2580
EFFECTS
OF VITAMIN A DEFICIENCY ON EMBRYONIC BRAIN DEVELOPMENT IN RATS Chen LN, Li TY & Qu P Children��s Hospital, Chongqing University of
Medical Sciences, Chongqing, China Objective: To study the effect of
vitamin A deficiency (VAD) on embryonic brain development in rats and it��s
mechanisms in molecualar biology. Methods: 9 female Wistar rats were
randomly divided into severe VAD (SVAD), marginal VAD (MVAD) and Control
groups. The rats were fed with vitamin A (VA) O IU/kg, 400 IU/kg and 6500
IU/kg diets respectively starting from 3 weeks before pregnancy onwards.
Body weight, brain weight, serum VA level, brain VA content and protein
content, brain cell proliferative cycle and the expression of RAR��, RAR��,RXR�� and D2R Mrna were measured at birth. Results: (1) There were significant differences in VA level
in serum and brain tissue between groups. (2) The body and brain weights in
SVAD group were lighter than those in both MVAD and Control group. (3) The
brain protein content in SVAD group was significant lower than that of
Control group. (4) The cell proliferative index (PI) in SVAD group was
significantly lower than that of Control group. (5) The expression of RAR ��, RAR��,RXR�� ,
RXR�� and D2R mRNA in SVAD group and MVAD group were lower
than those of Control group. Conclusion: (1) VAD can decrease
brain VA content and affect embryonic brain development. (2) Brain
development defects in embryonic VAD rats including brain weight loss,
decrease of brain protein content, and brain cell proliferation inactive.
(3) The embryonic brain development defects may be related with the
decreased expression of RAR��, RAR��, RXR�� ,
and D2R in brain cell.