Adrenergic Agent

2020 ◽  
Author(s):  
Keyword(s):  
1992 ◽  
Vol 263 (5) ◽  
pp. C1049-C1056 ◽  
Author(s):  
K. Anwer ◽  
L. Toro ◽  
C. Oberti ◽  
E. Stefani ◽  
B. M. Sanborn

The properties of Ca(2+)-activated K+ currents and channels were characterized in pregnant rat myometrium in whole cell and cell-attached patches and in lipid bilayers. Membrane depolarization of cultured myometrial cells from a holding potential of -50 to +70 mV in 10-mV steps under voltage-clamp conditions (whole cell mode) activated K+ outward currents (IK). At +70 mV, in the presence of 0.2 mM external Ca2+, the amplitude and activation time constant of IK were 15.0 +/- 2.1 microA/microF and 1.5 +/- 0.2 ms, respectively. Addition of 1 microM A23187 to the external solution increased the current from a control value of 16.0 +/- 2.0 to 67.9 +/- 9.1 microA/microF. Charybdotoxin, a blocker of Ca(2+)-activated K (KCa) channels, and a low concentration of tetraethylammonium chloride (TEA; 1 mM) decreased the amplitude of IK by 47 and 62%, respectively. In cell-attached patches from these cells, 1 microM A23187 increased the open time probability of a 143 +/- 6.0 pS K+ channel. Incorporation of plasma membrane vesicles from pregnant myometrium into lipid bilayers resulted in one predominant type of K+ channel. The unitary conductance of the K+ channel was 326 +/- 9.0 pS in symmetrical 450 mM KCl. The channel activation was both voltage and Ca2+ dependent. TEA inhibited the channel activity with a dissociation constant (Kd) of 378 +/- 10 microM at -60 mV or 1,477 +/- 80 microM at +60 mV. The whole cell currents were found to be stimulated by isoproterenol, a beta-adrenergic agent.(ABSTRACT TRUNCATED AT 250 WORDS)


CHEST Journal ◽  
1989 ◽  
Vol 96 (6) ◽  
pp. 1233-1236 ◽  
Author(s):  
Jean-Louis Vincent ◽  
Charles Reuse ◽  
Robert J. Kahn

1978 ◽  
Vol 234 (2) ◽  
pp. E106 ◽  
Author(s):  
F Okajima ◽  
M Ui

Insulin secretory responses via adrenergic mechanisms were studied in vivo with hyperthyroid rats prepared by daily injections with thyroxine and with rats rendered hypothyroid by the addition of methylthiouracil in the drinking water. Isoproterenol, a beta-adrenergic agent, caused hyperinsulinemia in hyperthyroid rats more markedly than in euthyroid rats, but failed to induce hyperinsulinemia in hypothyroid rats. The isoproterenol-induced hyperinsulinemia was abolished by a beta-adrenergic receptor blocker in hyperthyroid as well as in euthyroid rats. The glucose-induced hyperinsulinemia was enhanced in hyperthyroid, was not essentially affected in euthyroid, and was inhibited in hypothyroid rats, by an alpha- and beta-adrenergic agent such as epinephrine. It is concluded that the relative function of alpha- to beta-adrenergic receptors responsible for the pancreatic secretion of insulin is dependent on the thyroid state; beta-adrenergic actions are predominant over alpha-actions in hyperthyroidism and vice versa in hypothyroidism.


1973 ◽  
Vol 117 (8) ◽  
pp. 1067-1075 ◽  
Author(s):  
Henk C.S. Wallenburg ◽  
Julius Mazer ◽  
Donald L. Hutchinson

Life Sciences ◽  
1982 ◽  
Vol 30 (20) ◽  
pp. 1757-1762 ◽  
Author(s):  
Judith Huerta-Bahena ◽  
Rafael Villalobos-Molina ◽  
J.Adolfo García-Sáinz
Keyword(s):  

1978 ◽  
Vol 1 (1) ◽  
pp. 3-12 ◽  
Author(s):  
Susumu Iwasa ◽  
Koichi Kondo ◽  
Tsutomu Miya ◽  
Kazumi Takeda

ChemInform ◽  
2010 ◽  
Vol 29 (30) ◽  
pp. no-no
Author(s):  
R. SENGUPTA ◽  
R. BANERJEE ◽  
J. K. DATTAGUPTA
Keyword(s):  

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