il\VOLVEMENT OF RETII\OIC ACID II{ - MSpace at the University of ...

Lc. Retinoic acid receptors
Three weeks after the treatment, protein levels of each of the individual RAR and
RXR receptors (a, p, 1) were examined in the hearts of ADR" ADR+PROB, PROB and
CONT groups (Fig. 8). The administration of adriamycin in ADR group animals caused
84o/o increase in the RAR c¿ receptor protein levels, while the same group exhibited 14%
decrease in RAR y and a 510á decrease in RXR þ (51%) when compared to CONT group
(Fig. S). The expression of other retinoic acid receptors in the ADR group was not found
to be significantly different from the CONT group (Fig. 8). ADR group hearts also
exhibited some increase in the total RAR receptors. The total RXR levels did not differ
from control (Fig. 9). The RAR/RXR ratio in the ADR group was increased by 60%
when compared to control (Fig. 10).
The treatment with probucol in the PROB group hearts resulted in an increased
expression of all of the individual RAR and RXR receptors when compared to CONT
group (RAR a: 104Yo, RAR B: 44%,RAR y: 45Yo, RXR cr: 58%, RXR g'. 50% and RXR
y. 53%) (Fig.8). The PROB group exhibited a significant increase in the combined RAR
and RXR receptor levels when compared to CONT (64% and 54Yo) (Fig.9), but no
significant increase in the RAR/RXR ratio (Fig.10).
Treatment with antioxidant probucol in the ADR+PROB group caused a
significant increase in all of the individual RAR and RXR receptors when compared to
control (RAR u.:30Yo, RAR B: 46%, RAR y:45o/o, RXR c¿: 29yo,RÆ.þ: 48% and RAR
y. l4%) (Fig.8). ADR+PROB group showed a significant increase in the RAR P, RAR y,
RXR c¿ and RXR B expression when compared to ADR group (37yo,38Yo, I3Yo and
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