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Signal transduction pathways of muscarinic receptor mediated activation in the newborn and adult mouse urinary bladder.

Ekman, Mari LU ; Andersson, Karl-Erik LU and Arner, Anders LU (2009) In BJU International1999-01-01+01:00 103. p.90-97
Abstract
OBJECTIVE To study the role of M(2) and M(3) muscarinic receptor subtypes, sources of activator Ca(2+), and mechanisms involved in increased force oscillations in muscarinic contractions in the bladders of newborn and adult mice, as in the adult bladder muscarinic M(3) receptors are considered to mediate the main part of bladder contraction, and this has not been established in the newborn bladder. MATERIALS AND METHODS Bladder preparations from newborn (0-2 days) and adult (10-12 weeks) mice were mounted for in vitro force registration and activated with carbachol and high-K(+) solution in the presence of M(3) (4-DAMP 30 nm) or M(2) (methoctramine, 100 nm) receptor antagonists. Thapsigargin (1 microm) or ryanodine (10 microm) were used to... (More)
OBJECTIVE To study the role of M(2) and M(3) muscarinic receptor subtypes, sources of activator Ca(2+), and mechanisms involved in increased force oscillations in muscarinic contractions in the bladders of newborn and adult mice, as in the adult bladder muscarinic M(3) receptors are considered to mediate the main part of bladder contraction, and this has not been established in the newborn bladder. MATERIALS AND METHODS Bladder preparations from newborn (0-2 days) and adult (10-12 weeks) mice were mounted for in vitro force registration and activated with carbachol and high-K(+) solution in the presence of M(3) (4-DAMP 30 nm) or M(2) (methoctramine, 100 nm) receptor antagonists. Thapsigargin (1 microm) or ryanodine (10 microm) were used to inhibit sarcoplasmic reticulum Ca(2+) release. L-NAME (300 microm) and 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ; 10 microm) were used to inhibit nitric oxide synthase and guanylyl cyclase, respectively. Gap-junction function was inhibited with by 18-beta-glycyrrhetinic acid (18-beta-GA; 0.1-100 microm). Big-conductance (BK) and small-conductance (SK) K(+) channels were inhibited by apamine and charybdotoxin (0.3 microm), respectively. RESULTS Concentration-response relations for carbachol in the presence of 4-DAMP and methoctramine showed that M(3) receptors are the main activating pathway also in the newborn bladder. Neither thapsigargin nor ryanodine influenced the muscarinic responses of the newborn and adult bladders. Carbachol-induced contractions were not influenced by L-NAME or ODQ. The 18-beta-GA inhibited carbachol-induced contractions in both newborn and adult tissue in a similar manner. Apamine and charybdotoxin slightly increased the amplitude of the contractile responses. CONCLUSION These results suggest that in the newborn mouse bladder, as in adult bladders, the M(3) muscarinic receptor subtype is mainly responsible for carbachol-induced contractile responses. The main mechanism for muscarinic receptor-induced activation is influx of Ca(2+) from the extracellular medium, and there seems to be no major contribution of Ca(2+) release from intracellular stores. The phasic contractile activity induced by carbachol in the newborn bladder is not influenced by gap junction inhibition and does not involve SK and BK channels. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
BJU International1999-01-01+01:00
volume
103
pages
90 - 97
publisher
Blackwell Science Ltd
external identifiers
  • wos:000261683700019
  • pmid:18727613
  • scopus:57649146544
ISSN
1464-4096
DOI
10.1111/j.1464-410X.2008.07935.x
language
English
LU publication?
yes
id
24b5750c-6ca5-4769-aca5-b0e23f46b719 (old id 1222934)
alternative location
http://www.ncbi.nlm.nih.gov/pubmed/18727613?dopt=Abstract
date added to LUP
2008-09-03 12:37:38
date last changed
2017-08-13 04:33:47
@article{24b5750c-6ca5-4769-aca5-b0e23f46b719,
  abstract     = {OBJECTIVE To study the role of M(2) and M(3) muscarinic receptor subtypes, sources of activator Ca(2+), and mechanisms involved in increased force oscillations in muscarinic contractions in the bladders of newborn and adult mice, as in the adult bladder muscarinic M(3) receptors are considered to mediate the main part of bladder contraction, and this has not been established in the newborn bladder. MATERIALS AND METHODS Bladder preparations from newborn (0-2 days) and adult (10-12 weeks) mice were mounted for in vitro force registration and activated with carbachol and high-K(+) solution in the presence of M(3) (4-DAMP 30 nm) or M(2) (methoctramine, 100 nm) receptor antagonists. Thapsigargin (1 microm) or ryanodine (10 microm) were used to inhibit sarcoplasmic reticulum Ca(2+) release. L-NAME (300 microm) and 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ; 10 microm) were used to inhibit nitric oxide synthase and guanylyl cyclase, respectively. Gap-junction function was inhibited with by 18-beta-glycyrrhetinic acid (18-beta-GA; 0.1-100 microm). Big-conductance (BK) and small-conductance (SK) K(+) channels were inhibited by apamine and charybdotoxin (0.3 microm), respectively. RESULTS Concentration-response relations for carbachol in the presence of 4-DAMP and methoctramine showed that M(3) receptors are the main activating pathway also in the newborn bladder. Neither thapsigargin nor ryanodine influenced the muscarinic responses of the newborn and adult bladders. Carbachol-induced contractions were not influenced by L-NAME or ODQ. The 18-beta-GA inhibited carbachol-induced contractions in both newborn and adult tissue in a similar manner. Apamine and charybdotoxin slightly increased the amplitude of the contractile responses. CONCLUSION These results suggest that in the newborn mouse bladder, as in adult bladders, the M(3) muscarinic receptor subtype is mainly responsible for carbachol-induced contractile responses. The main mechanism for muscarinic receptor-induced activation is influx of Ca(2+) from the extracellular medium, and there seems to be no major contribution of Ca(2+) release from intracellular stores. The phasic contractile activity induced by carbachol in the newborn bladder is not influenced by gap junction inhibition and does not involve SK and BK channels.},
  author       = {Ekman, Mari and Andersson, Karl-Erik and Arner, Anders},
  issn         = {1464-4096},
  language     = {eng},
  pages        = {90--97},
  publisher    = {Blackwell Science Ltd},
  series       = {BJU International1999-01-01+01:00},
  title        = {Signal transduction pathways of muscarinic receptor mediated activation in the newborn and adult mouse urinary bladder.},
  url          = {http://dx.doi.org/10.1111/j.1464-410X.2008.07935.x},
  volume       = {103},
  year         = {2009},
}