5-HT2B receptor mRNA in guinea pig superior cervical ganglion.

Primers for 5-HT2A, 5-HT2B and 5-HT2C receptor mRNAs were used in reverse transcriptase-linked polymerase chain reactions (RT-PCR) to determine the presence of these transcripts in the guinea pig superior cervical ganglion. This was done to help identify an as yet unknown 5-HT2-like receptor which, in addition to 5-HT2A receptors, mediates a slow depolarization of this preparation. PCR products corresponding to 5-HT2A and 5-HT2B, but not 5-HT2C, receptor mRNA could readily be detected. Subsequent sequence analysis of these products confirmed that the 5-HT2A band corresponded to part of the guinea pig 5-HT2A receptor and the 5-HT2B band probably represents a portion of the guinea pig 5-HT2B receptor. The latter sequence shares greater homology with an equivalent region of the human than the rat 5-HT2B receptor.