Expression of 5 genes involved in GLP-1 incretin biology in different rat tissues assessed by quantitative Taqman PCR. Two biologically different samples were analyzed and averaged (shown are mean values and SD). The geometric mean of three housekeeping genes (GAPDH, Actb and B2M) was used to normalize expression of specific genes using the formula 2^-Δc(t). For detection of GLP1R two different specific Taqman primer assays were used spanning different part of the receptor mRNA. GLP1R (P1) denotes Rn00562406_m1 and detect exon 3–4. GLP1R (P2) is the label for Rn01640381_m1 which detects a sequence spanning exon 8–9. The term n.a. indicates that no specific amplification could be achieved at the maximum cycle number (n=40).