Bile Acids

steroid monocarboxylic acids, derivatives of cholanic acid that are formed in the liver of man and animals and secreted with bile into the duodenum.

In the liver, bile acids are formed predominantly from cholesterol. Bile acids, which are present in different proportions in the bile of different animals, differ only in the number and spatial arrangement of their hydroxyl groups. Human bile contains principally cholic acid and small quantities of deoxycholic, lithocholic, and chenodeoxycholic acids. Very few bile acids are found in a free state in the bile; a large proportion of them are bound in the form of so-called conju-gate acids, such as glycocholic and taurocholic acid, which are formed as a result of the addition of bile acids to glycine and taurine.

Bile acids promote the digestion of fats in the intestinal tract; they activate the lipase of the pancreatic and intestinal juices and promote the emulsification of fats, stimulating their absorption in undecomposed form; they increase the speed of absorption of poorly soluble calcium salts of fatty acids by forming readily soluble complexes with them; and they greatly intensify intestinal peristalsis. In the intestinal tract a large proportion of the bile acid undergoes reverse absorption, and through the portal-vein system it enters the liver, where it is completely retained. The total bile-acid con-tent in the blood averages 0.8 mg percent; in the bile of the liver, 0.9–1.8 percent; and in cystic bile, 5.7–10.8 percent. When there is a considerable increase in the bile-acid content of the blood, the bile acids begin to be discharged with the urine. A decrease in bile-acid content is almost always accompanied by the precipitation of cholesterol, the principal constituent of gallstones.

G. A. SOLOV’EVA

bile acids

bile

[bīl] a clear yellow or orange fluid produced by the liver. It is concentrated and stored in the gallbladder, and is poured into the small intestine via the bile ducts when needed for digestion. Bile helps in alkalinizing the intestinal contents and plays a role in the emulsification, absorption, and digestion of fat; its chief constituents are conjugated bile salts, cholesterol, phospholipid, bilirubin, and electrolytes. The bile salts emulsify fats by breaking up large fat globules into smaller ones so that they can be acted on by the fat-splitting enzymes of the intestine and pancreas. A healthy liver produces bile according to the body's needs and does not require stimulation by drugs. Infection or disease of the liver, inflammation of the gallbladder, or the presence of gallstones can interfere with the flow of bile.bile acids steroid acids derived from cholesterol; classified as primary, those synthesized in the liver, e.g., cholic and chenodeoxycholic acids, or secondary, those produced from primary bile acids by intestinal bacteria and returned to the liver by enterohepatic circulation, e.g., deoxycholic and lithocholic acids.bile ducts the canals or passageways that conduct bile. There are three bile ducts: the hepatic duct drains bile from the liver; the cystic duct is an extension of the gallbladder and conveys bile from the gallbladder. These two ducts may be thought of as branches that drain into the “trunk,” or common bile duct. The common bile duct passes through the wall of the small intestine at the duodenum and joins with the pancreatic duct to form the hepatopancreatic ampulla, or ampulla of Vater. At the opening into the small intestine there is a sphincter that automatically controls the flow of bile into the intestine.
The bile ducts may become obstructed by gallstones, benign or malignant tumors, or a severe local infection. Various disorders of the gallbladder or bile ducts are often diagnosed by ultrasonography, radionuclide imaging, and x-ray examination of the gallbladder and bile ducts using a special contrast medium so that these hollow structures can be clearly outlined on the x-ray film.

bile ac·ids

steroid acids found in bile, for example, taurocholic and glycocholic acids, used therapeutically when biliary secretion is inadequate and for biliary colic. Their physiologic roles include fat emulsification. Their synthesis is reduced in disorders of the peroxisomes.

bile ac·ids

(bīl as'idz) Steroid acids found in bile (e.g., taurocholic and glycocholic acids), used therapeutically when biliary secretion is inadequate and for biliary colic. Their physiologic roles include fat emulsification.

bile acids

Cholic and chenodeoxycholic acids. These are produced in the liver from cholesterol, linked with glycine or taurine to form BILE SALTS and passed into the small intestine in the bile.

