Effects of polyamines on voltage-activated calcium channels in guinea-pig intestinal smooth muscle
Gomez, Maria LU
and Hellstrand, Per
LU
(1995)
In Pflügers Archiv
430(4).
p.501-507
- Abstract
- Effects of polyamines on the spontaneous mechanical and electrical activity of guinea-pig intestinal smooth muscle were studied. Spermine and spermidine inhibited action potential generation and contractions, while putrescine had no effect. Single smooth muscle cells were isolated from the longitudinal muscle layer of the guinea-pig ileum. Whole-cell voltage-clamp experiments were carried out to investigate the effects of polyamines on current through voltage-activated Ca2+ channels. Spermine and spermidine (0.1-1 mM) reduced the inward current in a concentration-dependent manner. Spermine blocked current activated by the dihydropyridine agonist BAY K 8644 (1 microM), whereas no additional inhibition by spermine was seen after blockage of... (More)
- Effects of polyamines on the spontaneous mechanical and electrical activity of guinea-pig intestinal smooth muscle were studied. Spermine and spermidine inhibited action potential generation and contractions, while putrescine had no effect. Single smooth muscle cells were isolated from the longitudinal muscle layer of the guinea-pig ileum. Whole-cell voltage-clamp experiments were carried out to investigate the effects of polyamines on current through voltage-activated Ca2+ channels. Spermine and spermidine (0.1-1 mM) reduced the inward current in a concentration-dependent manner. Spermine blocked current activated by the dihydropyridine agonist BAY K 8644 (1 microM), whereas no additional inhibition by spermine was seen after blockage of dihydropyridine-sensitive channels by nifedipine (0.1 microM). Inhibition by spermine or spermidine did not shift the peak of the current voltage relation of the inward current. Steady-state activation and inactivation relationships were not affected and thus the amplitude, but not the voltage dependence, of the window current responsible for Ca2+ inflow during sustained depolarization was affected. Putrescine (1 mM) had no significant effect on the inward current. These results suggest that spermine and spermidine inhibit contraction in spontaneously active intestinal smooth muscle by inhibiting Ca2+ current responsible for generation of action potentials. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/1108868
- author
- Gomez, Maria
LU
and Hellstrand, Per
LU
- organization
- publishing date
- 1995
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- Intestinal smooth muscle, Whole-cell voltage clamp, Ca2+ channels, Polyamines, Spermine, Spermidine, Putrescine
- in
- Pflügers Archiv
- volume
- 430
- issue
- 4
- pages
- 501 - 507
- publisher
- Springer
- external identifiers
-
- pmid:7491276
- scopus:0029051791
- ISSN
- 0031-6768
- DOI
- 10.1007/BF00373886
- language
- English
- LU publication?
- yes
- id
- 6d5e8d62-ee2f-4161-9237-e3a26b98e2c6 (old id 1108868)
- date added to LUP
- 2016-04-01 16:53:49
- date last changed
- 2021-01-03 06:08:25
@article{6d5e8d62-ee2f-4161-9237-e3a26b98e2c6,
abstract = {{Effects of polyamines on the spontaneous mechanical and electrical activity of guinea-pig intestinal smooth muscle were studied. Spermine and spermidine inhibited action potential generation and contractions, while putrescine had no effect. Single smooth muscle cells were isolated from the longitudinal muscle layer of the guinea-pig ileum. Whole-cell voltage-clamp experiments were carried out to investigate the effects of polyamines on current through voltage-activated Ca2+ channels. Spermine and spermidine (0.1-1 mM) reduced the inward current in a concentration-dependent manner. Spermine blocked current activated by the dihydropyridine agonist BAY K 8644 (1 microM), whereas no additional inhibition by spermine was seen after blockage of dihydropyridine-sensitive channels by nifedipine (0.1 microM). Inhibition by spermine or spermidine did not shift the peak of the current voltage relation of the inward current. Steady-state activation and inactivation relationships were not affected and thus the amplitude, but not the voltage dependence, of the window current responsible for Ca2+ inflow during sustained depolarization was affected. Putrescine (1 mM) had no significant effect on the inward current. These results suggest that spermine and spermidine inhibit contraction in spontaneously active intestinal smooth muscle by inhibiting Ca2+ current responsible for generation of action potentials.}},
author = {{Gomez, Maria and Hellstrand, Per}},
issn = {{0031-6768}},
keywords = {{Intestinal smooth muscle; Whole-cell voltage clamp; Ca2+ channels; Polyamines; Spermine; Spermidine; Putrescine}},
language = {{eng}},
number = {{4}},
pages = {{501--507}},
publisher = {{Springer}},
series = {{Pflügers Archiv}},
title = {{Effects of polyamines on voltage-activated calcium channels in guinea-pig intestinal smooth muscle}},
url = {{http://dx.doi.org/10.1007/BF00373886}},
doi = {{10.1007/BF00373886}},
volume = {{430}},
year = {{1995}},
}