PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Parasympathetic Nervous System”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 163 records · Page 9Linked to original sources
PubMed1996

Role of the parasympathetic autonomic nervous system in digitalis intoxication: electrocardiographic and histological study.

The role of the parasympathetic autonomic nervous system (ANS) in digoxin intoxication was investigated in atropine pretreated conscious rabbits. Both the electrocardiographic registration and the histologic analysis indicated possible prevention of lethal arrhythmias by atropine pretreatment. The hearts of animals pretreated with atropine appeared less damaged, since they presented only a light cytoplasmic vacuolization. It was evident that the administration of digoxin without atropine pretreatment provoked dramatic signs of digitalis intoxication followed by animal death. Myocardia of these rabbits were highly damaged. On the other hand, our experimental data indicated that the abolishment of the vagal tone by atropine blockade caused only signs (i.e. inversion of the T wave) due to myocardial ischemia, to which the light cytoplasmic vacuolation could be correlated. Myocardial ischemia could be caused by constriction of coronary blood vessels, which could be consequential to both the prevalent activity of the orthosympathetic ANS, following parasympathetic blockade, and direct digoxin effects on vascular fibrecells, which both produce vasoconstriction. Therefore, it is reasonable to assume that the parasympathetic ANS plays a major role in digitalis intoxication in rabbits.

Animals↗
PubMed2002

Effects of nicardipine and diltiazem on fractal features of short-term heart rate variability--application of coarse graining spectral analysis.

PURPOSE: This study was designed to investigate the effects of nicardipine and diltiazem on the fractal features of short-term heart rate variability (HRV), using coarse graining spectral analysis (CGSA). METHODS: Eighteen healthy volunteers participated in this study; they were divided into two groups according to the drug administered. Five-minute electrocardiogram and arterial pressure recordings were made during stepwise infusions of either nicardipine (0.4, 0.8, 1.6, and 3.2 microg.kg(-1).min(-1)) or diltiazem (2, 4, 8, and 16 microg.kg(-1).min(-1)) under rate-controlled breathing at 0.25 Hz. CGSA broke down the total power of the time series into harmonic (low frequency [0.0-0.15 Hz; LF] and high frequency [0.15-0.5 Hz; HF]) and nonharmonic (fractal) components. Cardiac sympathetic nervous system (SNS) and parasympathetic nervous system (PNS) activity indicators were evaluated as the ratios LF/HF and HF/TP (total spectral power), respectively. Fractal components were evaluated as %fractal and the spectral exponent beta of 1/f(beta). RESULTS: Compared with control measurements, the maximum dose of nicardipine infusion caused a significant decrease in systolic arterial pressure, a significant increase in the mean heart rate, and a significant increase in plasma norepinephrine level, findings that were associated with significant increases in %fractal and beta values (54.2 +/- 13.3 vs 75.6 +/- 9.8, and 0.86 +/- 0.22 vs 1.32 +/- 0.46, respectively; P < 0.05). PNS and SNS indicators showed decreased and increased values, respectively. Diltiazem caused a reduction in arterial pressure; however, no other parameters, including the nonharmonic components of HRV, were affected by this drug. CONCLUSIONS: These findings strongly suggest that nicardipine suppresses vagal cardiac neural outflow and activate the SNS, an action which, subsequently, causes changes in the fractal features of HRV. Although diltiazem reduces arterial pressure, it preserves the basic neural balance of the autonomic nervous system in regard to heart rate control.

Journal Article↗
PubMed1991

Vasodilator responses following intracranial stimulation of the trigeminal, facial and glossopharyngeal nerves in the cat gingiva.

The effects of electrical stimulation of the trigeminal, facial and glossopharyngeal nerves on gingival blood flow in the cat were studied. The intracranial part of these nerves was stimulated electrically, and gingival blood flow was measured by the laser Doppler technique. Electrical stimulation of the trigeminal, facial and glossopharyngeal nerves caused blood flow to increase in the ipsilateral gingiva both with the cranial nerve intact and after cutting it to the medulla. Stimulation of the distal cut ends of the facial and glossopharyngeal nerves elicited an increase in blood flow but no increase in systemic blood pressure. Pretreatment with hexamethonium reduced the increase in blood flow elicited by electrical stimulation of the facial and glossopharyngeal nerves, but had no effect on that elicited by stimulation of the trigeminal nerve. In contrast, pretreatment with tripelennamine attenuated the trigeminal nerve-stimulated blood flow increase, but not that elicited by stimulation of the facial and glossopharyngeal nerves. Atropine, propranolol and phentolamine had no effect on these responses. These results suggest that the autonomic nervous system, particularly the parasympathetic nervous system, is responsible for the blood flow increase elicited by facial and glossopharyngeal nerve stimulation, and that the trigeminal nerve-stimulated blood flow increase is induced by antidromic vasodilatation of the trigeminal sensory nerve.

