Effects of excitatory neurotransmitters on Ca2+ channel current in smooth muscle cells isolated from guinea‐pig urinary bladder

@article{Nakayama1993EffectsOE,
  title={Effects of excitatory neurotransmitters on Ca2+ channel current in smooth muscle cells isolated from guinea‐pig urinary bladder},
  author={Shinsuke Nakayama},
  journal={British Journal of Pharmacology},
  year={1993},
  volume={110}
}
  • S. Nakayama
  • Published 1993
  • Chemistry, Medicine
  • British Journal of Pharmacology
1 A whole‐cell voltage clamp technique was used to examine the effects of purinoceptor and muscarinic receptor agonists on voltage‐sensitive Ca2+ channels in guinea‐pig isolated urinary bladder cells. 2 When the cell membrane was clamped at the holding potential, rapid application of ATP elicited a large inward current in normal solution containing 2.5 mm Ca2+, and reduced the subsequent Ca2+ channel current evoked by a depolarizing pulse (0 mV). Carbachol (CCh) elicited little membrane current… Expand
Long Ca2+ channel opening induced by large depolarization and Bay K 8644 in smooth muscle cells isolated from guinea‐pig detrusor
TLDR
It is concluded that L‐type Ca2+ channels in guinea‐pig detrusor cells are open for much longer after large depolarizations consistent with their being two channel open states, and that Bay K 8644 prolongs the lifetime of both open states. Expand
Ca(2+) channel properties in smooth muscle cells of the urinary bladder from pig and human.
TLDR
The pig is forward as a good model for the human in detrusor Ca(2+) channel properties, especially with regard to neural modulation, although voltage-sensitive Ca( 2+) channels seem to make greater contribution in human bladder physiology. Expand
Muscarinic suppression of Ca2+ current in smooth muscle cells of the guinea‐pig urinary bladder
TLDR
It appears that CCh suppresses ICa via two independent mechanisms: (1) Ca(2+)‐mediated inactivation of the Ca2+ channel, which is caused byCa2+ release from InsP3‐ and TG‐sensitive internal stores, and (2) a GTP‐binding protein‐mediated mechanism, which requires intracellular Ca2+. Expand
Involvement of ryanodine receptors in muscarinic receptor-mediated membrane current oscillation in urinary bladder smooth muscle.
TLDR
The fact that distinct mechanisms underlie the two types of inward current may help in development of clinical treatments of, for example, urinary incontinence and residual urine volume control. Expand
The α1‐subunit of smooth muscle Ca2+ channel preserves multiple open states induced by depolarization
1 The cloned α1‐subunits of the smooth muscle Ca2+ channel (α1C‐b) from rabbit lung were expressed in Chinese hamster ovary cells. The effect of large depolarizations was examined using cell‐attachedExpand
Possible contribution of long open state to noninactivating Ca2+ current in detrusor cells.
TLDR
Differences in the voltage dependence of the development of the long open state in various smooth muscles, as well as differences in the equilibrium constant between open and inactivated states, could underlie the different patterns of contractile behavior that characterize smooth muscles. Expand
Ca2+ mobilization and activation of extracellular acidification by carbachol in acutely dispersed cells from guinea pig detrusor: Fura 2 fluorometry and microphysiometry using the cytosensor.
TLDR
Cell suspensions such as these may prove to be simple tools for the pharmacological study of urinary bladder smooth muscle tissue and indicate the dominant role of M3 receptors in guinea-pig bladder but fail to show clear evidence of any functional role for M2 receptors. Expand
Slow deactivation and U-shaped inactivation properties in cloned Cav1.2b channels in Chinese hamster ovary cells.
TLDR
A kinetic scheme with one closed state, two open states (O(1, O(2)) and two inactivated states linked to the closed state and open state O(1), respectively, protected from inactivation is drawn up, suggesting involvement of physical processes in the channel protein. Expand
Electrical and mechanical responses produced by nerve stimulation in detrusor smooth muscle of the guinea-pig.
TLDR
In smooth muscles of the guinea-pig bladder, intramural nerve stimulation generated an excitatory junctional potential, action potential and twitch contraction, and it is concluded that nerve stimulation releases acetylcholine and ATP, and the former produces contraction without change in the membrane potential, while the latter generates the e.j.p. which triggers anaction potential and thus elicits contractions. Expand
The effect of anoxia and glucose-free solutions on the contractile response of guinea-pig detrusor strips to intrinsic nerve stimulation and the application of excitatory agonists.
TLDR
The results demonstrate that phasic contractions can be fuelled almost fully by oxidative phosphorylation or by anaerobic glycolysis, but that in conditions mimicking ischaemia the intrinsic nerves are more susceptible to ischaemic damage than the detrusor smooth muscle. Expand
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The results suggest that the voltage‐dependent Ca2+ channels have at least two open states with different time constants, the tail current being the result of a long open channel state induced by large depolarizations. Expand
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The actions of exogenously applied ATP were investigated with the whole‐cell patch clamp method in single cells isolated from guinea‐pig urinary bladder with a modified concentration jump technique to find the possible role of ATP as the fast excitatory transmitter. Expand
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