Physiological function of retinol

Introduction to retinol

Retinol, also known as vitamin A, is the first to be found in vitamins. There are two kinds of vitamin A. There are two kinds of retinol, one is retinol (vitamin A), is the first form of vitamin A (only in animal food); the other is carotene, in vivo changes to vitamin A(can be taken from the plant and animal food intake). The amount of vitamin A is measured in US Pharmocopea, International Units, Retinol Equivalents and other three kinds of substances.

The history of modern discovery of retinol

In 1913, the United States Tewei Si and other four scientists found that cod liver oil can cure dry eye, and from the cod liver oil to extract a yellow viscous liquid. In 1920 the British scientist Manuel was officially named retinol. Internationally regarded retinoids as a necessary factor in nutrition, lack of lead to night blindness.

Physiological function of retinol

1, to maintain normal visual function.

The photoreceptors of the eye are rod cells and cones in the retina. These two kinds of cells are the presence of photosensitive pigments, that is, a sense of light light rhodopsin and a sense of light as violet blue. Rhodopsin and violet blue are composed of opsin and retinal. The retinol released from the liver binds to the retinol binding protein (RBP), binds to the prealbumin in plasma and is transported to the retina to participate in the photochemical reaction of the retina. If the retinol is sufficient, the rhodopsin is regenerated Fast and complete, so the dark to restore the recovery time is short; if the lack of retinol, then rhodopsin slow regeneration is not complete, so the dark to restore the recovery time is prolonged, can produce severe night blindness (NightBlindness).

2, to maintain the health of epithelial cells and promote the synthesis of immunoglobulins.

Retinol can be involved in the synthesis of glycoproteins, which is important for the normal formation, development and maintenance of epithelium. When the lack of or lack of retinol, can lead to abnormal synthesis of glycoprotein intermediates, low molecular weight polysaccharide – fat accumulation, causing epithelial basal layer hyperplasia thickening, cell division to speed up the increase in tension fibril synthesis, surface layer of cells Flattened, irregular, dry and other changes. Excessive intake of retinol, the resistance to epithelial infection does not increase with the dose.

Immunoglobulin is a glycoprotein, retinol can promote the synthesis of the protein, the immune function of the body has an important impact, the lack of cellular immunity showed a decline.

3, to maintain the normal growth and development of bones.

Retinol promotes protein biosynthesis and osteoblast differentiation. When it is lacking, the balance between osteoblasts and osteoclasts is destroyed, or osteoblast activity is increased, or bone formation is not absorbed. Pregnant women if the lack of retinol will directly affect the fetal development, or even death.

4, to promote growth and reproduction.

Retinol contributes to cell proliferation and growth. When animals lack retinol, there is a significant growth retardation. The lack of retinol also causes a decrease in the activity of the enzyme required to catalyze the formation of progesterone progesterone, which reduces the production of steroids in the adrenal gland, gonad and placenta, and may be the cause of reproductive function.

5, inhibition of tumor growth.

In recent years found that retinoids have delayed or prevent precancerous lesions, to prevent the role of chemical carcinogens, especially for epithelial tissue tumors, clinically as adjuvant therapy has achieved good results. Β-carotene has antioxidant activity, in recent years a large number of reports, the body is an effective antioxidant to capture reactive oxygen species, to prevent lipid peroxidation, prevention of cardiovascular disease, cancer, and anti-aging are important significance.

6, nutritional supplements

Retinol in cosmetics as a nutritional ingredient additives, to prevent the skin rough, promote normal growth and development, can be used in cream emulsion.

Pharmacological effects of retinol

Retinol can easily be absorbed after oral administration, mainly in the liver. Almost all in the body is metabolized, β-carotene is retinol precursors, in the animal intestinal mucosa can be converted into active retinol. Mainly through the urine, fecal excretion, and only a small amount of milk excretion.

Retinol can treat dry eye, corneal softening, dry skin and night blindness. In addition, the hot, frostbite and ulcers also have effect.

Retinol can increase the number of spleen PFCs in sheep with red blood cells or protein, and enhance the production of antibodies caused by non-T cell-dependent antigens. It can also enhance human peripheral blood lymphocytes on PHA response and NK cell activity, improve macrophage activity, stimulate T cell proliferation and IL 2 production.

The lack of retinol

Suffering from retinol deficiency disease often malnutrition, chronic diarrhea, chronic dysentery, measles long after the mouth, photophobia, unknown blink of an eye and other complications. Older children will be dry skin, hair follicle keratosis and other changes. Early and atypical cases, mild changes in the eye, especially in infants and young children easily overlooked. If the food in the lack of retinoids or have absorption disorders, can occur within a few weeks of symptoms. Infants suffering from congenital biliary obstruction, hepatitis syndrome, if retinol complicated by pneumonia can occur in a short time of eye dryness.

Clinical manifestations:

1, eye symptoms: the emergence of earlier symptoms, but the symptoms of older children often appear in other symptoms.

2, the skin performance: the skin is easy to dry, hyperplasia, scaling off.

3, other performance:

Purulent urine: refers to the urine contains a large number of pus cells that white blood cells, clinically refers to the purulent cells is degeneration of white blood cells, so the disease, also known as white blood cells. Patients usually have pyelonephritis fever, nausea, vomiting, systemic pain and other systemic infection symptoms of poisoning, local symptoms have varying degrees of low back pain, bladder irritation, stones and other symptoms.

Respiratory secondary infection: usually secondary to infection by bacteria, likely to cause decreased immune function, respiratory and urinary tract epithelial proliferation and keratosis.

Taste loss: tongue buds due to epithelial keratosis taste loss, affect appetite, and some children may have vomiting.

Other: physical retardation. Poor blood cell formation.