Animals↗
PubMedDate not supplied

Fast detoxification of heroin addicts by acupuncture and electrical stimulation (AES) in combination with naloxone.

Detoxification can be accomplished more rapidly by first "flushing" the opiates from the receptor sites. Naloxone, a short acting antagonist displaces opiates from the receptor sites and such displacement precipitates an abstinence syndrome. Recently, a method of using acupuncture and electrical stimulation (AES) in combination with naloxone for fast detoxification was reported. This technique was applied to 50 cases of heroin addicts. Forty-one were detoxified. There were nine failures. Of the 41 cases, 18 patients were sent to rehabilitation centres and did not experience abstinence symptoms. Six were sent out of Hong Kong where heroin is not available, and two others did not go to a rehabilitation centre but still abstained. The other 15 were presumed to be on the drug. It is advocated that AES increases endorphin and relieves abstinence syndrome, but also at the same time inhibits the autonomic nervous system, mainly the parasympathetic nervous system. The technique does not stop the craving, therefore after detoxification, the patients should be sent for psycho-social rehabilitation, or alternatively be put on long acting antagonist.

Acupuncture Therapy↗
PubMed1994

Influence of atrial natriuretic factor on heart rate variability in normal men.

To study the effects of atrial natriuretic factor (ANF) on sympathetic nervous system (SNS) and parasympathetic nervous system (PNS) control of heart rate, we gave ANF (50 micrograms over 3 min, then 50 ng.kg-1.min-1) and saline (vehicle) to six normal men [age 22 +/- 2 (SE) yr] during supine rest on two separate study days according to a random double-blind design. R-R interval data were sampled at 1,000 Hz over 7-min time segments, then analyzed by coarse graining spectral analysis of heart rate variability (HRV) to yield indicators of PNS and SNS activity. From the harmonic component of HRV, the integrated power in the low-frequency region (0.0-0.15 Hz, PL) and in the high-frequency region (0.15-0.50 Hz, PH) were calculated. Total spectral power (PT) was obtained and used to normalize the PNS indicator as PH/PT. The quantity PL/PH was taken as an indicator of SNS activity. By the 20th min of its infusion, ANF lowered PT, PH, and the SNS indicator (4.20 +/- 1.9 to 2.37 +/- 0.65; P < 0.05) but did not significantly change the PNS indicator (PH/PT). In contrast, 20-min saline infusion had no effect on these variables. These observations are consistent with our previous documentation of a relative sympathoinhibitory action of ANF on muscle sympathetic nerve activity and support the concept that ANF acts on the autonomic nervous system to decrease sympathetic outflow.

Adult↗
PubMed1997

Differential responsivity of monocyte cytokine and adhesion proteins in high- and low-hostile humans.

This study tested the general hypothesis that high- and low-hostile respondents would show different patterns of change in monocyte cytokine and adhesion protein (MCAP) expression in response to pharmacologically induced alterations in sympathetic nervous system (SNS) and parasympathetic nervous system (PNS) balance. On 3 separate days, 4 high- and 4 low-hostile respondents received isoproterenol infusions after saline, atropine (PNS blockade), or neostigmine (PNS stimulation) pre-treatment. Dual color flow cytometry with fluorescently labeled monoclonal antibodies to CD 14 (monocyte market), interleukin-1, leukocyte function activator (LFA-1), Class II major histocompatibility complex (MHC-II), and tumor necrosis factor was used to quantify cytokine and adhesion protein expression on monocytes in blood samples drawn before and after the combination drug infusions on the 3 test days in each respondents. Following PNS stimulation and istoproterenol infusion there was a decrease (compared to saline pretreatment) in MHC II expression in high hostiles that was significantly (p<.02) different from an increase in low hostiles. A similar trend (p = .08) was seen for LFA-1 expression, with high hostiles showing an increase and low hostiles a decrease. These findings support the broad hypothesis that high-and low-hostile respondents will show different MCAP responses to pharmacologically induced alterations in SNS-PNS balance. Such differences could contribute to accelerated atherogenesis among high-hostile individuals.

