The Absorption and Excretion of Tocopherol in Laennec's Cirrhosis 1

Abstract

The plasma tocopherol level is often low in cirrhosis (1, 2). Whether such low values reflect alterations in the absorption, utilization or excretion of tocopherol related to liver damage, or are the result of a decreased dietary intake is not known. Previous attempts to investigate tocopherol metabolism in liver disease have been limited to tests of tocopherol tolerance based on plasma curves (1, 2) and have shed little light on the problem, largely because tolerance tests cannot be interpreted in terms of absorption and utilization without parallel studies of excretion and storage. The present report is concerned with the results of such studies in Laennec's cirrhosis. These have been made possible by the recent development of analytical methods for the determination of tocopherol in excreta.In a preliminary investigation (1) of a group of subjects with a variety of liver diseases, including Laennec's cirrhosis, it was found that the plasma tocopherol level was significantly lower than in young healthy adults, but that it did not differ significantly from that of randomly-selected, hospitalized convalescent controls without evidence of liver disease. Moreover, there was no correlation between the plasma level and the degree of hepatic dysfunction, suggesting that low levels might be related to extrahepatic factors. Oral tocopherol tolerance tests were carried out to exclude impairment of absorption as one of these factors. These revealed relative flat plasma curves, but the lack of any correlation between the height of the curve and the original plasma level did not appear to be consistent with the interpretation that low plasma concentrations were the result of impaired absorption. Attempts to investigate tocopherol utilization by means of parenteral tolerance tests 1

The Effects of Experimental Hepatobiliary Disease on Certain Aspects of Tocopherol Metabolism in the Rat1

“…Thus, the level at which equilibrium is established may be influenced by the dietary intake of tocopherol, its rate of ab-TOCOPHEROL IN EXPERIMENTAL HEPATQBILIARY DISEASE sorption from the intestinal tract, and the capacity of the tissues to store, utilize, and release tocopherol. As far as is known, endogenous synthesis is not a factor, and, as shown previously, the negligible losses of tocopherol in the bile and urine are of little consequence (2). The binding capacity of the serum proteins may affect the amount of tocopherol retained, and may govern the maximum concentration attainable in the serum.…”

“…However, repeated doses raised the concentration in a normal manner, while the fraction recovered in the feces was even smaller than in normal subjects (2,3), suggesting that intestinal absorption was not impaired. One possible explanation for these findings was that the tissue stores of tocopherol were depleted as the consequence of an antecedent dietary deficiency, and that the low concentrations in the feces and the relatively flat tolerance curves were indicative of greater absorption and more rapid transfer of tocopherol from the intestinal tract to the tissues.…”

Chitosan/PLGA Particles for Controlled Release of α-Tocopherol in The GI Tract Via Oral Administration

“…A biphasic release profile was observed for CP8 (8% aT initial loading) particles, with CP8 releasing considerably more aT than CP16 and CP24 particles (Figure 6). Chi/PLGA particles for all three initial loadings, 8,16 and 24% had no significant difference in size ( Figure 1A). Therefore, the location of the vitamin as opposed to particle size affected the diffusion rate of aT.…”

“…Organic phase was formed with 2 w/v% PLGA and aT dissolved in ethyl acetate at three different initial loading concentrations (8,16 and 24% relative to PLGA mass). Aqueous phase was formed with 11 mM lecithin dissolved in ethyl acetate saturated water.…”

“…Due to these limitations, the efficiency of absorption of vitamin E and a -tocopherol (aT) acetate, respectively, were reported to be approximately 36 and 44% in normal subjects [16].…”