Tissue-specific changes in Rdh10 and Rdh1 expression duringfasting and re-feeding are consistent with a complex contributionof atRA to regulating intermediary metabolism. Epididymalwhite adipose tissue and pancreata do not express Rdh1(data not shown), but express Rdh10. The non-responsivenessof Rdh10 in epididymal white adipose tissue to changes inenergy balance allows several interpretations, including thepresence of another Rdh that responds to changes in energystatus, or feeding versus fasting does not modify atRA epididymalwhite adipose tissue concentrations in adult mice. Thesepossibilities are the subjects of ongoing studies. The decrease inRdh10 expression in pancreas during re-feeding is consistentwith the requirement for retinoids in pancreatic development(48, 49) and function (50, 51), and also a subject of ongoingstudies. Suppression of Rdh1 in liver by re-feeding, and Rdh10in liver and kidney, relate insulin action with atRA signaling intwo gluconeogenic tissues. Decreased Dhrs3 expression in liverof re-fed versus fasted mice is consistent with a mutually activatinginteraction of Rdh10 and Dhrs3 (23), and the reductionin atRA biosynthesis. Evidently, energy metabolism affects Rdh expression in multiple tissues to regulate retinoid signalingeffects as feedback to regulation of energy disposition by atRA.