Altered metabolism and superoxide generation in neural tissue of
rat embryos exposed to high glucose.
Yang, Xiaolin, L. A. H[circumflex]ikan Borg, and Ulf J. Eriksson.
Department of Medical Cell Biology, University of Uppsala
APStracts 3:0211E, 1996.
Oxygen uptake and glucose utilization of embryonic and fetal neural
tissue of normal and diabetic rat pregnancy were studied. Exposure to
50 mmol/L glucose inhibited oxygen uptake of embryonic neural tissue
of normal rats by 28 % at gestational day 9 (P < 0.001), and 20 % at
day 10 to 12 and at day 15 (P < 0.001), and stimulated glucose
utilization by 132 % at day 9 (P < 0.001), 50 % at day 10 and 11 (P <
0.01), 168 % at day 12 (P < 0.001), and 338 % at day 15 (P <
0.001), indicating a Crabtree effect. The glucose-altered metabolism
led to production of superoxide by the tissue, which was 1.8 to 2.4
nmol/h/ g DNA at day 9 to 12, and 1.2 nmol/h/ g DNA at day 15. The
embryonic neural tissue of diabetic rats showed a diminished
metabolic sensitivity to high glucose exposure, suggesting an
impaired mitochondrial function. Consequently, the glucose induced
superoxide production was not detected in the tissue of embryos of
diabetic rats. The data suggest that high concentration of glucose
alters embryonic and fetal metabolism and causes generation of
superoxide. Prolonged duration of the glucose-induced metabolic
changes may impair cellular function and lead to embryonic
dysmorphogenesis.
Received 18 June 1996; accepted in final form 12 September 1996.
APS Manuscript Number E295-6.
Article publication pending Am. J. Physiol. (Endocrinol. Metab.).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 5 November 1996