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Nerve induced responses and force-velocity relations of regenerated detrusor muscle after subtotal cystectomy in the rat.

Frederiksen, Hans LU ; Arner, Anders LU ; Malmquist, Ulf; Scott, Rolf Sjuve and Uvelius, Bengt LU (2004) In Neurourology and Urodynamics 23(2). p.159-165
Abstract
AIMS: To study the pharmacological and mechanical properties of newly developed detrusor muscle after subtotal cystectomy, to explore if the regenerated detrusor has characteristics similar to the normal bladder base, from which it regenerated, or to the normal bladder body which it replaces. METHODS: Partial cystectomy was performed in female rats. Fifteen weeks later, detrusor strips were cut from supratrigonal and equatorial segments. Unoperated rats served as controls. Responses to field stimulation were obtained in the absence and presence of scopolamine, prazosin, and P2X1 blockade. Dose-response curves were obtained for carbachol, alpha,beta-methylene-ATP, and phenylephrine. Force-velocity data were obtained on maximally activated... (More)
AIMS: To study the pharmacological and mechanical properties of newly developed detrusor muscle after subtotal cystectomy, to explore if the regenerated detrusor has characteristics similar to the normal bladder base, from which it regenerated, or to the normal bladder body which it replaces. METHODS: Partial cystectomy was performed in female rats. Fifteen weeks later, detrusor strips were cut from supratrigonal and equatorial segments. Unoperated rats served as controls. Responses to field stimulation were obtained in the absence and presence of scopolamine, prazosin, and P2X1 blockade. Dose-response curves were obtained for carbachol, alpha,beta-methylene-ATP, and phenylephrine. Force-velocity data were obtained on maximally activated chemically skinned preparations. RESULTS: Maximal contractile response to field stimulation was 60% of that to high-K+ with no difference between strips from control and cystectomy bladders. Prazosin had no effect. Scopolamine decreased maximal response of supratrigonal strips to 62 +/- 6 (controls) and 61 +/- 4% (operated) of that without blocker. For equatorial strips the decrease was to 81 +/- 5 (controls) and 58 +/- 8% (operated). Frequency-response relations were obtained during blockade with scopolamine, alpha,beta-methylene-ATP, and prazosin. Supratrigonal strips showed a pronounced additional inhibition up to 40 Hz. Equatorial strips from controls were completely inhibited at all frequencies. Equatorial strips from operated bladders were inhibited up to 20 Hz but not at 40 and 60 Hz. Carbachol EC(50) values were similar in all groups. Maximum response to phenylephrine was 10-20% of high-K+ response. Maximal shortening velocity (Vmax) was similar in control supratrigonal and equatorial strips, but was significantly lower in the operated bladders. CONCLUSIONS: (1): A regional difference exists in pharmacological properties of control detrusor, with a considerable contractile response to stimulation remaining in the supratrigonal muscle after simultaneous cholinergic, adrenergic, and purinergic blockade. (2): The new detrusor was functionally well innervated with no supersensitivity to muscarinic stimulation. (3): The newly formed bladder body had pharmacological properties specific for the supratrigonal segment from which it had developed. (4): There was no regional difference in force-velocity characteristics of the control detrusor. (5): The lowered Vmax in the newly formed bladder might thus be related to growth and regeneration of muscle cells. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
ATP, atropine resistance, cholinergic nerves, cystectomy, detrusor, force-velocity, Hill equation, nerve stimulation, purinergic nerves, urinary bladder
in
Neurourology and Urodynamics
volume
23
issue
2
pages
159 - 165
publisher
John Wiley & Sons
external identifiers
  • wos:000220085600015
  • pmid:14983429
  • scopus:1542363449
ISSN
0733-2467
DOI
10.1002/nau.10159
language
English
LU publication?
yes
id
3873637b-d174-4b9a-80a3-20fe37841a68 (old id 120387)
alternative location
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=14983429&dopt=Abstract
date added to LUP
2007-07-12 11:31:18
date last changed
2017-05-28 03:38:40
@article{3873637b-d174-4b9a-80a3-20fe37841a68,
  abstract     = {AIMS: To study the pharmacological and mechanical properties of newly developed detrusor muscle after subtotal cystectomy, to explore if the regenerated detrusor has characteristics similar to the normal bladder base, from which it regenerated, or to the normal bladder body which it replaces. METHODS: Partial cystectomy was performed in female rats. Fifteen weeks later, detrusor strips were cut from supratrigonal and equatorial segments. Unoperated rats served as controls. Responses to field stimulation were obtained in the absence and presence of scopolamine, prazosin, and P2X1 blockade. Dose-response curves were obtained for carbachol, alpha,beta-methylene-ATP, and phenylephrine. Force-velocity data were obtained on maximally activated chemically skinned preparations. RESULTS: Maximal contractile response to field stimulation was 60% of that to high-K+ with no difference between strips from control and cystectomy bladders. Prazosin had no effect. Scopolamine decreased maximal response of supratrigonal strips to 62 +/- 6 (controls) and 61 +/- 4% (operated) of that without blocker. For equatorial strips the decrease was to 81 +/- 5 (controls) and 58 +/- 8% (operated). Frequency-response relations were obtained during blockade with scopolamine, alpha,beta-methylene-ATP, and prazosin. Supratrigonal strips showed a pronounced additional inhibition up to 40 Hz. Equatorial strips from controls were completely inhibited at all frequencies. Equatorial strips from operated bladders were inhibited up to 20 Hz but not at 40 and 60 Hz. Carbachol EC(50) values were similar in all groups. Maximum response to phenylephrine was 10-20% of high-K+ response. Maximal shortening velocity (Vmax) was similar in control supratrigonal and equatorial strips, but was significantly lower in the operated bladders. CONCLUSIONS: (1): A regional difference exists in pharmacological properties of control detrusor, with a considerable contractile response to stimulation remaining in the supratrigonal muscle after simultaneous cholinergic, adrenergic, and purinergic blockade. (2): The new detrusor was functionally well innervated with no supersensitivity to muscarinic stimulation. (3): The newly formed bladder body had pharmacological properties specific for the supratrigonal segment from which it had developed. (4): There was no regional difference in force-velocity characteristics of the control detrusor. (5): The lowered Vmax in the newly formed bladder might thus be related to growth and regeneration of muscle cells.},
  author       = {Frederiksen, Hans and Arner, Anders and Malmquist, Ulf and Scott, Rolf Sjuve and Uvelius, Bengt},
  issn         = {0733-2467},
  keyword      = {ATP,atropine resistance,cholinergic nerves,cystectomy,detrusor,force-velocity,Hill equation,nerve stimulation,purinergic nerves,urinary bladder},
  language     = {eng},
  number       = {2},
  pages        = {159--165},
  publisher    = {John Wiley & Sons},
  series       = {Neurourology and Urodynamics},
  title        = {Nerve induced responses and force-velocity relations of regenerated detrusor muscle after subtotal cystectomy in the rat.},
  url          = {http://dx.doi.org/10.1002/nau.10159},
  volume       = {23},
  year         = {2004},
}