase isoenzymes have been characterized, based on their different patterns of optimal pH and tissue expression . Alpha reductase type 1 5 is found immunohistochemical in the sebaceous glands, epidermis, ecrine sweat glands, apocrine sweat glands and hair follicles. In the skin, the activity of type 1 5 alpha reductase is concentrated in the sebaceous glands and is significantly higher in the sebaceous glands of the face and scalp compared to non-acnep sensitive areas. Northern transfer studies reveal an abundance of type 1 mRNA in neonatal foreskin keratinocytes, followed by adult facial epocytes and a stronger expression in the dermal papilla of occipital clothes than of the beard .
Hormones help regulate almost all bodily functions, including hair growth. By getting the right treatment to control any of these thyroid conditions, the hormones remain under control, stop hair loss and your hair can grow. Topical finasteride has been investigated as a possible variation in the supply of medicines. Although 0.05% of the finasteride solution applied to the scalp was well absorbed and caused a 40% reduction in serum DHT, it showed no effect on hair growth. An explanation for this observation is that inhibition of prostate DHT production is an important factor in preventing hair loss in finasterides, that is. In addition to the local 5 alpha reductase block in the hair follics, a significant reduction in the circulating DHT is required .