Journal Article↗
PubMed2001

Clinical applications of the relaxation response and mind-body interventions.

Several hundred peer-reviewed studies in the past 20 years have shown that the relaxation response and mind-body interventions are clinically effective in the treatment of many health problems that are caused or made worse by stress. Recent studies show that mind-body interventions may improve prognosis in coronary heart disease and can enhance immune functioning. It is hypothesized that mind-body interventions reduce sympathetic nervous system activation and increase parasympathetic nervous system activity, and thereby restore homeostasis. Researchers have also concluded that cognitive therapy is as effective, and possibly more effective than antidepressant medication in the treatment of major depression. This report provides an overview of some studies that have shown a beneficial role of the relaxation response and cognitive restructuring in the treatment of headaches, insomnia, and cardiovascular disorders. Studies to date suggest that mind-body interventions are effective and can also provide cost savings in patient treatment. It is also clear, however, that mind-body therapies are not panaceas, and should be used in conjunction with standard medical care.

Cardiovascular Diseases↗
PubMed1975

The effect of the parasympathetic autonomic nervous system on auditory fatigue.

Volunteers with normal hearing were tested for vegetative balance with the aid of vegetative reflexes and with the aid of the atropine test. The effect of white noise stimulated on hearing thresholds was then investigated together with their recovery. The vegetative system was affected experimentally by intravenous administration of atropine, and the beginning and recession of hearing fatigue was observed. Atropine caused a small change only. In a similarly arranged experiment, 1% pilocarpin administered subcutaneously in a dose of 1.4 minus 1.6 ml, resulted in increased hearing fatigue and retarded recovery at higher frequencies. The effect of pilocarpin is explained by the fact that it supports the inhibitory processes checked by the parasympathetic nervous system on the periphery.

Acetylcholine↗
PubMed1994

The role of the autonomic nervous system in the thermic effects of protein and carbohydrates in rats.

To investigate the roles of the autonomic nervous system in the thermic effects of protein and carbohydrates in rats, we determined the urinary excretion of catecholamines and the resting oxygen consumption by means of HPLC-fluorometry and open-circuit respirometry, respectively. Protein administration significantly increased the urinary excretion of norepinephrine and epinephrine over those on water administration. The thermic effect of protein was 16.6% of the basal metabolic rate and was inhibited by phentolamine, prazosin, or atropine, but not by propranolol. These results suggest that the sympathetic nervous system via alpha 1-adrenoceptors and the parasympathetic nervous system are involved in the thermic effect of protein. The administration of carbohydrates such as glucose, sucrose, and fructose significantly enhanced the urinary excretion of norepinephrine, but only glucose administration increased the urinary excretion of epinephrine. The thermic effects of carbohydrates were 8-9% of the basal metabolic rate and were inhibited by propranolol, but not by phentolamine or atropine. These findings suggest that the sympathetic nervous system via beta-adrenoceptors, but not the parasympathetic nervous system, contributes to the thermic effect of carbohydrates. Thus, we conclude that the autonomic nervous system is involved in the thermic effects of protein and carbohydrates by different mechanisms.

Animals↗
PubMed1999

Control of pulmonary surfactant secretion from type II pneumocytes isolated from the lizard Pogona vitticeps.

Pulmonary surfactant, a mixture consisting of lipids and proteins and secreted by type II cells, functions to reduce the surface tension of the fluid lining of the lung, and thereby decreases the work of breathing. In mammals, surfactant secretion appears to be influenced primarily by the sympathetic nervous system and changes in ventilatory pattern. The parasympathetic nervous system is not believed to affect surfactant secretion in mammals. Very little is known about the factors that control surfactant secretion in nonmammalian vertebrates. Here, a new methodology for the isolation and culture of type II pneumocytes from the lizard Pogona vitticeps is presented. We examined the effects of the major autonomic neurotransmitters, epinephrine (Epi) and ACh, on total phospholipid (PL), disaturated PL (DSP), and cholesterol (Chol) secretion. At 37 degrees C, only Epi stimulated secretion of total PL and DSP from primary cultures of lizard type II cells, and secretion was blocked by the beta-adrenoreceptor antagonist propranolol. Neither of the agonists affected Chol secretion. At 18 degrees C, Epi and ACh both stimulated DSP and PL secretion but not Chol secretion. The secretion of surfactant Chol does not appear to be under autonomic control. It appears that the secretion of surfactant PL is predominantly controlled by the autonomic nervous system in lizards. The sympathetic nervous system may control surfactant secretion at high temperatures, whereas the parasympathetic nervous system may predominate at lower body temperatures, stimulating surfactant secretion without elevating metabolic rate.

