Animal experiment:

Mice[1]Female BALB/c mice are used between 8 and 10 weeks of age. SCH563705 or MK-0812 are administered in a 0.4% methylcellulose (MC) solution by 30 mg/kg oral gavage (p.o.). Two hours later, the frequency of CD11b+Ly6G-Ly6Chi monocytes and CD11b+Ly6G+Ly6C+ neutrophils is determined by flow cytometry[1].

MK-0812 Succinate is a potent and selective CCR2 antagonist with high affinity at CCR2. CCR2

MK-0812 is a potent and selective CCR2 antagonist[1]. MK-0812 completely blocks all MCP-1 mediated response in a concentration dependent manner, with an IC50 of 3.2 nM. This value is similar to the potency observed for the inhibition of 125I-MCP-1 binding by MK-0812 on isolated monocytes (IC50 4.5 nM). In fact, MK-0812 not only completely blocks the shape change response to exogenous MCP-1, but also results in a monocyte forward scatter measurement below unstimulated or basal levels. The addition of MK-0812 to rhesus blood also inhibits MCP-1 induced monocyte shape change. The IC50 for MK-0812 in whole blood assays is 8 nM[2]

MK-0812 (30 mg/kg, p.o.) reduces the frequency of Ly6G-Ly6Chi monocytes in the peripheral blood, while no impact on circulating Ly6G+Ly6C+ neutrophil frequency is observed. In addition, MK-0812 treatment causes a dose-dependent reduction in circulating Ly6Chi monocytes and a corresponding elevation in the CCR2 ligand CCL2[1]. MK-0812 is administered by continuous i.v. infusion to maintain a constant level of the drug in blood[2].

[1]. Min SH, et al. Pharmacological targeting reveals distinct roles for CXCR2/CXCR1 and CCR2 in a mouse model of arthritis.Biochem Biophys Res Commun. 2010 Jan 1;391(1):1080-6. [2]. Wisniewski T, et al. Assessment of chemokine receptor function on monocytes in whole blood: In vitro and ex vivo evaluations of a CCR2 antagonist.J Immunol Methods. 2010 Jan 31;352(1-2):101-10.