beta-Receptor influence on lung vasoconstrictor responses to hypoxia and humoral agents

1977 ◽  
Vol 43 (4) ◽  
pp. 612-616 ◽  
Author(s):  
R. J. Porcelli ◽  
A. T. Viau ◽  
N. E. Naftchi ◽  
E. H. Bergofsky
Keyword(s):  
Adrenergic Receptor ◽  
Adrenergic System ◽  
Hypercapnic Acidosis ◽  
Pulmonary Tissue ◽  
Beta Adrenergic ◽  
Vascular Responses ◽  
Adenosine Cyclic Monophosphate ◽  
Adrenergic Activity ◽  
Camp Levels

The role of the adrenergic receptor in mediating pulmonary vascular responses to gaseous and humoral agents was investigated by use of epinephrine injections in the perfused feline pulmonary circulation. Alteration of the balance between alpha- and beta-adrenergic activity was quantified by measurement of decreasing vasoconstrictor activity to epinephrine and rising lobar tissue 3′,5′-adenosine cyclic monophosphate (cAMP) levels. The increased beta-adrenergic activity thus generated was associated with marked reductions in the pulmonary vasoconstrictor responses to hypoxia, hypercapnic acidosis, and histamine, but not to serotonin. Repeated pulmonary vasodilations or increases in blood, but not pulmonary tissue, levels of cAMP induced by theophylline doses, which would not necessarily affect the beta-adrenergic activity, did not alter the pulmonary vasoconstrictor responses to hypoxia, hypercapnia, or histamine. These data support the significant role which the adrenergic system plays in mediating pulmonary vasoconstrictor responses to certain specific gaseous and humoral agents, and the specificity with which this mediation occurs serves to link hypoxia and histamine together so that the latter could serve as a mediator of the former.

Beta-adrenergic inhibition of electrical and mechanical activity in canine colon: role of cAMP

1993 ◽  
Vol 264 (4) ◽  
pp. G708-G717 ◽  
Author(s):  
T. K. Smith ◽  
S. M. Ward ◽  
L. Zhang ◽  
I. L. Buxton ◽  
W. T. Gerthoffer ◽  
...  
Keyword(s):  
Adrenergic Receptor ◽  
Ionic Channels ◽  
Mechanical Activity ◽  
Alpha Toxin ◽  
Contractile Apparatus ◽  
Receptor Stimulation ◽  
Beta Adrenergic ◽  
Beta 2 ◽  
Camp Levels

The effects of beta-adrenergic receptor stimulation on the electrical and mechanical activity of canine colonic circular muscles were compared with forskolin (Fsk), a known stimulator of adenylate cyclase. The actions of isoproterenol (Iso) were mediated by beta 2-receptors. Iso and Fsk increased intracellular adenosine 3',5'-cyclic monophosphate (cAMP) levels in both the presence and absence of acetylcholine (ACh), whereas ACh (0.3 microM) alone reduced cAMP levels. These agents caused inhibition of spontaneous and ACh-induced contractions. Inhibition was associated with a reduction in the amplitude and duration of electrical slow waves recorded near the submucosal border. Near the myenteric border, Iso and Fsk hyperpolarized the membrane by up to 30 mV and changed the pattern of electrical rhythmicity. These effects were mimicked by 8-bromo-cAMP (1-3 mM). Contractile inhibition with Fsk and Iso was associated with a decrease in the amplitude and duration of Ca2+ transients measured with fura-2 fluorescence. cAMP (10-300 microM) reduced the Ca2+ sensitivity of the contractile apparatus in muscles permeabilized with staphylococcal alpha-toxin. The actions of Iso appear linked to cAMP. We hypothesize that cAMP produces relaxation both by modulation of membrane ionic channels with a consequent decline in the entry of Ca2+ as well as through a decrease in the sensitivity of the contractile apparatus to Ca2+.

Alpha- and beta-adrenergic mechanisms in the control of vascular capacitance by the carotid sinus baroreflex system

1994 ◽  
Vol 267 (1) ◽  
pp. H201-H210 ◽  
Author(s):  
K. Shigemi ◽  
M. J. Brunner ◽  
A. A. Shoukas
Keyword(s):  
Adrenergic Receptor ◽  
Carotid Sinus ◽  
Venous Pressure ◽  
Systemic Circulation ◽  
Adrenergic System ◽  
Beta Adrenergic ◽  
Vascular Volume ◽  
Adrenergic Mechanisms ◽  
Vascular Capacitance ◽  
Carotid Sinus Baroreflex

