Abstract
The absorption and metabolic fate of dietary squalene were investigated on the rat by administering a single oral dose of3H-squalene and14C-cholesterol. Experiments on rats with cannulated thoracic duct revealed that3H-squalene was, like14C-cholesterol, absorbed through the lymphatic vessels and that ca. 20% of absorbed3H-squalene was cyclized to sterols during the transit through the intestinal wall. Feces contained3H-sterols, indicating that newly synthesized mucosal sterols had been secreted into the gut lumen. In intact animals,3H-squalene appeared in the circulation more rapidly than14C-cholesterol and did not persist to any significant extent in the squalene-rich adipose and muscle tissues. The increase in dietary squalene load (8–48 mg) decreased the absorption percentage of3H-squalene (45–26%) but did not affect the absorption of14C-cholesterol (47%). Determination of fecal steroids revealed that during the first days absorbed3H-squalene was eliminated to a significantly higher extent than14C-cholesterol as fecal bile acids (34% vs 11%). The experiments indicate that the rat intestine has a marked capacity for absorbing dietary squalene and that the absorbed squalene is preferentially converted to bile acids in the liver.
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Tilvis, R.S., Miettinen, T.A. Absorption and metabolic fate of dietary3H-squalene in the rat. Lipids 18, 233–238 (1983). https://doi.org/10.1007/BF02534554
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DOI: https://doi.org/10.1007/BF02534554