Abstract
A new method for preparing permeabilized smooth muscle fibers from rabbit mesenteric artery has been developed using α-toxin, a transmembrane pore-making exo-protein produced by Staphylococcus aureus. After α-toxin treatment the fibers developed tension as a function of Ca2+ concentration (EC50 = 890 nM). But they could not contract without added ATP, indicating ATP is permeable. When the sarcoplasmic reticulum was loaded with 5×10-7 M Ca2+ solution, NE induced a transient contraction in 2 mM EGTA 0 M Ca2+ solution and a transient and maintained contraction in 5×10-7 M Ca2+ solution. GTP-γ-S, a non-hydrolyzable analogue of GTP, substituted for NE in producing these contractile effects. The analysis of the relationship between Ca2+ and maintained tension revealed that NE and GTP-γ-S cause increases in Ca2+ sensitivity of myofilament shifting the EC50 to 280 nM and 160 nM, respectively. We conclude that NE or GTP-γ-S causes an increase in myofilament Ca2+ sensitivity and that G protein may be involved in receptor signal transduction system. α-Toxin is a useful tool to permeabilize the smooth muscle tissue to ions and small molecules without any damage of receptor and signal transduction system.
| Original language | English |
|---|---|
| Pages (from-to) | 677-683 |
| Number of pages | 7 |
| Journal | Biochemical and Biophysical Research Communications |
| Volume | 157 |
| Issue number | 2 |
| DOIs | |
| State | Published - Dec 15 1988 |
| Externally published | Yes |
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ASJC Scopus subject areas
- Biochemistry
- Biophysics
- Molecular Biology
Cite this
Norepinephrine and GTP-γ-S increase myofilament Ca2+ sensitivity in α-toxin permeabilized arterial smooth muscle. / Nishimura, Junji; Kolber, Michael A; van Breemen, Cornelis.
In: Biochemical and Biophysical Research Communications, Vol. 157, No. 2, 15.12.1988, p. 677-683.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Norepinephrine and GTP-γ-S increase myofilament Ca2+ sensitivity in α-toxin permeabilized arterial smooth muscle
AU - Nishimura, Junji
AU - Kolber, Michael A
AU - van Breemen, Cornelis
PY - 1988/12/15
Y1 - 1988/12/15
N2 - A new method for preparing permeabilized smooth muscle fibers from rabbit mesenteric artery has been developed using α-toxin, a transmembrane pore-making exo-protein produced by Staphylococcus aureus. After α-toxin treatment the fibers developed tension as a function of Ca2+ concentration (EC50 = 890 nM). But they could not contract without added ATP, indicating ATP is permeable. When the sarcoplasmic reticulum was loaded with 5×10-7 M Ca2+ solution, NE induced a transient contraction in 2 mM EGTA 0 M Ca2+ solution and a transient and maintained contraction in 5×10-7 M Ca2+ solution. GTP-γ-S, a non-hydrolyzable analogue of GTP, substituted for NE in producing these contractile effects. The analysis of the relationship between Ca2+ and maintained tension revealed that NE and GTP-γ-S cause increases in Ca2+ sensitivity of myofilament shifting the EC50 to 280 nM and 160 nM, respectively. We conclude that NE or GTP-γ-S causes an increase in myofilament Ca2+ sensitivity and that G protein may be involved in receptor signal transduction system. α-Toxin is a useful tool to permeabilize the smooth muscle tissue to ions and small molecules without any damage of receptor and signal transduction system.
AB - A new method for preparing permeabilized smooth muscle fibers from rabbit mesenteric artery has been developed using α-toxin, a transmembrane pore-making exo-protein produced by Staphylococcus aureus. After α-toxin treatment the fibers developed tension as a function of Ca2+ concentration (EC50 = 890 nM). But they could not contract without added ATP, indicating ATP is permeable. When the sarcoplasmic reticulum was loaded with 5×10-7 M Ca2+ solution, NE induced a transient contraction in 2 mM EGTA 0 M Ca2+ solution and a transient and maintained contraction in 5×10-7 M Ca2+ solution. GTP-γ-S, a non-hydrolyzable analogue of GTP, substituted for NE in producing these contractile effects. The analysis of the relationship between Ca2+ and maintained tension revealed that NE and GTP-γ-S cause increases in Ca2+ sensitivity of myofilament shifting the EC50 to 280 nM and 160 nM, respectively. We conclude that NE or GTP-γ-S causes an increase in myofilament Ca2+ sensitivity and that G protein may be involved in receptor signal transduction system. α-Toxin is a useful tool to permeabilize the smooth muscle tissue to ions and small molecules without any damage of receptor and signal transduction system.
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UR - http://www.scopus.com/inward/citedby.url?scp=0024217418&partnerID=8YFLogxK
U2 - 10.1016/S0006-291X(88)80303-6
DO - 10.1016/S0006-291X(88)80303-6
M3 - Article
C2 - 2849434
AN - SCOPUS:0024217418
VL - 157
SP - 677
EP - 683
JO - Biochemical and Biophysical Research Communications
JF - Biochemical and Biophysical Research Communications
SN - 0006-291X
IS - 2
ER -