LOCALIZATION OF P-2Y1 PURINOCEPTOR TRANSCRIPTS IN THE RAT PENIS AND URINARY-BLADDER

Purpose: The aim of this study was to determine the expression and loc alization of the P2Y(1) purinoceptor mRNA in rat penis and urinary bla dder using reverse transcription polymerase chain reaction (RT-PCR), n orthern blotting and in situ hybridization (ISH). Materials and Method s: RT-PCR: First strand cDNA was prepared from rat penis and urinary b ladder dome total RNA and used for PCR with primers designed to amplif y fragments of the P2Y(1) purinoceptor cDNA sequence. Northern blottin g: PCR products were subcloned into the pGEM-5Zf(+) plasmid vector, se quenced and random primer labeled using P-32. Labeled probe was hybrid ized, ISH: Digoxigenin labeled cRNA probes were synthesized by in vitr o transcription, Results: P2Y1 purinoceptor mRNA was detected by RT-PC R analysis in both rat penis and urinary bladder. RNA blotting using a P2Y(1) purinoceptor cDNA probe revealed a single transcript of 4.2kb in both tissues. This band was the same size as that expressed by the heart, which contains high levels of P2Y(1) purinoceptor (Burnstock, G ,: Physiological and pathological roles of purines: an update. Drug. D ev. Res., 28: 195, 1993). By ISH, P2Y(1) purinoceptor mRNA was localiz ed in detrusor smooth muscle cells and blood vessels in urinary bladde r. In penis, positive signals were detected in endothelial cells which line the lacunar space and blood vessels. No hybridization was seen i n corpus cavernosum smooth muscle cells and urethra. Conclusion: These results indicate that mRNAs for P2Y(1) purinoceptor are expressed in detrusor smooth muscle cells and blood vessels of rat urinary bladder. However, in penis, this receptor is expressed in endothelial cells wh ich lines the lacunar space and blood vessels, but not expressed in co rpus cavernosum smooth muscle cells and urethra.