Pigment stones

K. Nakai, S. Tazuma, T. Nishioka and K. Chayama, Inhibition of cholesterol crystallization under bilirubi deconjugation partial characterization of mechanism whereby infected bile accelerates pigment stone formation. Biochem. Biophys. Acta 1632 (2003) 48-54. 

The cholesterol excreted with the bile is poorly water-soluble. Together with phospholipids and bile acids, it forms micelles (see p. 270), which keep it in solution. If the proportions of phospholipids, bile acids and cholesterol shift, gallstones can arise. These mainly consist of precipitated cholesterol (cholesterol stones), but can also contain Ca " salts of bile acids and bile pigments (pigment stones). 

Contraindications Allergy to bile acids, calcified cholesterol stones, chronic hepatic disease, radiolucent bile pigment stones, radiopaque stones... 

Fig. 32.1 CholestBrol-calcium-pigment stone a rare specimen showing a striking coloured/chemical development (here a so-called tiger-eye stone) (at our disposal). Diagnosis obstructive cholangitis due to Mirizzi s syndrome...

The importance of the type of carbohydrate was studied in hamsters receiving diets containing 2% lard (60). Glucose (72.3%) gave 100% cholesterol stones, whereas sucrose gave predominantly amorphous pigment stones only two of seven contained cholesterol. Rice starch and lactose (72.3 7o) completely prevented lithiasis. In a second series, when rice starch was sub-... 

In a study on the effects of hormones, testosterone-treated males and estrogen-treated females had a lower incidence of amorphous pigment stones than gonadectomized animals but may have had a higher incidence of cholesterol stones the total incidence was similar (66). Progesterone, on the other hand, lowered the incidence of cholesterol stones in females. Deoxycorticosterone had no clear effect on stone formation. Desiccated thyroid lowered and methyl thiouracil raised the ratio of cholesterol/amorphous pigment stones. 

Shioda (82) investigated the effect of dietary constituents on gallstone formation in golden hamsters. Like Dam, he found that hamsters on a low-fat diet frequently formed cholesterol gallstones. The addition of unsaturated fats (codliver oil, sesame oil) prevented cholesterol stones but allowed the development of amorphous pigment stones. Cholesterol stones correlated well with increased cholesterol and decreased bile acids and phospholipids in hepatic bile that was consequently supersaturated with respect to cholester-... 

Raw starch (/5-starch) protected against gallstones, but when predigested with enzymes (83) or cooked (84) the starch (a-starch) became absorbable and the incidence of cholesterol stones was as great as in animals on the glucose, fat-free diet. The addition of neomycin to the a-starch, butterfat, 1 % cholesterol diet protected completely against cholesterol stones but resulted in a 100% incidence of amorphous pigment stones (84). 

The increased glycine/taurine ratio in bile from hamsters with amorphous pigment stones is not unexpected, considering the composition of the stones, but the reason for this change is unclear. The increase ratio results from a relative deficiency of taurine and could be produced by a decreased protein intake, which supplies the sulfur-containing amino acids used for taurine synthesis, or by an excessive fecal loss of taurine conjugates, as in... 

Thus only radiolucent cholesterol-rich gallstones may be treated medically, while radioopaque pigment stones are insoluble... 

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