Using reverse transcription and a competitive polymerase chain reaction for quantification of alpha1B-adrenoceptor...

Molecular cloning studies have revealed the existence of three subtypes of alpha1-adrenergic receptor (alpha1-AR), namely alpha1A, alpha1B and alpha1D. They are encoded by separate genes and have distinct pharmacological profiles. In rats' brain, the expression of mRNA for subtypes of an alpha1-AR is partially structure-dependent. Our previous studies employing Northern blot analysis of mRNA have shown that in the hippocampus, where alpha1A predominates, the alpha1B receptor (alpha1B-AR) was almost undetectable. The goal of the present study was to establish the method of reverse transcription and competitive polymerase chain reaction (RT-cPCR) to quantify a steady state level of alpha1B-AR mRNA in the hippocampus, prefrontal cortex and thalamus, and to compare the alpha1B-AR' pattern of expression with that revealed by Northern blot analysis. Our results have shown that alpha1B-AR is similarly represented in the thalamus and prefrontal cortex. In the hippocampus, ten times lower expression of alpha1B mRNA has been demonstrated with RT-cPCR, which was below a detection limit of Northern blot hybridization technique.