receptor mRNA levels are regulated in response to inflammatory injury. A) Amplification of DRG cDNA by conventional RT-PCR using the P2YGi real-time PCR primers produced a single band for each receptor of the expected size (100-150 bp). B) Real-time PCR was used to analyze mRNA levels for each of the Gi-coupled P2Y receptors and the Gq-coupled P2Y1 at 1, 4 and 15 days after induction of inflammatory hyperalgesia by injection of complete Freund's adjuvant into the hindpaw. The shaded box indicates the period of significant heat hyperalgesia determined using the Hargreaves test. Data are normalized against baseline values. *p < 0.01, ‡p < 0.05, For PCR, n = 5 mice/time point. For behavior, n = 10 mice/time point.