Abstract
Binding studies with (-)-[125I]cyanopindolol (ICYP) were conducted to characterize β-adrenoceptors in plantaris and soleus muscles of rats (male, 250-300 g). The distribution of β1- and β2-adrenoceptors in different muscle fiber types, identified in serial sections by succinic dehydrogenase (SDH) staining, was studied by autoradiography. The densities of binding sites (Bmax, mol/mg protein) were 5.4 ± 0.9 (mean ± SEM) in plantaris and 11.5 ± 2.0 in soleus muscle. In plantaris muscle, monophasic competition curves were observed when binding experiments were performed using CGP 20712A (50 pM to O.SmM), a β1-adrenoceptor selective antagonist, or ICI 118,551 (50 pM to 20,μM), a β2-adrenoceptor selective antagonist, to compete for ICYP binding. Analysis with LIGAND revealed a single binding site with a KD value of 2.41 ± 0.56 nM (mean ± SEM) for ICI 118,551 and 8.93 ± 3.00 μM for CGP 20712A, indicating the presence of a homogeneous population of β2-adrenoceptors. In soleus muscle, competition curves were biphasic with 16-21% β1-adrenoceptors. Autoradiographic studies supported the findings from binding studies with membrane homogenates. The ICYP binding pattern was associated closely with the muscle fiber types identified by SDH staining. Propranolol-resistant binding sites were observed, and these sites were associated with muscle fibers positive to SDH staining.
| Original language | English |
|---|---|
| Pages (from-to) | 1783-1789 |
| Number of pages | 7 |
| Journal | Biochemical Pharmacology |
| Volume | 42 |
| Issue number | 9 |
| DOIs | |
| Publication status | Published - 9 Oct 1991 |
Cite this
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Characterization of β1- and β2-adrenoceptors in rat skeletal muscles. / Kim, Yong S.; Sainz, Roberto D.; Molenaar, Peter; Summers, Roger J.
In: Biochemical Pharmacology, Vol. 42, No. 9, 09.10.1991, p. 1783-1789.Research output: Contribution to journal › Article › Research › peer-review
TY - JOUR
T1 - Characterization of β1- and β2-adrenoceptors in rat skeletal muscles
AU - Kim, Yong S.
AU - Sainz, Roberto D.
AU - Molenaar, Peter
AU - Summers, Roger J.
PY - 1991/10/9
Y1 - 1991/10/9
N2 - Binding studies with (-)-[125I]cyanopindolol (ICYP) were conducted to characterize β-adrenoceptors in plantaris and soleus muscles of rats (male, 250-300 g). The distribution of β1- and β2-adrenoceptors in different muscle fiber types, identified in serial sections by succinic dehydrogenase (SDH) staining, was studied by autoradiography. The densities of binding sites (Bmax, mol/mg protein) were 5.4 ± 0.9 (mean ± SEM) in plantaris and 11.5 ± 2.0 in soleus muscle. In plantaris muscle, monophasic competition curves were observed when binding experiments were performed using CGP 20712A (50 pM to O.SmM), a β1-adrenoceptor selective antagonist, or ICI 118,551 (50 pM to 20,μM), a β2-adrenoceptor selective antagonist, to compete for ICYP binding. Analysis with LIGAND revealed a single binding site with a KD value of 2.41 ± 0.56 nM (mean ± SEM) for ICI 118,551 and 8.93 ± 3.00 μM for CGP 20712A, indicating the presence of a homogeneous population of β2-adrenoceptors. In soleus muscle, competition curves were biphasic with 16-21% β1-adrenoceptors. Autoradiographic studies supported the findings from binding studies with membrane homogenates. The ICYP binding pattern was associated closely with the muscle fiber types identified by SDH staining. Propranolol-resistant binding sites were observed, and these sites were associated with muscle fibers positive to SDH staining.
AB - Binding studies with (-)-[125I]cyanopindolol (ICYP) were conducted to characterize β-adrenoceptors in plantaris and soleus muscles of rats (male, 250-300 g). The distribution of β1- and β2-adrenoceptors in different muscle fiber types, identified in serial sections by succinic dehydrogenase (SDH) staining, was studied by autoradiography. The densities of binding sites (Bmax, mol/mg protein) were 5.4 ± 0.9 (mean ± SEM) in plantaris and 11.5 ± 2.0 in soleus muscle. In plantaris muscle, monophasic competition curves were observed when binding experiments were performed using CGP 20712A (50 pM to O.SmM), a β1-adrenoceptor selective antagonist, or ICI 118,551 (50 pM to 20,μM), a β2-adrenoceptor selective antagonist, to compete for ICYP binding. Analysis with LIGAND revealed a single binding site with a KD value of 2.41 ± 0.56 nM (mean ± SEM) for ICI 118,551 and 8.93 ± 3.00 μM for CGP 20712A, indicating the presence of a homogeneous population of β2-adrenoceptors. In soleus muscle, competition curves were biphasic with 16-21% β1-adrenoceptors. Autoradiographic studies supported the findings from binding studies with membrane homogenates. The ICYP binding pattern was associated closely with the muscle fiber types identified by SDH staining. Propranolol-resistant binding sites were observed, and these sites were associated with muscle fibers positive to SDH staining.
UR - http://www.scopus.com/inward/record.url?scp=0026043995&partnerID=8YFLogxK
U2 - 10.1016/0006-2952(91)90516-8
DO - 10.1016/0006-2952(91)90516-8
M3 - Article
VL - 42
SP - 1783
EP - 1789
JO - Biochemical Pharmacology
JF - Biochemical Pharmacology
SN - 0006-2952
IS - 9
ER -