Selective reduction of neurotransmitter release by cAMP-dependent pathways in mouse detrusor
File(s)ajpregu.00166.2022.pdf (1.67 MB)
Published version
Author(s)
Chakrabarty, Basu
Drake, Marcus J
Kanai, Anthony J
Fry, Christopher H
Type
Journal Article
Abstract
Parasympathetic nerve-mediated contractions of detrusor smooth muscle are generated by ATP and ACh release from efferent nerve terminals. In humans, ACh is responsible for detrusor contractions in normal human bladders, whereas ATP has an additional role in overactive bladder pathologies. The ATP metabolite, adenosine, relaxes nerve-mediated contractions, with a potential action via presynaptic adenosine A1 receptor activation and subsequent suppression of neuronal ATP release. We investigated the effect of A1 receptor activation and downstream cAMP-dependent pathways on nerve-mediated ATP and ACh release, and detrusor contraction in mouse detrusor. Bladders from male C57BL/6 mice (12 weeks) were used. Upon electrical field stimulation of intact preparations (detrusor and mucosal layers), ATP or ACh release was measured simultaneously with tension recordings. Activation of A1 receptors by adenosine or exogenous agonists reduced the lower frequency component of nerve-mediated contractions, and neuronal ATP release. The A1 receptor antagonist abolished these effects. A1 receptor activation inhibits AC activity and cAMP generation. The effect of A1 receptor activation was mimicked by a PKA antagonist, but not by modulators of exchange proteins activated by cAMP, demonstrating that modulation of nerve-mediated ATP release is via PKA. Adenosine had no effect on ACh release or the higher frequency component of nerve-mediated contractions. Differential regulation of neurotransmitter release is possible at the detrusor nerve-muscle junction, as demonstrated by A1 receptor activation, and downstream inhibition of AC, cAMP generation and PKA. The ability to specifically attenuate ATP release offers a potential to target purinergic motor pathways enhanced in overactive bladder pathologies.
Date Issued
2022-12-01
Date Acceptance
2022-10-11
Citation
AJP - Regulatory, Integrative and Comparative Physiology, 2022, 323, pp.R889-R899
ISSN
0363-6119
Publisher
American Physiological Society
Start Page
R889
End Page
R899
Journal / Book Title
AJP - Regulatory, Integrative and Comparative Physiology
Volume
323
Copyright Statement
© 2022 The Authors.
Licensed under Creative Commons Attribution CC-BY 4.0. Published by the American Physiological Society.
Licensed under Creative Commons Attribution CC-BY 4.0. Published by the American Physiological Society.
License URL
Notes
Funding Information: Funding was provided by the National Institutes of Health Grant NIH R01 DK098361 (to A. J. Kanai, M. J. Drake, and C. H. Fry). Publisher Copyright: Copyright © 2022 the American Physiological Society. keywords: adenosine, Adenosine Triphosphate, cyclic AMP, detrusor smooth muscle, Neurotransmitter
Publication Status
Published
Article Number
6
Date Publish Online
2022-11-21