Kinase experiment:

Amylin binding assays are conducted by combining MK-3207 and 40 pM 125I-rat amylin, followed by 25 μg of CTR/RAMP1 or 25 μg of CTR/RAMP3 membranes and incubated for 3 h at room temperature in binding buffer (10 mM HEPES, 5 mM MgCl2, and 0.2% bovine serum albumin) in a total volume of 1 mL. Calcitonin binding assays are with 25 μg of CTR membranes and 30 pM 125I-human calcitonin as the radioligand. Incubations are terminated by filtration through GF/B 96-well filter plates that has been blocked with 0.5% polyethylenimine. Data are analyzed using Prism, and the Ki value is determined using the equation Ki=IC50/1 + ([ligand]/KD). The KD value for each receptor is determined by saturation binding experiments.

Animal experiment:

A customized flexible silicone catheter is freely suspended in the cisterna magna, anchored firmly on both sides of the atlanto-occipital membrane, and tunneled subcutaneously to the midscapular region where it is fed into a surgically implanted port body. CSF is accessed by aseptically inserting a needle through the skin and membrane covering the port into the reservoir of the port body; blood samples are collected by peripheral venipuncture. After oral administration of MK-3207 at 10 mg/kg (0.5% methylcellulose, with an adjusted pH appr 3) to cisterna magna catheter and port-implanted rhesus monkeys, CSF and plasma samples are collected at 0.5, 1, 2, 4, 8, and 24 h and analyzed for compound levels.