G-protein coupled receptor kinase 2 and 3 expression in human detrusor cultured smooth muscle cells

The aim of this study was to investigate the expression of G-protein couple d receptor kinases (GRKs) mRNA by RT-PCR and GRKs protein by immunohistoche mistry in human detrusor cultured smooth muscle. Primary cultures of human detrusor smooth muscle cells were established using the explant method from three normal bladders. The expression of each GRK, beta -adrenergic recept or and muscarinic acethylcholine receptor (mAchR) mRNA was examined by reve rse transcription polymerase chain reaction (RT-PCR). Immunohistochemical s taining was also performed using primary antibodies for GRKs. The GRK2 and GRK3 transcripts were detected by RT-PCR. The m2, m3 and m5 mAchR and beta1 , beta2 and beta3 adrenergic receptor subtypes mRNA were also detected. Usi ng immunohistochemistry, both GRK2 and GRK3 were found to be expressed in d etrusor smooth muscle cells. These results demonstrated the existence of GR K2 and GRK3 and the co-expression of m2, m3 and m5 mAchR and beta1, beta2 a nd beta3 adrenergic receptor subtypes in detrusor smooth muscle cells. The possibility exists that these kinases play a role in the desensitization me chanism of mAchR and beta adrenergic receptors.