Acetylcholine↗
PubMed1977

Fisher's syndrome: a pharmacological study of the pupils.

A pharmacological study was performed in the involved pupils to demonstrate the site of lesion in a patient with Fisher's syndrome who showed marked ptosis, complete external ophthalmoplegia, pupillary involvement with anisocoria, facial paresis, ataxia, areflexia, and albuminocytological dissociation in the cerebrospinal fluid. The instillation of 2.5% methacholine produced mild constriction of one pupil. This response was not detectable in the recovery stage. The instillation of 1.25% l-epinephrine produced marked bilateral dilation of the pupils, in both the early and recovery stages. Instillation of 5% tyramine produced pupillary dilation as in the normal pupil. The response to 5% cocaine, tested only in the recovery stage, was weak in one pupil. These results imply that the pupillary involvement was due to peripheral involvement of the sympathetic and parasympathetic nervous systems. The lesion in the sympathetic nervous system was preganglionic, but in the parasympathetic nervous system the precise localization could not be determined.

Aged↗
PubMed1993

[Functional assessment of the autonomic nervous system in rheumatoid arthritis].

Sympathetic and parasympathetic nervous system evaluation was performed in 21 patients with rheumatoid arthritis. Every patient had autonomic nervous system (ANS) dysfunction, the parasympathetic involvement being the most frequent. ANS dysfunction may explain some manifestations and may well be the expression of a larger neuropathic involvement with pathogenic implications.

Adult↗
PubMed2005

Association of C825T polymorphism of G protein beta3 subunit with the autonomic nervous system in young healthy Japanese individuals.

BACKGROUND: The T allele of the C825T polymorphism of the G protein beta3 subunit gene (GNB3) is reported to be associated with increased intracellular signal transduction and the prevalence of essential hypertension. Because the two major receptors in the autonomic nervous system (ANS), the adrenergic and muscarinic acetylcholine receptors, are G protein-coupled receptors, it was expected that the GNB3 C825T polymorphism was associated with ANS function. In the present study, we have investigated the association of this polymorphism with ANS in young, healthy Japanese male individuals. METHODS: A total of 94 young, healthy subjects underwent the genotyping for the GNB3 C825T polymorphism and electrocardiogram R-R interval power spectral analysis in supine rest and standing positions. RESULTS: There were no significant differences among genotypes in any of the characteristics investigated (body mass index, blood pressure, plasma glucose, insulin, lipids, and family history of hypertension, diabetes, or obesity). However, in power spectral analysis of heart rate variability, the very-low-frequency component when standing was higher in TT carriers than in CC carriers, and TT and CT carriers had a significantly higher sympathetic nervous system (SNS) index and lower parasympathetic nervous system (PNS) index when standing than CC carriers. In addition, we found that TT carriers showed no chronological variations in either SNS or PNS index after postural change. CONCLUSIONS: These observations suggested that GNB3 C825T polymorphism is associated with ANS in youth. These findings raise the possibility that individuals who are T allele carriers are at increased risk for developing hypertension in relation to ANS function.

Adult↗
PubMed2000

Control of pulmonary surfactant secretion: an evolutionary perspective.

