Cloning and cerebral expression of the guinea pig histamine H-3 receptor: evidence for two isoforms

We cloned the full length guinea pig H-3 receptor cDNA using RT-PCR amplifi cation with primers from the human receptor and templates from brain areas. Evidence was obtained for two isoforms, designated H3L and H3S, differing by a 30 amino acid stretch within the third cytosolic loop, presumably gene rated by alternative splicing. In situ hybridization using a selective cRNA probe showed the gene transcripts to be highly expressed in discrete neuro nal populations, e.g. pyramidal cells in the cerebral cortex or cerebellar Purkinje cells, in some instances already known to express other histamine receptor subtypes. NeuroReport 11:755-759 (C) 2000 Lippincott Williams & Wi lkins.