caa a22 4500 475742699 CHVBK 20180406123504.0 cr unu---uuuuu 170329e20000801xx s 000 0 eng 10.1007/s002400000109 doi (NATIONALLICENCE)springer-10.1007/s002400000109 The role of intracellular and extracellular calcium in mechanical and intracellular electrical activity of human urinary bladder smooth muscle [Elektronische Daten] [A. J. Visser, R. van Mastrigt] We studied the role of extracellular and intracellular Ca2+ in human detrusor smooth muscle contraction. Simultaneous recordings of mechanical and intracellular electrical activity were made in three different Ca2+ concentrations: normal Krebs' solution (100%), 10% of the standard Ca2+ concentration and a solution in which Ca2+ was omitted from the medium (0%). Spontaneous contractions and KCl or CCh induced contractions were studied. Ryanodine and caffeine were used to manipulate the intracellular Ca2+ stores. The present results show that only a very small amount of Ca2+ in the extracellular space is sufficient to support spontaneous and induced contractions. Spike-shaped potentials and long lasting depolarisations were recorded in all three solutions. However, the prevalence of long lasting depolarisations increased when the extracellular Ca2+ concentration was reduced. The amplitude of the spike-shaped potentials and long lasting depolarisations appeared to be negatively affected by diminishing the extracellular Ca2+ concentration. Additionally, the duration of the long lasting depolarisations was reduced in 0% Ca2+. The contraction upon KCl stimulation was primarily depending on the extracellular Ca2+. Upon muscarinic receptor stimulation, a combined activation of Ca2+ mobilisation from intracellular and extracellular stores may occur; the ratio of contribution of these two sources changes in accordance with the requirements of the conditions. Springer-Verlag Berlin Heidelberg, 2000 Key words Detrusor nationallicence Force nationallicence Electrophysiology nationallicence Action potential nationallicence Visser A. J. Department of Urology-Urodynamics, Room EE 1630, Erasmus University Rotterdam, PO box 1738, 3000 DR Rotterdam, The Netherlands e-mail: visser@udn.fgg.eur.nl Tel.: +31 10 408 7377; Fax: +31 10 408 9451, NL aut van Mastrigt R. Department of Urology-Urodynamics, Room EE 1630, Erasmus University Rotterdam, PO box 1738, 3000 DR Rotterdam, The Netherlands e-mail: visser@udn.fgg.eur.nl Tel.: +31 10 408 7377; Fax: +31 10 408 9451, NL aut https://doi.org/10.1007/s002400000109 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s002400000109 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Visser A. J. Department of Urology-Urodynamics, Room EE 1630, Erasmus University Rotterdam, PO box 1738, 3000 DR Rotterdam, The Netherlands e-mail: visser@udn.fgg.eur.nl Tel.: +31 10 408 7377; Fax: +31 10 408 9451, NL aut NATIONALLICENCE 700 1- van Mastrigt R. Department of Urology-Urodynamics, Room EE 1630, Erasmus University Rotterdam, PO box 1738, 3000 DR Rotterdam, The Netherlands e-mail: visser@udn.fgg.eur.nl Tel.: +31 10 408 7377; Fax: +31 10 408 9451, NL aut Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer