Loss of Diurnal Rhythms of Blood Pressure and Heart Rate Caused by High-Fat Feeding

Carroll, Joan F.; Thaden, Jeremy J.; Wright, Allison M.; Strange, Taylor

doi:10.1016/j.amjhyper.2005.04.018

Cited by 18 publications

(18 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…20 Accordingly, decrease of heart rate and BP variability or nondipping status in obese subjects might be caused by overactivity of the sympathetic nervous system. Consistent with the report by Carroll et al, 21 which shows high fat feeding in rabbits caused immediate losses of diurnal rhythms of BP and heart rate that were independent of weight gain and BP elevation, there are some reports that show an increase of whole day mean arterial pressure and heart rate, rapid abolition the normal diurnal rhythm of mean arterial pressure and heart rate, and increase of low-frequency energy of systolic BP variabilities were shown at an early but not at a late phase after an hyperlipidic and hypercaloric diet. 22,23 Another study also reported that a high fat diet induces abdominal obesity, hyperinsulinaemia, and arterial hypertension, with a left ventricular hypertrophy associated with a biphasic change in autonomic activity.…”

supporting

confidence: 83%

Loss of Diurnal Rhythms of Blood Pressure and Heart Rate Due to High Fat Feeding

Kaneda

Kario

2005

American Journal of Hypertension

View full text Add to dashboard Cite

Obesity is the most prevalent nutritional disorder in developed countries 1 and plays an important role in cardiovascular morbidity through multiple mechanisms, 2 including well-known risk factors such as hypertension, diabetes, and dyslipidemia. [3][4][5][6][7][8] Previous studies have shown that being overweight is associated with increased cardiac output 9 and resting heart rate, with decreased heart rate variability, 10 and with increased prevalence of nondipping status, 11 which is considered to be prognostic indicators of cardiovascular mortality 12,13 and morbidity 14,15 in humans. Sympathetic nervous system activity is increased in patients with essential hypertension per se, 16 and the adrenergic factors represent one of the mechanisms involved in determining blood pressure (BP) variability 17 including the nondipping pattern of BP. We have the data that diurnal BP variation in elderly hypertensive individuals was significantly associated with neurohumoral factors regulating circulating blood volume. Nondippers appeared to have ␣-and ␤-adrenergic subsensitivity, which may be induced by their chronic exposure to high norepinephrine levels. 18On the other hand, overactivity of the sympathetic nervous system is a common feature of obesity in humans and in animal models. Study of regional sympathetic nerve activity in obese humans using norepinephrine spillover has demonstrated that obesity is associated with increased sympathetic activity to the kidney, a key organ of cardiovascular homeostasis.19 Chronic hyperinsulinemia is also associated with a high output, low resistance hemodynamic state, persistent baroreflex downregulation, and episodic (postprandial) sympathetic dominance.20 Accordingly, decrease of heart rate and BP variability or nondipping status in obese subjects might be caused by overactivity of the sympathetic nervous system. Consistent with the report by Carroll et al, 21 which shows high fat feeding in rabbits caused immediate losses of diurnal rhythms of BP and heart rate that were independent of weight gain and BP elevation, there are some reports that show an increase of whole day mean arterial pressure and heart rate, rapid abolition the normal diurnal rhythm of mean arterial pressure and heart rate, and increase of low-frequency energy of systolic BP variabilities were shown at an early but not at a late phase after an hyperlipidic and hypercaloric diet. 22,23 Another study also reported that a high fat diet induces abdominal obesity, hyperinsulinaemia, and arterial hypertension, with a left ventricular hypertrophy associated with a biphasic change in autonomic activity. This biphasic change consists of an early and long-lasting decrease in parasympathetic nervous system activity and an early but transient increase in sympathetic activity. 10 The autonomic nervous system changes are dependent on the time course of obesity development. Therefore, the importance of immediate sympathetic nerve activation with overfeeding is clear. However, it is indispensable to investigate the associati...

show abstract

supporting

confidence: 83%

Loss of Diurnal Rhythms of Blood Pressure and Heart Rate Due to High Fat Feeding

Kaneda

Kario

2005

American Journal of Hypertension

View full text Add to dashboard Cite

show abstract

“…In the present study, Sprague-Dawley rats were fed with HD feed formulation in order to establish the HD model. The HD lead to changes in lipid metabolism, including increased levels of serum TC, TG and LDL, and a decreased HDL level, which is a major risk factor for cardiovascular disease such as arterial injury (21). Effects of aerobic exercise on high cholesterol metabolism have been investigated for numerous years, although they have certain differences in the results due to the different sport modes, intensity, research subjects and methods (33), a large number of clinical studies have found that long-term regular aerobic exercise can effectively improve the poor structure so that the risk of cardiovascular disease is significantly reduced (34).…”

Section: Discussionmentioning

confidence: 99%

“…Together, these two parameters were observed in the exercised rats and indicated that the intermittent exercise groups achieved a good level of fitness. Obesity is a significant risk factor for cardiovascular events (2,3,6-8), it not only causes aortic injury in rats fed with a HD, but it also lowers the antioxidant enzyme activity in the body and leads to lipid metabolism disorder (21)(22)(23).…”

Section: Discussionmentioning

confidence: 99%

Intermittent exercise improves the vasoreactivity of the thoracic aorta in rats

Luo

et al. 2016

Biomedical Reports

View full text Add to dashboard Cite

Abstract. Vasoreactivity is the most basic and direct indicator to reflect the artery vascular functional state in the body. The majority of previous studies have shown that a high-fat diet (HD) is often associated with a variety of cardiovascular diseases. However, the type of exercise that improves vasoreactivity, as is induced by a HD, remains to be elucidated. In the present study, the effects of aerobic moderate-intensity intermittent exercise through swimming were investigated on thoracic aorta vascular ring contraction and free radical metabolism using Sprague-Dawley rat models of common diet (CD; 23 g protein, 49 g carbohydrate, 4 g fat, 5 g fiber, 7 g bone meal and 6 g vitamins per 100 g), HD (peanuts, milk chocolate and sweet biscuits, in a weight ratio of 3:2:2:1), CD with intermittent exercise (CIE) and HD with intermittent exercise (HIE). The food utilization rate in the swimming group (CIE) decreased in comparison with the CD group. Lee's index in the CIE group decreased in comparison to that of CD after 8 weeks (P<0.05) and also HIE decreased compared to HD (P<0.05) after 8 weeks. Compared with the HD group, contractile response of the thoracic aortic rings to NA decreased in the HIE group, while high-density lipoprotein cholesterol content increased, total cholesterol, triglycerides and low-density lipoprotein cholesterol decreased (P<0.05); the malondialdehyde (MDA) concentration reduced in the myocardium, but the superoxide dismutase (SOD) level improved (P<0.05). In the HIE group, nitric oxide level was similar to the CD group. Compared with CD, contractile response of the thoracic aortic rings to NA increased in the CIE (P<0.05), the MDA concentration reduced in the myocardium, but the SOD level improved (P<0.05). Tunica media smooth muscle of the thoracic aortic rings in the CIE group arranged more regularly in comparison with the CD group (without swimming training). In conclusion, intermittent exercise improves the thoracic aorta vasoreactivity and function by enhanced antioxidant enzyme activity and reduced free radical generating. IntroductionAs living standards improve, high-fat diet-induced obesity has become a common phenomenon (1). Obesity is often associated with a variety of diseases, such as atherosclerosis, hyperlipidemia, hypertension, diabetes and cardiovascular diseases (2-10). Vasoreactivity is the most basic and direct indicator of reflecting artery vascular function state, which has become an important indicator of cardiovascular disease (11). Studies have found that a high-fat diet (HD) and lack of exercise training are the most important factors in the development of obesity. Therefore, exercise training can control obesity and cardiovascular disease, and it has become a research focus. However, the exercise intensity, duration and different diets will produce different effects on metabolic activity (12). Long-term aerobic exercise could markedly improve the abnormal hemorheological property and the oxidative stress in rats with hypercholesterolemia (13). Inadequate nutri...

