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Effects of propofol on desipramine-sensitive [3H]-noradrenaline uptake kinetics in rat femoral artery

Sandstrom, K; Wallerstedt, S M; Tornebrandt, K and Bodelsson, Mikael LU (2000) In Acta Anaesthesiologica Scandinavica 44(8). p.1011-1016
Abstract
BACKGROUND: The intravenous anaesthetic propofol inhibits the neuronal uptake of noradrenaline (uptake1) from the vascular sympathetic neuromuscular junction, resulting in an enhancement of the sympathetic neurotransmission. This could be important for maintenance of blood pressure during propofol anaesthesia. The aim of the present study was to determine how propofol influences the kinetics of uptake1. METHODS: Isolated segments of rat femoral arteries were incubated with [3H]-noradrenaline in the presence or absence of propofol and the radioactivity taken up was measured in a scintillation counter. The uptake1 inhibitor, desipramine, was used to delineate the specific neuronal uptake. RESULTS: Desipramine and 10 microM propofol... (More)
BACKGROUND: The intravenous anaesthetic propofol inhibits the neuronal uptake of noradrenaline (uptake1) from the vascular sympathetic neuromuscular junction, resulting in an enhancement of the sympathetic neurotransmission. This could be important for maintenance of blood pressure during propofol anaesthesia. The aim of the present study was to determine how propofol influences the kinetics of uptake1. METHODS: Isolated segments of rat femoral arteries were incubated with [3H]-noradrenaline in the presence or absence of propofol and the radioactivity taken up was measured in a scintillation counter. The uptake1 inhibitor, desipramine, was used to delineate the specific neuronal uptake. RESULTS: Desipramine and 10 microM propofol significantly reduced the uptake in segments incubated with 0.1 microM [3H]-noradrenaline. Propofol at 1 microM and 100 microM did not affect the uptake. Non-linear regression analysis of specific uptake yielded Km 0.50 microM, Vmax 1.6 pmol mg(-1) 15 min(-1) and Hill coefficient 1.1. Propofol (1-10 microM) increased the Km value and propofol (10-100 microM) increased the Vmax value concentration-dependently, while the Hill coefficient was not affected. CONCLUSION: Propofol seems to have a biphasic effect on the uptake of noradrenaline in the vascular sympathetic neuromuscular junction. At lower propofol concentrations there is a decrease in the affinity of the noradrenaline transporters. The resulting uptake inhibition is counteracted at higher propofol concentrations by an increase in the efficacy of the uptake. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Propofol, femoral artery, rats, noradrenaline, sympathetic nervous system, kinetics, uptake
in
Acta Anaesthesiologica Scandinavica
volume
44
issue
8
pages
1011 - 1016
publisher
Wiley-Blackwell
external identifiers
  • pmid:10981582
  • scopus:0033851976
ISSN
0001-5172
DOI
10.1034/j.1399-6576.2000.440820.x
language
English
LU publication?
yes
id
22d7c9fc-36d0-4789-b67c-e3f73099103d (old id 1116913)
date added to LUP
2008-07-02 13:03:54
date last changed
2017-01-01 05:16:12
@article{22d7c9fc-36d0-4789-b67c-e3f73099103d,
  abstract     = {BACKGROUND: The intravenous anaesthetic propofol inhibits the neuronal uptake of noradrenaline (uptake1) from the vascular sympathetic neuromuscular junction, resulting in an enhancement of the sympathetic neurotransmission. This could be important for maintenance of blood pressure during propofol anaesthesia. The aim of the present study was to determine how propofol influences the kinetics of uptake1. METHODS: Isolated segments of rat femoral arteries were incubated with [3H]-noradrenaline in the presence or absence of propofol and the radioactivity taken up was measured in a scintillation counter. The uptake1 inhibitor, desipramine, was used to delineate the specific neuronal uptake. RESULTS: Desipramine and 10 microM propofol significantly reduced the uptake in segments incubated with 0.1 microM [3H]-noradrenaline. Propofol at 1 microM and 100 microM did not affect the uptake. Non-linear regression analysis of specific uptake yielded Km 0.50 microM, Vmax 1.6 pmol mg(-1) 15 min(-1) and Hill coefficient 1.1. Propofol (1-10 microM) increased the Km value and propofol (10-100 microM) increased the Vmax value concentration-dependently, while the Hill coefficient was not affected. CONCLUSION: Propofol seems to have a biphasic effect on the uptake of noradrenaline in the vascular sympathetic neuromuscular junction. At lower propofol concentrations there is a decrease in the affinity of the noradrenaline transporters. The resulting uptake inhibition is counteracted at higher propofol concentrations by an increase in the efficacy of the uptake.},
  author       = {Sandstrom, K and Wallerstedt, S M and Tornebrandt, K and Bodelsson, Mikael},
  issn         = {0001-5172},
  keyword      = {Propofol,femoral artery,rats,noradrenaline,sympathetic nervous system,kinetics,uptake},
  language     = {eng},
  number       = {8},
  pages        = {1011--1016},
  publisher    = {Wiley-Blackwell},
  series       = {Acta Anaesthesiologica Scandinavica},
  title        = {Effects of propofol on desipramine-sensitive [3H]-noradrenaline uptake kinetics in rat femoral artery},
  url          = {http://dx.doi.org/10.1034/j.1399-6576.2000.440820.x},
  volume       = {44},
  year         = {2000},
}