Expression and pharmacological characterization of alpha(1)-adrenoceptors in rat seminal vesicle

In the present study, we investigated the alpha(1)-adrenoceptor subtypes mediating adrenaline-induced contractions of the rat seminal vesicle by using functional studies. the reverse transcription combined with polymerase chain reaction (RT-PCR) was also used to identify of alpha(1)-adrenoceptor mRNA subtypes. the rank order of potency of alpha(1)-adrenoceptor antagonists in blocking the contractile effects of adrenaline was: prazosin = WB 4101 >>> BMY 7378 > chloroethylclonidine, indicating the presence of alpha(1A)-adrenoceptors in the rat seminal vesicle. in the presence of nifedipine, there was a 76% reduction in the adrenaline-induced contractions. the nifedipine-insensitive component (24%) of the contractile response to adrenaline was unaffected by chloroethylclonidine. A small pool of spare alpha(1)-adrenoceptors for adrenaline (0.10%) was also detected. All three alpha(1)-adrenoceptor subtypes were amplified when RT-PCR was performed on total RNA isolated from rat seminal vesicle. in conclusion, these data indicate the presence of three alpha(1)-adrenoceptor mRNA subtypes, but only alpha(1A)-adrenoceptors are involved in the rat seminal vesicle contraction. (C) 1999 Elsevier Science B.V. All rights reserved.Universidade Federal de São Paulo, Escola Paulista Med, Dept Pharmacol, Expt Endocrinol Sect, BR-04044020 São Paulo, BrazilUniversidade Federal de São Paulo, Escola Paulista Med, Dept Pharmacol, Expt Endocrinol Sect, BR-04044020 São Paulo, BrazilWeb of Scienc