Effects of androgen manipulation on α1-adrenoceptor subtypes in the rat seminal vesicle

• DOI: 10.1016/j.lfs.2004.03.011
• Publication Date: 2004-06-17T13:06:22Z
• Authors: Fúlvio R Mendes; Margarete Hamamura; Daniel B.C Queiróz; Catarina S Porto; Maria Christina W...
• Keywords: Male; 0301 basic medicine; Analysis of Variance; Barium Compounds; Organ Size; Clonidine; Piperazines; Rats; Dioxanes; Phenylephrine; 03 medical and health sciences; Chlorides; Gene Expression Regulation; Quinoxalines; Adrenergic alpha-1 Receptor Antagonists; Androgens; Quinazolines; Animals; Autoradiography; RNA, Messenger; Cyproterone Acetate; Orchiectomy

This study analyses possible changes during surgical and chemical castration in the expression and pharmacological characteristics of alpha1-adrenoceptor in adult rat seminal vesicle. Ribonuclease protection assays indicated that alpha1a--was the predominant mRNA, while alpha1b-and alpha1d-adrenoceptor transcripts were detected in lower abundance in this tissue. alpha1a-adrenoceptor mRNA expression presented a complex dependency on androgens, while alpha1b- and alpha1d-adrenoceptor transcripts were both upregulated with surgical and chemical castration, suggesting a negative modulation by androgens. Testosterone treatment reversed the effects caused by surgical castration. Functional studies confirmed the involvement of alpha1A- and alpha1B-adrenoceptor in the seminal vesicle contractile responses, and suggested that alpha1B-induced contractile response was upregulated after castration. Taken together, the results suggest that alpha1-adrenoceptor expression in seminal vesicle is differentially regulated by the androgen status of the rat.