Figure 1. Demonstration of adenosine receptor subtypes. (A) Expression of adenosine receptor subtype mRNA in HGEC. We performed RT-PCR analysis to examine adenosine receptor mRNA of the A1, A2a, A2b, and A3 subtypes in HGEC, mononuclear leukocytes, and granulocytes. Representative results of 1 of 3 identical experiments are shown. The number of PCR cycles is shown above each lane. The mean ratios ± SD, which were determined as described in MATERIALS & METHODS, of A1, A2a, A2b, and A3 subtype expression were 2.0 ± 0.4, 13.2 ± 3.0, 8.9 ± 1.4, and 0.0 ± 0.0, respectively. (B) Examination of adenosine receptor A3 subtype mRNA expression in HGEC by nested PCR. Nested amplification primers for the A3 receptor subtype were designed within the primers for the A3 receptor. (C) Detection of adenosine receptor A3 subtype mRNA expression by nested PCR. To detect the adenosine receptor A3 subtype mRNA in HGEC, mononuclear leukocytes, and granulocytes, we performed RT-PCR for 40 cycles and then carried out re-amplification using nested primers. Results of 1 representative experiment from among 3 identical experiments are shown. The number of PCR cycles is shown above each lane.