Table 1.

MC4R or MC5R Were Expressed Alone or in Combination With One of the Different MRAPs in HEK-293 Cells Expressing a Reporter Gene Under the Control of CREs

	MC4R	MC4R MRAP1	MC4R MRAP2a	MC4R MRAP2b	MC5R	MC5R MRAP1	MC5R MRAP2a	MC5R MRAP2b
α-MSH	1.30 × 10−8	8.49 × 10−9	2.14 × 10−8	1.70 × 10−8	1.16 × 10−9	1.09 × 10−9	1.37 × 10−9	8.78 × 10−10
	[±2.49 × 10−8]	[±3.37 × 10−9]	[±3.92 × 10−8]	[±2.43 × 10−8]	[±3.19 × 10−9]	[±1.07 × 1010]	[±1.78 × 10−9]	[±9.61 × 10−10]
ACTH(1–24)	1.77 × 10−7	6.15 × 10−7	8.49 × 10−9 a	4.9 × 10−8	9.73 × 10−10	9.01 × 10−10	1.41 × 10−9	6.80 × 10−10
	[±6.26 × 10−7]	[±3.84 × 10−7]	[±3.37 × 10−9]	[±5.1 × 10−8]	[±3.02 × 10−10]	[±1.47 × 10−10]	[±6.68 × 10−9]	[±2.08 × 10−10]
ACTH(1–24) + AGRP			3.57 × 10−7 b
			[±6.77 × 10−7]

The mean of the reporter activation, expressed as percentage of the basal level, for each concentration of melanocortin agonist (hACTH1–24 or α-MSH), was calculated from 3 independent experiments and the resultant data were fitted to logistic curves using Qtiplot free software. For statistical comparisons, data from each independent experiment (n = 3) were fitted to dose-response curves and ED₅₀ average values (M) compared by one-way ANOVA and significant differences were indicated. Numbers in brackets are with the 95% confidence intervals of nonlinear fittings. ED₅₀ values from gene reporter activation for melanocortin analogues on zebrafish MC4R expressed in HEK 293 cells.

^aSignificant differences (P < .05) from MC4R transfected cells.

^bSignificant differences between cells transfected with MC4R and MRAP2a treated with ACTH or ACTH + AGRP after t test (P < .05).