Ex vivo analysis of A3AR expression level in paw and PBMCs from AIA rats. (a, b) MTX treatment induced expression of A3AR mRNA and protein, and CF101 treatment resulted in receptor downregulation. (c) This was reflected in the PBMCs. (d) Expression of A2AAR was also induced in paw extracts derived AIA rats treated with MTX. A3AR, A3 adenosine receptor; AIA, adjuvant-induced arthritis; MTX, methotrexate; PBMC, peripheral blood mononuclear cell.