Pulmonary surfactant, a mixture consisting of phospholipids (PL) and proteins, is secreted by type II cells in the lungs of all air-breathing vertebrates. Virtually nothing is known about the factors that control the secretion of pulmonary surfactant in nonmammalian vertebrates. With the use of type II cell cultures from Australian lungfish, North American bullfrogs, and fat-tailed dunnarts, we describe the autonomic regulation of surfactant secretion among the vertebrates. ACh, but not epinephrine (Epi), stimulated total PL and disaturated PL (DSP) secretion from type II cells isolated from Australian lungfish. Both Epi and ACh stimulated PL and DSP secretion from type II cells of bullfrogs and fat-tailed dunnarts. Neither Epi nor ACh affected the secretion of cholesterol from type II cell cultures of bullfrogs or dunnarts. Pulmonary surfactant secretion may be predominantly controlled by the autonomic nervous system in nonmammalian vertebrates. The parasympathetic nervous system may predominate at lower body temperatures, stimulating surfactant secretion without elevating metabolic rate. Adrenergic influences on the surfactant system may have developed subsequent to the radiation of the tetrapods. Furthermore, ventilatory influences on the surfactant system may have arisen at the time of the evolution of the mammalian bronchoalveolar lung. Further studies using other carefully chosen species from each of the vertebrate groups are required to confirm this hypothesis.

Animals↗
PubMed2001

Evaluation of autonomic nervous system function with spectral analysis of heart rate variability in a case of tetanus.

The autonomic nervous system is affected in a wide variety of neurological disorders. Its dysfunction may play an important role in the clinical course and may result in serious complications, such as cardiac arrest. We report a case of tetanus who presented with severe autonomic nervous system dysfunction which was detected by spectral analysis of heart rate variability monitored over 24 h. This is a semi-quantitative method for evaluation of the status of the autonomic nervous system. In the present case, the analysis revealed profoundly decreased activity of both sympathetic and parasympathetic nervous system modulation of cardiac rhythm. The parasympathetic nervous system activity was more severely impaired than that of the sympathetic nervous system. The relative predominance of the sympathetic nervous system in the present case may have resulted in unopposed sympathetic nervous system hyperactivity manifested in this patient by tachycardia and excessive sweating. We further infer that the documented diminished buffering capacity of the autonomic nervous system may have lead to a sudden cardiac arrest in our case. Thus, spectral analysis of heart rate variability is a non-invasive and sensitive method for evaluating the status of the autonomic nervous system of critically ill patients in the hospital setting.

Arrhythmias, Cardiac↗
PubMed1989

Autonomic influence on cardiovascular performance in diabetic subjects.

PURPOSE: Cardiomyopathy, coronary artery atherosclerosis, or autonomic neuropathy may affect the cardiovascular performance of the diabetic patient. To evaluate the role of parasympathetic nervous system activity on cardiovascular performance, 25 diabetic subjects who lacked symptoms, signs, or objective measurements of ischemia or cardiomyopathy were studied. PATIENTS AND METHODS: Diabetic subjects were classified according to their RR variation, an index of cardiac parasympathetic nervous system activity. Fourteen diabetic subjects had a normal RR variation of greater than 30 (D-NOR), and 11 diabetic patients had an abnormal RR variation of less than 20 (D-ABN). Fifteen age- and weight-matched, healthy, nondiabetic subjects (NOR) constituted the control group. All subjects had oxygen consumption, multigated acquisition determination of cardiac output, and work product measured before and during supine bicycle maximum exercise testing. RESULTS: There was no difference in the resting cardiac output among the groups. Resting work product, however, was greatest in the D-ABN group when compared with performance in the other two groups (D-ABN: 11,500 +/- 800; D-NOR: 9,000 +/- 600; NOR: 8,700 +/- 400; p less than 0.0025). This was due to an increase in both heart rate (p less than 0.025) and systolic blood pressure (p less than 0.015). In the diabetic subjects, there was an inverse relationship between the RR variation and resting work product (r = 0.47, n = 25, p less than 0.005). In response to exercise, the percent increase in cardiac output at matched percent maximum oxygen uptake was greatest in the NOR, D-NOR, and D-ABN groups, respectively (analysis of variance, p less than 0.01). In the diabetic subjects, there was a significant relationship between the RR variation and the maximum percent change in cardiac output (r = 0.41, n = 25, p less than 0.02). Compared with the NOR group, the maximum increase in work product was impaired in diabetic subjects (p less than 0.002) and not different between the D-NOR and D-ABN groups. CONCLUSIONS: The increase in resting work product and the poor cardiac output responses to exercise in the D-ABN group are due to a decrease in cardiac parasympathetic nervous system activity and can be suggested by an abnormal RR variation. This index of parasympathetic nervous system activity can help the physician identify that subset of diabetic patients that may need special consideration when exercise training is prescribed.

Adult↗