Uric acid is formed in humans during breakdown of purines. Purines are naturally produced in the body, and found in some foods and beverages. Uric acid is excreted with urine. Excess uric acid forms crystals in bone joints and is linked to gout, kidney stones and type 2 diabetes.
Discovery of Uric Acid
Uric acid is first isolated from kidney stones in 1776 by Swedish chemist Carl Wilhelm Scheele. In 1797 another Swedish chemist, William Cruickshank, discovers that crystals form in concentrated urine treated with nitric acid.
The crystals are acidic and can detonate if set on fire. This volatile concoction is urea nitrate. In 1882, Ukrainian chemist Ivan Horbaczewski first synthesizes uric acid by melting urea with glycine.
How Uric Acid is Made in the Body
Uric acid is synthesized primarily in the liver through purine metabolism. The catabolism of purine nucleotides adenine and guanine. Nucleotides form the basic structural unit of nucleic acids such as DNA.
This causes production of hypoxanthine and xanthine, which further convert into uric acid through the action of the enzyme xanthine oxidase. This production occurs continuously, depending on dietary intake and cellular turnover.
Other Components of Urine
Urine consists of various components besides uric acid, which include:
Water: Comprising approximately 95% of urine, water acts as a solvent.
Urea: A major waste product derived from protein metabolism.
Creatinine: A waste product created from muscle metabolism.
Electrolytes: Such as sodium, potassium, chloride, calcium, and magnesium.
Hormones: Various hormones are also excreted through urine.
Metabolites: Including compounds derived from the breakdown of drugs and food.
Uric Acid Bacteria
Some bacteria can metabolize uric acid. These are often called uric acid bacteria or UAB. They use specialized pathways to break down uric acid for energy, converting it into ammonia and carbon dioxide.
Species of Bacillus and Pseudomonas have been identified as uric acid-utilizing bacteria, important to such tasks as breaking down organic matter. Some bacteria produce uricase, an enzyme to convert uric acid into allantoin, which is more soluble.
The notorious Escherichia coli bacteria insidiously produces uric acid through its activities. In contrast, Lactobacillus gasseri PA-3 reduces serum uric acid levels in patients with marginal hyperuricemia or excess uric acid.
Uric Acid in Nature
In nature, uric acid serves multiple vital functions, especially as a waste product in birds and reptiles. Its key roles include:
Nutrient Cycling: Uric acid returns nitrogen to the soil, enhancing plant growth and productivity.
Energy Source: Soil bacteria can use uric acid as an energy source, supporting microbial populations in various ecosystems.
Water Conservation: Birds and reptiles in dry habitats excrete uric acid as a paste to conserve water.
Historical Uses
Historically, uric acid is studied primarily in the context of medicine. Ancient civilizations use animal urine to diagnose various illnesses due to the presence of uric acid crystals. In some practices, it's used in folk medicine.
In the ancient world, people observe its presence in waste and sometimes use urine for its cleaning properties. In traditional medicine, practitioners analyze urine to provide insights into health, using a urine analysis chart showing different colors or sediments of urine.
Modern Uses
In modern times, uric acid is used in clinical settings to evaluate kidney function and diagnose conditions like gout and kidney stones. Research continues into its role as an antioxidant at certain levels in the body, as well as its effects on cardiovascular health.
Facts About Uric Acid
Normal Levels: The normal range for uric acid in the blood is typically between 3.5 to 7.2 mg/dL for men and 2.6 to 6.0 mg/dL for women.
Gout: Excess levels of uric acid can lead to gout, characterized by painful inflammation in the joints, affecting nearly 8 million adults in the US.
Dialysis: Individuals with kidney failure often exhibit elevated levels of uric acid due to reduced excretion.
Diet: Foods rich in purines, such as red meat and seafood, can raise uric acid levels.
Lowering Levels: Hydration, dietary modifications, and medications can help manage high uric acid levels. Diets rich in Vitamin C, such as citrus fruits, can help lower uric acid levels.
Scientific Properties
Uric acid has the chemical formula C₅H₄N₄O₃. As a weak acid, it has a pKa value of approximately 5.4. When it precipitates, it can form monosodium urate crystals, which contribute to health issues like gout.
Uric acid's properties include:
Solubility: It has limited solubility in water, which can cause it to crystallize in joints or kidneys if levels become too high.
Chemical Structure: With the formula C₅H₄N₄O₃, uric acid consists of a bicyclic structure containing four nitrogen atoms.
Antioxidant Ability: Uric acid is an antioxidant, helping neutralize free radicals and possibly offering protection against oxidative stress.
Non-Fiction Books:
Fiction Books:
READ: Lora Ley Adventures - Germanic Mythology Fiction Series
READ: Reiker For Hire - Victorian Detective Murder Mysteries