OBJECTIVES: This study sought to further elucidate the regulation of cavernous smooth muscle tone and to characterize mechanisms of cavernous activation and relaxation. METHODS: In isolated strips of rabbit corpus cavernosum, extracellular electrical and mechanical activity were recorded simultaneously before and after pharmacologic stimulation. RESULTS: Spontaneous mechanical activity was characterized by fast phasic contractions (frequency 6 to 30 min-1) associated with fluctuations of the extracellular electrical signals. Phasic activity was increased by blockade of potassium channels or by moderate activation of L-type calcium channels. Faster spikelike fluctuations occurred in the electrical activity, indicating the existence of spike discharges. All mechanical and electrical fluctuations were completely abolished by blockade of L-type calcium channels with nifedipine. CONCLUSIONS: Our results indicate that cavernous smooth muscle tone is regulated by both phasic and tonic activation mechanisms caused by the opening of L-type calcium channels and calcium influx through chemically controlled calcium influx/release.
OBJECTIVES: This study sought to further elucidate the regulation of cavernous smooth muscle tone and to characterize mechanisms of cavernous activation and relaxation. METHODS: In isolated strips of rabbit corpus cavernosum, extracellular electrical and mechanical activity were recorded simultaneously before and after pharmacologic stimulation. RESULTS: Spontaneous mechanical activity was characterized by fast phasic contractions (frequency 6 to 30 min-1) associated with fluctuations of the extracellular electrical signals. Phasic activity was increased by blockade of potassium channels or by moderate activation of L-type calcium channels. Faster spikelike fluctuations occurred in the electrical activity, indicating the existence of spike discharges. All mechanical and electrical fluctuations were completely abolished by blockade of L-type calcium channels with nifedipine. CONCLUSIONS: Our results indicate that cavernous smooth muscle tone is regulated by both phasic and tonic activation mechanisms caused by the opening of L-type calcium channels and calcium influx through chemically controlled calcium influx/release.
Authors: A S Leitão Junior; R M Campos; J B G Cerqueira; M C Fonteles; C F Santos; G de Nucci; E H S Sousa; L G F Lopes; L F Gonzaga-Silva; N R F Nascimento Journal: Int J Impot Res Date: 2015-10-29 Impact factor: 2.896
Authors: Anderson Fellyp Avelino Diniz; Iara Leão Luna de Souza; Elba Dos Santos Ferreira; Maria Thaynan de Lima Carvalho; Bárbara Cavalcanti Barros; Paula Benvindo Ferreira; Maria da Conceição Correia Silva; Francisco Fernandes Lacerda Júnior; Lydiane de Lima Tavares Toscano; Alexandre Sérgio Silva; Fabiana de Andrade Cavalcante; Bagnólia Araújo da Silva Journal: Oxid Med Cell Longev Date: 2020-06-30 Impact factor: 6.543