show abstract

“…Implantable telemetry has been widely used for measuring blood pressure in mice, rats and rabbits for both acute and chronic purposes 13,[18][19][20] and has consequently become an alternative technique to catheterization. More recently, new surgical techniques have been developed for measuring pressure within the left ventricle in rabbits.…”

Section: Discussionmentioning

confidence: 99%

“…All the rabbits were housed one per cage (surface: 0.36 m 2 ) under controlled conditions: room temperature of [18][19][20][21] C, 12 h/12 h light-dark cycle, with free access to water, standard rabbit chow once a day and dry grass once a week. The study protocol was approved by the Institutional Ethics Committee of KU Leuven.…”

Section: Animalsmentioning

confidence: 99%

Measurement of right ventricular pressure by telemetry in conscious moving rabbits

2013

View full text Add to dashboard Cite

Implantable radiotelemetry methodology has been used to continuously monitor pulmonary hemodynamics including right ventricular pressure (RVP) or pulmonary arterial pressure (PAP) in conscious, untethered and freely moving animals such as mice and rats. The use of implantable radiotelemetry to monitor RVP or PAP has never previously been described in rabbits. The aim of the present study was to use implantable radiotelemetry to continuously monitor RVP in conscious adult rabbits. Telemetry transmitters were implanted in 44 adult male New Zealand rabbits using a trans-diaphragm approach for the catheter placement. RVP, heart rate (HR) and activity were monitored every 15 min for 20 s. Body mass was recorded once a week. A total of 39 (88%) rabbits were successfully implanted. Thirty rabbits survived the surgical procedure resulting in an overall survival rate of 73%. RVP, HR and activity were long-term monitored in 17 rabbits for an average period of 103 AE 15 days. Weekly body mass follow-up showed that implantable radiotelemetry did not impair the normal development of the animal. Twenty-four-hour period monitoring of RVP, HR and activity showed concomitant changes in RVP, HR and activity according to the dark/light cycle applied to the rabbits. To conclude, implantable radiotelemetry methodology can be safely used to continuously monitor RVP in conscious rabbits. KeywordsTelemetry, right ventricular pressure, pulmonary circulation, rabbit Pulmonary hypertension is a medical condition mainly affecting the pulmonary circulation. Various rodent animal models have been developed to better understand the physiopathology of pulmonary hypertension and to test potential new drugs.1 Hemodynamic data from these animal models are usually restricted to a single measurement of pulmonary arterial pressure (PAP) and/or right ventricular pressure (RVP), in anesthetized, mechanically ventilated and often openchest animals.2,3 More recently, high-resolution echocardiography and magnetic resonance imaging (MRI) techniques have been developed to accurately estimate hemodynamics in small animals including rats, mice and rabbits, and to allow for serial monitoring of experimental pulmonary hypertension.4,5 Although these techniques are non-invasive, they are performed on anesthetized animals, which implies respiratory and cardiovascular depression resulting in various artifacts. Continuous monitoring of RVP and PAP in conscious, untethered and freely moving animals was introduced by Hess et al. in the 1990s and has consequently and considerably improved hemodynamic pulmonary measurement in rodent models of pulmonary hypertension. 6 Since then, telemetry has been widely described as a method for measuring RVP and PAP in rodent models of pulmonary hypertension.7-10 However, the original procedure of implantable radiotelemetry methodology included extremely invasive thoracic surgery resulting in significant stress, potentially disturbing the cardiovascular system, and in delayed recovery. More recently, a trans-diaphragm surgi...

show abstract

Loss of Diurnal Rhythms of Blood Pressure and Heart Rate Caused by High-Fat Feeding

Abstract: In this study ad libitum high-fat feeding in rabbits caused immediate losses of diurnal rhythms of BP and HR that were independent of weight gain and BP elevation.

Cited by 18 publications

References 25 publications

Loss of Diurnal Rhythms of Blood Pressure and Heart Rate Due to High Fat Feeding

Loss of Diurnal Rhythms of Blood Pressure and Heart Rate Due to High Fat Feeding

Intermittent exercise improves the vasoreactivity of the thoracic aorta in rats

Measurement of right ventricular pressure by telemetry in conscious moving rabbits

Contact Info

Product

Resources

About