Table 1.

Calorimetry measurements

	PBS		Leptin
	Saline	Hydrogel	Saline	Hydrogel
Light phase RER
Day −1	0.90 ± 0.02	0.90 ± 0.01	0.91 ± 0.01	0.91 ± 0.01
Day 4	0.86 ± 0.02a	0.87 ± 0.02a	0.79 ± 0.01b	0.77 ± 0.01b
Day 7	0.87 ± 0.02a	0.87 ± 0.01a,b	0.82 ± 0.03b,c	0.78 ± 0.01c
Dark phase RER
Day −1	0.95 ± 0.02	0.94 ± 0.01	0.96 ± 0.01	0.95 ± 0.01
Day 4	0.93 ± 0.03a	0.93 ± 0.02a	0.84 ± 0.01b	0.84 ± 0.01b
Day 7	0.93 ± 0.02a	0.92 ± 0.01a	0.88 ± 0.02b	0.85 ± 0.01b
Total daily energy expenditure, kcal·rat−1·24 h−1
Day −1	187 ± 12	183 ± 10	187 ± 14	208 ± 9
Day 3	181 ± 12a,b	172 ± 10b	208 ± 13a,b	216 ± 11a
Day 6	179 ± 11a,b	163 ± 9b*#	199 ± 8a	191 ± 10a,b*#

Data are means ± SE for groups of 7–9 rats. RER, respiratory exchange ratio. Values that do not share a common superscripted letter are significantly different at P < 0.05

^*Significant difference for a specific group between baseline and infusion periods;

^#significant difference for a specific group before and after placement of hydrogel.