RER during day and night in intact (A), adrenal denervated (B), and ADX (C) SAP and DSAP rats (left panels). Day and night periods are indicated by white and black bars, respectively, above the x-axis. Averages over 2 days for the diurnal and nocturnal periods are presented as bar graphs (right panels). Adrenal intact DSAP rats had a higher RER during both day and night than SAP rats. ADX abolished that effect but did not disrupt the day-night rhythm of the RER; n = 7–8 rats/group. *, P < .05 vs daytime within the same treatment group; #, P < .05 vs SAP rats.