PURPOSE: To characterize the subtypes of alpha1- and alpha2-adrenoceptors in the human corpus cavernosum from patients undergoing sex change surgery. MATERIALS AND METHODS: Saturation and competition radioligand binding studies were performed for characterization at the protein level. Alpha1-adrenoceptors were labeled with [3H]prazosin and [3H]tamsulosin, while alpha2-adrenoceptors were labeled with [3H]RX 821002. Alpha1-adrenoceptor subtype mRNA was additionally determined by reverse-transcriptase polymerase chain reaction and RNase protection assays. RESULTS: Human corpus cavernosum expressed approximately 32 and approximately 22 fmol./mg. protein alpha1- and alpha2-adrenoceptors, respectively. Competition studies with the alpha1A-selective antagonists 5-methylurapidil and (+)-niguldipine and the alpha1D-selective BMY 7378 revealed a mixed alpha1A/alpha1B-adrenoceptor population with no evidence for alpha1D-adrenoceptor protein. In contrast alpha1D-adrenoceptors were readily detected at the mRNA level. Competition binding studies with the alpha2A-selective oxymetazoline and the alpha2B-selective prazosin and ARC 239 revealed a homogeneous population of alpha2A-adrenoceptors. CONCLUSIONS: We conclude that human corpus cavernosum expresses predominantly alpha1A-, alpha1B- and alpha2A-adrenoceptor protein; additionally the alpha1D-adrenoceptor is present at the mRNA level.
PURPOSE: To characterize the subtypes of alpha1- and alpha2-adrenoceptors in the human corpus cavernosum from patients undergoing sex change surgery. MATERIALS AND METHODS: Saturation and competition radioligand binding studies were performed for characterization at the protein level. Alpha1-adrenoceptors were labeled with [3H]prazosin and [3H]tamsulosin, while alpha2-adrenoceptors were labeled with [3H]RX 821002. Alpha1-adrenoceptor subtype mRNA was additionally determined by reverse-transcriptase polymerase chain reaction and RNase protection assays. RESULTS:Human corpus cavernosum expressed approximately 32 and approximately 22 fmol./mg. protein alpha1- and alpha2-adrenoceptors, respectively. Competition studies with the alpha1A-selective antagonists 5-methylurapidil and (+)-niguldipine and the alpha1D-selective BMY 7378 revealed a mixed alpha1A/alpha1B-adrenoceptor population with no evidence for alpha1D-adrenoceptor protein. In contrast alpha1D-adrenoceptors were readily detected at the mRNA level. Competition binding studies with the alpha2A-selective oxymetazoline and the alpha2B-selective prazosin and ARC 239 revealed a homogeneous population of alpha2A-adrenoceptors. CONCLUSIONS: We conclude that human corpus cavernosum expresses predominantly alpha1A-, alpha1B- and alpha2A-adrenoceptor protein; additionally the alpha1D-adrenoceptor is present at the mRNA level.
Authors: Sol Yoon; Jae Hwi Choi; Seung Hyun Lee; See Min Choi; Seong Uk Jeh; Sung Chul Kam; Jeong Seok Hwa; Ky Hyun Chung; Jae Seog Hyun Journal: World J Mens Health Date: 2014-12-29 Impact factor: 5.400