The effect of bile, bile acids and detergents on calcium absorption in the chick

Abstract

1. Bile from rachitic or normal chicks causes an immediate increase in the intestinal absorption of soluble calcium in rachitic and vitamin D(3)-treated chicks as tested in vivo by intestinal-loop and oral-dosing methods. 2. This effect is apparently solely due to the taurine-conjugated bile acids present in the bile and is independent of the action of vitamin D. 3. Chick bile and bile acids can increase the solubility and the absorption of calcium presented as sparingly soluble calcium hydrogen phosphate. 4. In addition, bile is necessary to some extent at least for the intestinal absorption of vitamin D(3) in the chick and this would indirectly enhance the absorption of calcium. 5. Thus bile is capable of a threefold action in the absorption of calcium in the chick. It is suggested that the direct action on sparingly soluble forms of calcium is of considerable physiological importance since most of the calcium in the normal bird's diet would be in this form. 6. Bile acids enhance the absorption of calcium in all regions of the small intestine of the chick. 7. Of a range of bile acids and detergents tested for enhancement of calcium absorption, various taurine-conjugated bile acids and sodium lauryl sulphate, an anionic detergent, are effective. A non-ionic detergent (Tween 80) and a cationic detergent (Zephiran) are without effect. 8. The ability of a substance to increase directly the intestinal absorption of soluble calcium appears to depend to some extent on an anionic detergent action, i.e. the ability to form a salt or complex soluble to some extent in both aqueous and lipid phases. 9. In chicks the immediate deposition of calcium ((45)Ca) in the bones closely reflects any increase in plasma calcium radioactivity regardless of the cause of the increase and regardless of the vitamin D(3) status. Although sodium lauryl sulphate can increase markedly the calcium absorption from the gut and the immediate deposition in the bones it has no significant effect on rickets. 10. Some of the implications of these findings are discussed.

An evaluation of the importance of gastric acid secretion in the absorption of dietary calcium.

“…A third possible explanation for the seeming unimportance of gastric acid is that calcium carbonate, while insoluble in water, may become soluble in biliary or pancreatic fluids. Bile acids can increase the in vitro solubility of CaHPO4 and enhance the absorption of calcium in chicks independent of the action of vitamin D (24,25). However, in unpublished results in our laboratory, we have been unable to show that solutions containing pancreatic enzymes and bile acids enhance the solubility of calcium carbonate.…”

“Activation” of vitamin D by the liver

“…Unfortunately, severe chronic liver insufficiency usually associates in various proportions with cirrhosis and bile retention. It is now clear that bile salts improve absorption of calcium (8,9) and are necessary for the absorption of vitamin D (10)(11)(12)(13)(14). This certainly accounts to a large extent for the osteodystrophy resistant to oral administration of vitamin D observed in biliary obstruction without major liver parenchymal damage or in bile fistulae (11,47,53,54).…”

“…Impaired intestinal absorption of calcium (8,9) and vitamin D (10)(11)(12)(13)(14) due to the lack of bile salts has been generally implicated in the etiology of the osteodystrophy. However, several reports indicate that in addition to an occasional poor intestinal absorption of vitamin D, the metabolism and the effects of this vitamin were directly altered by the liver disease.…”

Influence of Cholic Acid on the Utilization of Fats in the Growing Chicken

“…Although the predominantly functional bile salt in chicks is chenodeoxycholic acid (Webling and Holdsworth, 1965), these studies were conducted with the readily available cholic acid. The reference diet (Table 1) was a purified diet with a calculated protein content of 25.1 percent and a calculated metabolizable energy (M. E.) value of 3.40 Kcal./g.…”