RT Journal Article T1 Mechanisms involved in testosterone-induced vasodilatation in pig prostatic small arteries A1 Navarro Dorado, Jorge A1 Orensanz Muñoz, Luis Miguel A1 Recio Visedo, María Paz A1 Bustamante Alarma, Salvador A1 Benedito Castellote, Sara A1 Martínez Gómez, Ana Cristina A1 García Sacristán, Albino A1 Prieto Ocejo, Dolores A1 Hernández Rodríguez, Medardo Vicente AB Aims: Testosterone is beneficial to the cardiovascular system due to its direct coronary vasodilatory action and its circulatory deficiency is associated with coronary artery disease (CAD), which has been proposed as an extrinsic risk factor for benign prostatic hyperplasia (BPH). Therefore, the current study investigated the mechanisms involved in the testosterone-induced vasodilatation in pig prostatic small arteries.Main methods: The testosterone vasoactive effects were assessed in small arterial rings mounted in micro- vascular myographs for isometric force recordings.Key findings: Testosterone and the non-aromatizable metabolite 4, 5α-dihydrotestosterone (DHT) evoked a similar concentration-dependent relaxation on noradrenaline (NA)-precontracted rings. Similar responses were obtained in preparations contracted with 60 mM K+-enriched physiological saline solution. Endothelium mechanical removal or pre-treatment with blockers of nitric oxide (NO) synthase, guanylate cyclase, aromatase activity, intracellular androgenic receptor (AR), 5α-reductase, prostanoid synthesis and K+ channels, failed to modify the responses to testosterone. In Ca2+-free 124 mM KPSS, testosterone markedly inhibited in a concentration-dependent manner the contraction curve t °CaCl2. In arteries pretreated with an L-type voltage-activated Ca2+ channels (VOCCs) inhibitor, nifedipine, testosterone still relaxed noradrenaline- precontracted arteries.Significance: These data suggest that testosterone induces a direct vasodilatory action in pig prostatic small arteries independent of either endothelium, NO, prostanoids, aromatase or 5α-reductase activities, AR or K+ channels. Such an effect is suggested to be produced via blockade of extracellular Ca2+ entry through L-type VOCCs and non-L-type Ca2+ channels. Testosterone-induced vasodilatation could be useful to prevent prostatic ischemia. SN 0024-3205 YR 2008 FD 2008-10 LK https://hdl.handle.net/20.500.14352/100825 UL https://hdl.handle.net/20.500.14352/100825 LA eng NO Navarro-Dorado J, Orensanz LM, Recio P, Bustamante S, Benedito S, Martínez AC, et al. Mechanisms involved in testosterone-induced vasodilatation in pig prostatic small arteries. Life Sciences 2008;83:569–73. https://doi.org/10.1016/j.lfs.2008.08.009. NO Fundación Mutua Madrileña DS Docta Complutense RD 25 ago 2024