Effect of Thiamine Deficiency and Thiamine Repletion on Neutral Glyceride, Total and Free Cholsterol, Phospholipids, and Plasmalogens in Rat Liver

Abstract

Intraperitoneal injection of 1 mg of thiamine in severely thiamine-deficient rats is followed by a 3- and 20-fold elevation of liver total cholesterol and neutral glycerides, respectively. These elevations continue up to 8 and 20 times normal after a second thiamine injection.Phospholipid levels per gram of liver or per 100 g of body weight fall to below normal during development of thiamine deficiency. Little change in plasmalogens occurred, however, when expressed in either manner although there was a tendency for them to fall slightly below the ad libitum-fed control level. After a single thiamine injection, phospholipids tend to return to normal, whereas plasmalogens increase to far above normal levels. A second injection of thiamine decreases phospholipids to below normal, which then return nearly to normal. Plasmalogens return nearly to normal without fluctuating after a second thiamine injection.During thiamine deficiency the ratio of free to total cholesterol is significantly higher than normal, suggesting either a breakdown in the cholesterol esterification system or a severe deficiency of fatty acids available for esterification. After thiamine repletion the ratio rapidly falls to well below normal.After thiamine repletion fine droplet lipidosis and a striking increase in glycogen in the portal areas precedes the massive paracentral fatty change which is reflected biochemically. When massive fatty deposition occurs, stainable glycogen decreases. Cellular regenerative activity after thiamine repletion is slight, indicating that the changes observed with thiamine repletion are unassociated with cell destruction and subsequent cell proliferation.Although oral or parenteral administration of thiamine generally produced similar effects on liver lipids, the magnitude of the effects on total cholesterol and plasmalogens was much greater with parentral administration.