Distinct effects of three bile salts on cholesterol solubilization by oleate-monoolein-bile salt micelles.

Micellar cholesterol solubilities in bile salt-monoolein-oleic acid systems have been determined. Whatever the bile salt/oleyl compounds ratio, taurochenodeoxycholate solubilizes more cholesterol than taurocholate and much more than tauroursodeoxycholate. At pH 6.7, the cholesterol solubility limit is about the same with either oleate or monoolein. Cholesterol solubility falls in oleate-bile acid mixtures as the pH is raised. The capacity for supersaturation with cholesterol is greater for bile salt-monoolein than for bile salt-oleate micelles. For the latter it decreases as pH increases.