Setmelanotide (RM-493)

Kinase experiment:

Cell membranes are prepared from CHO-K1 cells stably expressing the human melanocortin receptor subtypes (MC1R, MC3R, MC4R and MC5R). They are incubated at 1-10 μg protein/well in 50 mM Tris-HCl, pH 7.4, containing 0.2% BSA, 5 mM MgCl2, 1 mM CaCl2 and 0.1 mg/mL bacitracin, with increasing concentrations of setmelanotide and 0.1-0.3 nM [125I]-NDP-α-MSH for 90-120 min at 37°C, depending on the receptor subtype. Bound from free [125I]-NDP-α-MSH is separated by filtration through GF/C glass fiber filters presoaked with 0.1 % (w/v) PEI. Filters are washed three times with 50 mM Tris-HCl, pH 7.4, at 0-4°C and assayed for radioactivity using Perkin Elmer Topcount scintillation counter[1].

Animal experiment:

Mice: Mice are weighed. Baseline blood glucose is measured and 2 g/kg body weight of D-glucose injected by i.p. BIM-22493 is administered chronically at a dose of 300 nmol/kg/day for 14 days by sc. osmotic pump. Controls are administered with 0.9% saline during the same period. Blood glucose is measured at 15, 30, 60, and 120 minutes post injection[1].

References:

[1]. Kumar KG, et al. Analysis of the therapeutic functions of novel melanocortin receptor agonists in MC3R- and MC4R-deficient C57BL/6J mice. Peptides. 2009 Oct;30(10):1892-900.
[2]. Kievit P, et al. Chronic treatment with a melanocortin-4 receptor agonist causes weight loss, reduces insulin resistance, and improves cardiovascular function in diet-induced obese rhesus macaques. Diabetes. 2013 Feb;62(2):490-7.