THREE alpha1 adrenergic receptor subtypes have been identified by molecular cloning techniques. However, the detection of the mRNA for the alpha1C subtype has not yet been reported in rodent tissues. We have isolated from rat lung, by polymerase chain reaction techniques, a cDNA fragment corresponding to the third intracellular domain of the alpha1C adrenergic receptor subtype. The nucleotide and deduced amino acid sequences of the cloned fragment presented an 87% and 96% identity, respectively, with those from the bovine receptor. Analysis of the distribution of the receptor mRNA in brain shows highest expression levels in cerebellum and striatum, whereas in non-neural tissues the receptor is mainly expressed in lung and heart. It was also found that the gene sequence which codes for this domain is not interrupted by introns.
