Expression of 5-HT2A and 5-HT1B receptor mRNA in blood vessels.
Expression of two subtypes of 5-hydroxytryptamine (5-HT) receptors, 5-HT1B and 5-HT2A, was investigated in normal rat arteries (abdominal aorta) and veins (inferior vena cava) by the quantitative reverse transcription-polymerase chain reaction (RT-PCR). The arterial 5-HT2A receptor mRNA level in artery was 25-fold (p < 0.01) higher than the venous level, and the arterial 5-HT1B receptor mRNA level was at least 7000-fold (p < 0.005) higher the venous level.