We examined the active and passive contributions of the alpha- and beta-adrenergic receptor mechanisms to the changes in systemic vascular capacitance caused by the carotid sinus baroreflex system in anesthetized, vagotomized dogs. The carotid sinuses were isolated from the systemic circulation and perfused with controlled pressures. To determine the changes in vascular capacitance, a constant flow, constant venous pressure cardiopulmonary bypass was used. The changes in unstressed vascular volume were calculated when carotid sinus pressure was reduced from 200 to 50 mmHg without any adrenergic receptor antagonist, with either an alpha- (phentolamine) or a beta- (propranolol) antagonist and then with both. The reflex change in unstressed vascular volume in the systemic circulation (22.6 +/- 9.0 ml/kg without any antagonist) was reduced by 72% with phentolamine, by 35% with propranolol, and by 73% with both antagonists. Our results suggest that the alpha-adrenergic mechanisms contribute significantly to active changes in systemic venous capacity. In addition, the beta-adrenergic system has very little effect on active changes in venous vessels but does contribute to the overall capacity changes by dilating the hepatic outflow resistance when the carotid sinus baroreflex system is activated.

Role of serotonergic input in the regulation of the beta-adrenergic receptor-coupled adenylate cyclase system

Science ◽  
1982 ◽  
Vol 218 (4575) ◽  
pp. 900-901 ◽  
Author(s):  
A Janowsky ◽  
F Okada ◽  
D. Manier ◽  
C. Applegate ◽  
F Sulser ◽  
...  
Keyword(s):  
Adenylate Cyclase ◽  
Adrenergic Receptor ◽  
Adenylate Cyclase System ◽  
Beta Adrenergic Receptor ◽  
Beta Adrenergic

Role of Calcium and Beta-Adrenergic System in Control of Parathyroid Hormone Secretion

1976 ◽  
Vol 151 (2) ◽  
pp. 326-328 ◽  
Author(s):  
S. C. Kukreja ◽  
P. A. Johnson ◽  
G. Ayala ◽  
P. Banerjee ◽  
E. N. Bowser ◽  
...  
Keyword(s):  
Parathyroid Hormone ◽  
Hormone Secretion ◽  
Adrenergic System ◽  
Beta Adrenergic

P6279Mitochondria targeted catalase overexpression protects against beta-adrenergic receptor mediated cardiac remodeling in mice

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
E Uribe ◽  
D Andersson
Keyword(s):  
Oxidative Stress ◽  
Heart Failure ◽  
Adrenergic Receptor ◽  
Weight Ratio ◽  
Receptor Activation ◽  
Beta Adrenergic Receptor ◽  
Beta Adrenergic ◽  
Mitochondrial Ros ◽  
Beta Adrenergic Agonist

Abstract Background Beta-adrenergic receptor signaling is widely recognized as a fundamental component in the pathogenesis of chronic heart failure. However, the mechanisms behind beta-adrenergic receptor-mediated remodeling in cardiomyocytes and the myocardium are not fully understood. Oxidative stress has been proposed as a central pathophysiological mediator in cardiovascular disease and heart failure. The triggers and sources of oxidative stress in heart failure remain unclear. In this study we use mice with mitochondria-targeted overexpression of the antioxidant enzyme catalase (mCAT) to link beta-adrenergic receptor-mediated stress to mitochondrial reactive oxidative species (ROS) and the progression of heart failure. Hypothesis Mitochondrial ROS, induced by beta-adrenergic receptor-activation, is a mediator in the progression of the heart failure phenotype. Methods mCAT and wild type mice (n=10) were administered the non-selective beta-adrenergic agonist Isoprotenerol (Iso; 50mg/kg/day) through subcutaneous osmotic pumps for 3 weeks. Hearts were taken for biochemistry (western blotting, qPCR). Cardiomyocytes were isolated and loaded with Fluo-3 AM to study intracellular Ca2+ transients and fractional shortening using confocal line scan microscopy. All experiments were performed in accordance with the Stockholm ethical committee for animal research. Results and conclusions The WT mice displayed an increased heart/body weight ratio following chronic Iso administration. In contrast, mCAT mice displayed resistance to Iso-induced cardiac hypertrophy (p<0.05). Furthermore, chronic Iso exposure in WT mice induced increased ROS-dependent post-translational protein modifications, impaired cardiomyocyte Ca2+ handling and reduced contractility in isolated cardiomyocytes (p<0.05). Cardiomyocytes from mCAT mice did not display the deleterious effects of chronic Iso exposure on cardiomyocyte Ca2+ and contractility. Our study demonstrates that beta-adrenergic receptor stimulation-induced remodeling of the heart, which is similar to what is seen in heart failure, can be prevented by overexpressing catalase in the mitochondria. This indicates an important role of mitochondrial ROS in the link between adrenergic signaling and the development of cardiomyopathy and heart failure. Acknowledgement/Funding Hjärtlungfonden

Sign in / Sign up

Export Citation Format

Share Document