Effect of thiamine deficiency in pregnant and lactating rats on the brain of their offspring.

In an attempt to create a model of human infantile beriberi, pregnant rats were fed, from the 10th day of pregnancy through lactation, a low-thiamine diet. Controls were either pair-fed or offered a nutritionally complete diet ad libitum. Dams exhibited symptoms of thiamine deficiency after 30 days on the experimental diet, whereas the their pups displayed signs of thiamine deficiency from the 14th postnatal day. Brain transketolase activity was depressed in day-old thiamine-deficient pups, and brain pyruvic acid levels were elevated after the 7th postnatal day. From the 14th postnatal day, brains of thiamine-deficient pups contained less phospholipids, cerebrosides and cholesterol than those of both controls. On the 21st day, weight and lipid content of brains of thiamine-deficient and of pair-fed pups were lower than those of normal controls. In some rats rehabilitation with thiamine was begun on the 19th day, and after 23 days, brain cerebroside content was still lower in the experimental group than in both controls. Since cerebrosides are an essential component of myelin, this finding may suggest damage of the myelin sheath.