INCREASED GLUCOSE DEPENDENCE IN RESTING, IRON-DEFICIENT RATS
INCREASED GLUCOSE DEPENDENCE IN RESTING, IRON-DEFICIENT RATS
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DOI:
10.1152/ajpendo.1987.253.4.e461
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发表时间:
1987-10-01
影响因子:
--
通讯作者:
DALLMAN, PR
中科院分区:
文献类型:
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作者:
BROOKS, GA;HENDERSON, SA;DALLMAN, PR
Rates of blood glucose and lactate turnover were assessed in resting iron-deficient and iron-sufficient (control) rats to test the hypothesis that dependence on glucose metabolism is increased in iron deficiency. Male Sprague-Dawley rats, 21 days old, were fed a diet containing either 6 mg iron/kg feed (iron-deficient group) or 50 mg iron/kg feed (iron-sufficient group) for 3-4 wk. The iron-deficient group became anemic, with hemoglobin levels of 6.4 .+-. 0.2 compared with 13.8 .+-. 0.3 g/dl for controls. Rats received a 90-min primed continuous infusion of D-[6-3H]glucose and sodium L-[U-14C]lactate via a jugular catheter. Serial samples were taken from a carotid catheter for concentration and specific activity determinations. Iron-deficient rats had significantly (P < 0.05) higher blood glucose (7.1 .+-. 0.3 vs. 6.1 .+-. 0.2 mM) and lactate concentrations than controls (1.0 .+-. 0.1 vs. 0.8 .+-. 0.1 mM). The iron-deficient group had a significantly higher glucose turnover rate (67 .+-. 2 vs. 58 .+-. 4 .mu.mol .cntdot. kg-1 .cntdot. min-1) than the control group. Significantly more metabolite recycling in iron-deficient rats was indicated by greater incorporation of 14C (from infused [14C]-lactate) into blood glucose. Assuming a carbon crossover correction factor of 2, half of blood glucose arose from lactate in deficient animals. By comparison, only 25% of glucose arose from lactate in controls. Lack of a difference in lactate turnover (irreversible disposal) rates between deficient rats and controls (191 .+-. 26 vs. 163 .+-. 15 .mu.mol .cntdot. kg-1 .cntdot. min-1) ws attributed to 14C recycling. The results indicate a greater dependence on glucose metabolism in iron-deficient rats.