Possible Interaction: Tretinoin and Triiodothyronine

“Altogether these data suggest that T3 and ATRA can cooperate in modulating in vitro erythropoiesis although having individual effects at different but overlapping steps along the erythroid pathway.”

“Furthermore, T3 and ATRA used in combination had more pronounced effects than when used alone, but only at their respective optimal concentrations, indicating that these effects were additive rather than synergistic.”

“When used alone, neither T3 nor ATRA could affect NFS-60 cell proliferation in response to Epo; however, T3 and ATRA had an anti-proliferative effect when used together.”

“These data suggest that retinoids act via a gene-dependent mechanism to modulate maximal, but not half-maximal, responses to T3 in HepG2 cells with the specificity of RA greater than that of 9-cis-RA.”

“With T3 (10 nM) together with RA (3, 10, or 100 nM), the maximal SHBG responses were reduced to 193 +/- 24%, 151 +/- 5% and 132 +/- 30%, respectively.”

“9-cis RA inhibited the T3 response, indicating a hormonal cross-talk among the subfamily of nuclear receptors.”

“The stimulation by both RA and T3 was dose dependent and was accompanied by stimulation of hPL messenger RNA levels.”

“The present finding that T3 potentiates RA-induced HL-60 cell differentiation may raise the possibility that T3 supplement increases clinical remission in APL patients who are treated with RA.”

“Interestingly, T3 strongly enhanced the action of RA , suggesting cooperative action of the two receptors in modulating erythroid differentiation.”

“A concentration as low … 10(-10) M retinoic acid shifted the dose-… both T4 and T3 so that the concentration of each associated with maximal enzyme stimulation was 10(-9) M instead of …) M. Retinoic acid displaced [125I]T4 binding to red cell membranes as effectively as unlabeled T4.”

“These results indicate that retinoic acid can partially block the T4 and T3 stimulation of Ca2+-ATPase in human red cell membranes and suggest a physiologic role for the retinoid as a modulator of this peripheral action of thyroid hormone.”

“Interactions of T3 with retinoic acid signaling through the control of retinoic acid metabolism are likely to be important during development.”

“ T3 had opposing influences on retinoic acid synthesizing enzymes, increasing the expression of Aldh1a1, and decreasing Aldh1a3, while increasing the retinoic acid degrading enzyme Cyp26b1.”

“The administration of T3 to these vitamin A-deprived rats reversed the reduction in mRNA levels of RA and T3 nuclear receptors and in mRNA and protein levels of target genes in this region.”

“The combination of RA and T3 treatment caused synergistic inhibition of rat TSHbeta gene expression in the presence of RAR/RXR and TR.”