Nutritional and metabolic characterization of a thiamine-deficient rat model.
The effects of a thiamine-deficient diet on plasma and tissue vitamin concentrations and on whole-body glucose metabolism were assessed. Male Sprague-Dawley rats (175 to 200 g body weight) fed a thiamine-deficient (TD) or nutritionally complete purified diet were used for plasma thiamine mononitrate and monophosphate and for red blood cell and tissue thiamine pyrophosphate (TPP) determinations weekly for up to 5 weeks. Additional rats were used for assessment of basal glucose kinetics by using a primed constant infusion of [3-3H]glucose. Plasma thiamine mononitrate levels decreased 60% at 1 week and were undetectable after 5 weeks on the diet. Plasma thiamine monophosphate decreased 80% after 1 week on the TD diet, and levels were undetectable after 4 weeks on the diet. Red blood cell TPP in the TD group decreased progressively with time: 54% at 1 week, 86% at 3 weeks, and 92% at 5 weeks. At 1 and 4 weeks, the decrease in tissue TPP was significant in the liver (65% and 89%, respectively), gut (52% and 94%, respectively), spleen (40% and 60%, respectively), and skeletal muscle (37% and 76%, respectively), with the brain (7% and 84%, respectively) showing the slowest initial rate of depletion. The TD diet did not alter plasma glucose concentrations, but it increased plasma lactate by 75% and plasma pyruvate by 50% to 75%. Rates of hepatic glucose production and peripheral glucose utilization were not different between the control and TD rats at 2 weeks, but they were 25% higher in the TD rats after 6 weeks on the diet.(ABSTRACT TRUNCATED AT 250 WORDS)
Molina
P E
PE
Department of Surgery, SUNY at Stony Brook 11794-8191.
Myers
N
N
Smith
R M
RM
Lang
C H
CH
Yousef
K A
KA
Tepper
P G
PG
Abumrad
N N
NN
D000818:Animals; D001835:Body Weight; D004032:Diet; D004195:Disease Models, Animal; D002149:Energy Intake; D005508:Food Deprivation; D005947:Glucose / Q000378:metabolism*; D007700:Kinetics; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D013831:Thiamine / Q000032:analysis / Q000097:blood; D013832:Thiamine Deficiency / Q000097:blood / Q000378:metabolism*
D005947:Glucose; D013831:Thiamine