Identification, Quantification, and Localization of mRNA for Three Distinct Alpha1 Adrenergic Receptor Subtypes in Human Prostate
The dynamic component of bladder outlet obstruction caused by benign prostatic hyperplasia (BPH) is regulated by alpha1 adrenergic receptors (α1-AR) located in the prostatic stroma. Recently two α1-AR subtypes (α1A, α1B) have been identified in the human prostate by both functional and pharmacological assays. However, the presence of the α1C subtype has not been evaluated, presumably due to the lack of availability of selective ligands for this receptor subtype. We have used molecular techniques to investigate the mRNA expression of all three α1-AR subtypes in the human prostate. RNA extracted from the prostate gland of 15 patients was used in ribonuclease protection assays to identify the expression of three α1-AR subtype mRNAs. Quantitative solution hybridization assays further identify the predominant subtype of α1-AR mRNA to be the α1C, which represents approximately 70% of the total α1-AR mRNA in the human prostate. Furthermore, in situ hybridization localizes the α1C AR mRNA predominantly to the stromal compartment. The identification of a predominant α1-AR mRNA in human prostate identifies a potential need for subtype selective pharmaceutical agents. These agents could be very important clinically in the treatment of diseases such as BPH.