Neurovascular Role of Sympathetic Nervous System and Beta-Adrenoceptor Polymorphisms in Obesity and Hypertension

2008 ◽  
Vol 4 (2) ◽  
pp. 121-130 ◽  
Author(s):  
Kazuko Masuo ◽  
Gavin Lambert ◽  
Hiromi Rakugi ◽  
Toshio Ogihara ◽  
Murray Esler
1988 ◽  
Vol 255 (5) ◽  
pp. E617-E620 ◽  
Author(s):  
M. M. Jepson ◽  
D. J. Millward ◽  
N. J. Rothwell ◽  
M. J. Stock

The object of this study was to assess the role of brown adipose tissue (BAT) and the sympathetic nervous system in the rise in heat production associated with endotoxin-induced fever. Oxygen consumption (VO2) was found to be significantly increased (28%) over a 4-h period after two doses of endotoxin (Escherichia coli lipopolysaccharide, 0.3 mg/100 g body wt) given 24 h apart. Injection of a mixed beta-adrenoceptor antagonist (propranolol) reduced VO2 by 14% in endotoxin-treated rats, whereas the selective beta 1- (atenolol) or beta 2- (ICI 118551) antagonists suppressed VO2 by 10%. These drugs did not affect VO2 in control animals. BAT thermogenic activity assessed from measurements of in vitro mitochondrial guanosine 5'-diphosphate (GDP) binding was elevated by 54% in interscapular BAT and by 171% in other BAT depots. Surgical denervation of one lobe of the interscapular depot prevented these responses. Endotoxin failed to stimulate GDP binding in rats fed protein-deficient diets. This may have been because BAT thermogenic activity was already elevated in control rats fed these diets or because endotoxin caused a marked suppression of food intake in the protein-deficient animals. The results indicate that sympathetic activation of BAT is involved in the thermogenic responses to endotoxin and that these can be modified by dietary manipulation.


1981 ◽  
Vol 97 (1) ◽  
pp. 91-97 ◽  
Author(s):  
H. Storm ◽  
C. van Hardeveld ◽  
A. A. H. Kassenaar

Abstract. Basal plasma levels for adrenalin (A), noradrenalin (NA), l-triiodothyronine (T3), and l-thyroxine (T4) were determined in rats with a chronically inserted catheter. The experiments described in this report were started 3 days after the surgical procedure when T3 and T4 levels had returned to normal. Basal levels for the catecholamines were reached already 4 h after the operation. The T3/T4 ratio in plasma was significantly increased after 3, 7, and 14 days in rats kept at 4°C and the same holds for the iodide in the 24-h urine after 7 and 14 days at 4°C. The venous NA plasma concentration was increased 6- to 12-fold during the same period of exposure to cold, whereas the A concentration remained at the basal level. During infusion of NA at 23°C the T3/T4 ratio in plasma was significantly increased after 7 days compared to pair-fed controls, and the same holds for the iodide excretion in the 24-h urine. This paper presents further evidence for a role of the sympathetic nervous system on T4 metabolism in rats at resting conditions.


2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
Costas Tsioufis ◽  
Athanasios Kordalis ◽  
Dimitris Flessas ◽  
Ioannis Anastasopoulos ◽  
Dimitris Tsiachris ◽  
...  

Resistant hypertension (RH) is a powerful risk factor for cardiovascular morbidity and mortality. Among the characteristics of patients with RH, obesity, obstructive sleep apnea, and aldosterone excess are covering a great area of the mosaic of RH phenotype. Increased sympathetic nervous system (SNS) activity is present in all these underlying conditions, supporting its crucial role in the pathophysiology of antihypertensive treatment resistance. Current clinical and experimental knowledge points towards an impact of several factors on SNS activation, namely, insulin resistance, adipokines, endothelial dysfunction, cyclic intermittent hypoxaemia, aldosterone effects on central nervous system, chemoreceptors, and baroreceptors dysregulation. The further investigation and understanding of the mechanisms leading to SNS activation could reveal novel therapeutic targets and expand our treatment options in the challenging management of RH.


Hypertension ◽  
1999 ◽  
Vol 34 (1) ◽  
pp. 102-106 ◽  
Author(s):  
Mario J. Carvalho ◽  
Anton H. van den Meiracker ◽  
Frans Boomsma ◽  
Joao Freitas ◽  
Arie J. Man in ‘t Veld ◽  
...  

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