单词	bile acids
释义	DictionarySeebile acid Bile Acids Bile Acids steroid monocarboxylic acids, derivatives of cholanic acid that are formed in the liver of man and animals and secreted with bile into the duodenum. In the liver, bile acids are formed predominantly from cholesterol. Bile acids, which are present in different proportions in the bile of different animals, differ only in the number and spatial arrangement of their hydroxyl groups. Human bile contains principally cholic acid and small quantities of deoxycholic, lithocholic, and chenodeoxycholic acids. Very few bile acids are found in a free state in the bile; a large proportion of them are bound in the form of so-called conju-gate acids, such as glycocholic and taurocholic acid, which are formed as a result of the addition of bile acids to glycine and taurine. Bile acids promote the digestion of fats in the intestinal tract; they activate the lipase of the pancreatic and intestinal juices and promote the emulsification of fats, stimulating their absorption in undecomposed form; they increase the speed of absorption of poorly soluble calcium salts of fatty acids by forming readily soluble complexes with them; and they greatly intensify intestinal peristalsis. In the intestinal tract a large proportion of the bile acid undergoes reverse absorption, and through the portal-vein system it enters the liver, where it is completely retained. The total bile-acid con-tent in the blood averages 0.8 mg percent; in the bile of the liver, 0.9–1.8 percent; and in cystic bile, 5.7–10.8 percent. When there is a considerable increase in the bile-acid content of the blood, the bile acids begin to be discharged with the urine. A decrease in bile-acid content is almost always accompanied by the precipitation of cholesterol, the principal constituent of gallstones. G. A. SOLOV’EVA bile acids bile [bīl] a clear yellow or orange fluid produced by the liver. It is concentrated and stored in the gallbladder, and is poured into the small intestine via the bile ducts when needed for digestion. Bile helps in alkalinizing the intestinal contents and plays a role in the emulsification, absorption, and digestion of fat; its chief constituents are conjugated bile salts, cholesterol, phospholipid, bilirubin, and electrolytes. The bile salts emulsify fats by breaking up large fat globules into smaller ones so that they can be acted on by the fat-splitting enzymes of the intestine and pancreas. A healthy liver produces bile according to the body's needs and does not require stimulation by drugs. Infection or disease of the liver, inflammation of the gallbladder, or the presence of gallstones can interfere with the flow of bile.bile acids steroid acids derived from cholesterol; classified as primary, those synthesized in the liver, e.g., cholic and chenodeoxycholic acids, or secondary, those produced from primary bile acids by intestinal bacteria and returned to the liver by enterohepatic circulation, e.g., deoxycholic and lithocholic acids.bile ducts the canals or passageways that conduct bile. There are three bile ducts: the hepatic duct drains bile from the liver; the cystic duct is an extension of the gallbladder and conveys bile from the gallbladder. These two ducts may be thought of as branches that drain into the “trunk,” or common bile duct. The common bile duct passes through the wall of the small intestine at the duodenum and joins with the pancreatic duct to form the hepatopancreatic ampulla, or ampulla of Vater. At the opening into the small intestine there is a sphincter that automatically controls the flow of bile into the intestine. The bile ducts may become obstructed by gallstones, benign or malignant tumors, or a severe local infection. Various disorders of the gallbladder or bile ducts are often diagnosed by ultrasonography, radionuclide imaging, and x-ray examination of the gallbladder and bile ducts using a special contrast medium so that these hollow structures can be clearly outlined on the x-ray film. bile ac·ids steroid acids found in bile, for example, taurocholic and glycocholic acids, used therapeutically when biliary secretion is inadequate and for biliary colic. Their physiologic roles include fat emulsification. Their synthesis is reduced in disorders of the peroxisomes. bile ac·ids (bīl as'idz) Steroid acids found in bile (e.g., taurocholic and glycocholic acids), used therapeutically when biliary secretion is inadequate and for biliary colic. Their physiologic roles include fat emulsification. bile acids Cholic and chenodeoxycholic acids. These are produced in the liver from cholesterol, linked with glycine or taurine to form BILE SALTS and passed into the small intestine in the bile.
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