scholarly journals SUR2B phosphorylation by protein kinase A underscores vascular KATP channel activation by beta adrenergic receptor stimulation

2007 ◽  
Vol 21 (6) ◽  
Author(s):  
Yun Shi ◽  
Zhongying Wu ◽  
Ningren Cui ◽  
Nga Ta ◽  
Chun Jiang
Keyword(s):  
Protein Kinase ◽  
Protein Kinase A ◽  
Adrenergic Receptor ◽  
Katp Channel ◽  
Beta Adrenergic Receptor ◽  
Receptor Stimulation ◽  
Channel Activation ◽  
Beta Adrenergic ◽  
Vascular Katp Channel ◽  
Kinase A

Effects of beta-adrenergic receptor activation on alveolar macrophage cytoplasmic motility

1993 ◽  
Vol 265 (1) ◽  
pp. L67-L72 ◽  
Author(s):  
T. Fukushima ◽  
K. Sekizawa ◽  
Y. Jin ◽  
M. Yamaya ◽  
H. Sasaki ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Adrenergic Receptor ◽  
Specific Inhibitor ◽  
Lower Lobe ◽  
Receptor Activation ◽  
Maximum Effect ◽  
Inhibitory Effects ◽  
Particle Rotation ◽  
Beta Adrenergic Receptor ◽  
Beta Adrenergic

We studied the effects of fenoterol, a beta-adrenoceptor agonist, on the cytoplasmic motility of alveolar macrophages (AM) from dog lungs in vitro. Four days after the instillation of Fe3O4 particles (3 mg/kg) into the lower lobe bronchus, AM were harvested by bronchoalveolar lavage. Remanent field strength (RFS) from the AM containing Fe3O4 particles (5 x 10(6) cells) was measured immediately after magnetization. RFS decreased with time due to particle rotation (relaxation), which is related to cytoplasmic motility of AM. Fenoterol (10(-9) M to 10(-5) M) decreased the relaxation rate (lambda 0; min-1) in a concentration-dependent fashion with the maximum effect at 10(-6) M. Both forskolin (10(-6) M to 10(-4) M) and dibutyryl adenosine 3',5'-cyclic monophosphate (cAMP) (10(-3) M) mimicked fenoterol-induced inhibitory effects on lambda 0. Fenoterol and forskolin concentration-dependently increased intracellular levels of cAMP, which were parallel to decreases in lambda 0 induced by these drugs. KT 5720 (10(-5) M), a specific inhibitor of protein kinase A, significantly inhibited fenoterol (10(-6) M)-induced inhibitory effects on lambda 0 (P < 0.01). These results imply that beta-adrenergic receptor activation inhibits cytoplasmic motility of AM via increases in intracellular levels of cAMP, which may be coupled with activation of a cAMP-dependent protein kinase.

Force-frequency effect is a powerful determinant of myocardial contractility in the mouse

1997 ◽  
Vol 273 (3) ◽  
pp. H1283-H1290 ◽  
Author(s):  
V. Palakodeti ◽  
S. Oh ◽  
B. H. Oh ◽  
L. Mao ◽  
M. Hongo ◽  
...  
Keyword(s):  
Adrenergic Receptor ◽  
Myocardial Contractility ◽  
Sinus Node ◽  
Left Ventricular ◽  
Atrial Pacing ◽  
Force Frequency ◽  
Beta Adrenergic Receptor ◽  
Receptor Stimulation ◽  
Beta Adrenergic ◽  
Open Chest

The effects of heart rate (HR) on myocardial contractility in the mouse heart in situ were first investigated in open-chest mice (n = 7) by left ventricular (LV) catheter-tip micromanometry. HR was first slowed with a sinus node inhibitor (zatebradine), and atrial pacing to progressively increase the HR caused a positive inotropic response (assessed by maximum positive first derivative of LV pressure, LV dP/dtmax) up to a HR of 282 beats/min with the onset of a descending limb of the force-frequency relation (FFR) at 332 beats/min. beta-Adrenergic receptor stimulation (dobutamine) shifted upward and significantly steepened the positive FFR and increased HR at the onset of the descending limb to 402 beats/min. HR and LV dP/dtmax were then studied in closed-chest mice without pacing during recovery from anesthesia (n = 7), and during rest and intermittent physical activity the FFR was linear and positive up to 600 beats/min. HR was then progressively slowed with zatebradine, and the points at rest and during activity fell on the same linear relation. Thus we conclude the following: 1) in the open-chest anesthetized mouse, a positive FFR was amplified by beta-adrenergic receptor stimulation, and 20 in the mouse recovering from anesthesia the sinus node rate remained a critical determinant of myocardial contractility, without a descending limb of the FFR.

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