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B1 and B2 kinin receptors mediate distinct patterns of intracellular Ca2+ signaling in single cultured vascular smooth muscle cells

Mathis, Sandra A. ; Criscimagna, Nick L. and Leeb-Lundberg, L. M Fredrik LU (1996) In Molecular Pharmacology 50(1). p.128-139
Abstract

Stimulation of B1 and B2 kinin receptors on cultured rabbit superior mesenteric artery smooth muscle cells with des-Arg9-bradykinin (DBK) and bradykinin (BK), respectively, results in significantly different patterns of intracellular Ca2+ mobilization. Single-cell fluorescence imaging of Fura- 2-loaded cells revealed that although both DBK and BK initially triggered similar rapid increases in cytosolic free Ca2+, the DBK response was biphasic and sustained, whereas the BK response was transient. The DBK response was maintained for ≤20 min with the second phase characterized by an elevated plateau and/or base-line oscillations. The BK response was limited to an initial transient peak with the exception of a few... (More)

Stimulation of B1 and B2 kinin receptors on cultured rabbit superior mesenteric artery smooth muscle cells with des-Arg9-bradykinin (DBK) and bradykinin (BK), respectively, results in significantly different patterns of intracellular Ca2+ mobilization. Single-cell fluorescence imaging of Fura- 2-loaded cells revealed that although both DBK and BK initially triggered similar rapid increases in cytosolic free Ca2+, the DBK response was biphasic and sustained, whereas the BK response was transient. The DBK response was maintained for ≤20 min with the second phase characterized by an elevated plateau and/or base-line oscillations. The BK response was limited to an initial transient peak with the exception of a few cells, which after a prolonged latency period, exhibited weak but regular base-line oscillations. The initial BK- and DBK-stimulated rises in cytosolic free Ca2+ were dependent on the release of Ca2+ from intracellular stores that seemed to be common for the two agonists. On the other hand, the continuation of the sustained phase of the DBK response required the influx of extracellular Ca2+, as well as continuous receptor occupancy by the agonist. Stimulation of cells with DBK followed by washing and restimulation with the same agonist within ≤2 min resulted in a second B1 receptor response that was not significantly different from the first response. In contrast, the same protocol with BK yielded a dramatically decreased second B2 receptor response. This attenuation did not seem to be due to a lack of Ca2+ in the agonist-sensitive intracellular stores because DBK elicited a full response after BK stimulation. This study shows that in single cultured RSMA smooth muscle cells, agonist stimulation of B1 receptors generates a sustained intracellular Ca2+ signal, whereas stimulation of B2 receptors promotes rapid and homologous desensitization, resulting in a transient Ca2+ signal. These distinct receptor-specific patterns of Ca2+ mobilization imply significantly different roles for B1 and B2 kinin receptors in vascular smooth muscle cells.

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author
publishing date
type
Contribution to journal
publication status
published
subject
in
Molecular Pharmacology
volume
50
issue
1
pages
128 - 139
publisher
American Society for Pharmacology and Experimental Therapeutics
external identifiers
  • scopus:0029893661
  • pmid:8700105
ISSN
0026-895X
language
English
LU publication?
no
id
7d0ff4c3-c103-48b4-8fab-dd59f2f61493
alternative location
http://molpharm.aspetjournals.org/content/50/1/128
date added to LUP
2019-06-10 11:13:53
date last changed
2020-01-13 01:58:51
@article{7d0ff4c3-c103-48b4-8fab-dd59f2f61493,
  abstract     = {<p>Stimulation of B1 and B2 kinin receptors on cultured rabbit superior mesenteric artery smooth muscle cells with des-Arg9-bradykinin (DBK) and bradykinin (BK), respectively, results in significantly different patterns of intracellular Ca<sup>2+</sup> mobilization. Single-cell fluorescence imaging of Fura- 2-loaded cells revealed that although both DBK and BK initially triggered similar rapid increases in cytosolic free Ca<sup>2+</sup>, the DBK response was biphasic and sustained, whereas the BK response was transient. The DBK response was maintained for ≤20 min with the second phase characterized by an elevated plateau and/or base-line oscillations. The BK response was limited to an initial transient peak with the exception of a few cells, which after a prolonged latency period, exhibited weak but regular base-line oscillations. The initial BK- and DBK-stimulated rises in cytosolic free Ca<sup>2+</sup> were dependent on the release of Ca<sup>2+</sup> from intracellular stores that seemed to be common for the two agonists. On the other hand, the continuation of the sustained phase of the DBK response required the influx of extracellular Ca<sup>2+</sup>, as well as continuous receptor occupancy by the agonist. Stimulation of cells with DBK followed by washing and restimulation with the same agonist within ≤2 min resulted in a second B1 receptor response that was not significantly different from the first response. In contrast, the same protocol with BK yielded a dramatically decreased second B2 receptor response. This attenuation did not seem to be due to a lack of Ca<sup>2+</sup> in the agonist-sensitive intracellular stores because DBK elicited a full response after BK stimulation. This study shows that in single cultured RSMA smooth muscle cells, agonist stimulation of B1 receptors generates a sustained intracellular Ca<sup>2+</sup> signal, whereas stimulation of B2 receptors promotes rapid and homologous desensitization, resulting in a transient Ca<sup>2+</sup> signal. These distinct receptor-specific patterns of Ca<sup>2+</sup> mobilization imply significantly different roles for B1 and B2 kinin receptors in vascular smooth muscle cells.</p>},
  author       = {Mathis, Sandra A. and Criscimagna, Nick L. and Leeb-Lundberg, L. M Fredrik},
  issn         = {0026-895X},
  language     = {eng},
  month        = {07},
  number       = {1},
  pages        = {128--139},
  publisher    = {American Society for Pharmacology and Experimental Therapeutics},
  series       = {Molecular Pharmacology},
  title        = {B1 and B2 kinin receptors mediate distinct patterns of intracellular Ca2+ signaling in single cultured vascular smooth muscle cells},
  url          = {http://molpharm.aspetjournals.org/content/50/1/128},
  volume       = {50},
  year         = {1996},
}