Abstract:
:A great deal of knowledge exists regarding neural control of myocardial function in the rat. Most of the studies addressing this issue were conducted either under general anaesthesia or in isolated hearts in vitro. Our principal aim was to provide a detailed quantitative description of mechanisms controlling cardiac contractility in the rat, in an anaesthetic-free preparation with a preserved functional brainstem. Furthermore, while vagally mediated negative inotropy is a well-known phenomenon, at present there is no direct evidence for its presence in the rat; we searched for such evidence. To this end, in the arterially perfused working heart-brainstem preparation of the rat, we measured left ventricular pressure (LVP) and computed its first derivative (LVdP/dt). We made the following new observations. (i) Zatebradine (cardiac sodium pacemaker current blocker) caused a bradycardia associated with increases in LVP and LVdP/dt; the latter effect was via a frequency-dependent mechanism. (ii) We confirmed that in the rat, the force-frequency relationship (dependence of contractility on heart rate) is positive over a low range of heart rates, and negative and linear at physiological levels of heart rate, and provided its quantitative description. (iii) The increase in systemic pressure caused a rise in contractility, and vagal blockade or destruction of the central nervous system did not alter this inotropic effect, suggesting that it was mediated by intrinsic cardiac mechanisms. (iv) Vagal stimulation caused complex polyphasic changes in LVdP/dt and LVP in unpaced preparations; during pacing, it caused slowly developing falls in LVdP/dt that could be prevented by atropine. We conclude that control of ventricular contractility in the rat heart differs from that in other mammals not only by its negative frequency dependence, but also in the potent influence of aortic pressure on LVdP/dt. At the level of autonomic neural control, our newly found, vagally mediated negative inotropic effect adds to the accumulating body of data regarding both the presence and the functional importance of parasympathetic innervation of the ventricular myocardium.
journal_name
Exp Physioljournal_title
Experimental physiologyauthors
Nalivaiko E,Antunes VR,Paton JFdoi
10.1113/expphysiol.2009.048710subject
Has Abstractpub_date
2010-01-01 00:00:00pages
107-19issue
1eissn
0958-0670issn
1469-445Xpii
expphysiol.2009.048710journal_volume
95pub_type
杂志文章abstract:NEW FINDINGS:What is the topic of this review? This review describes the role of renal nerves as the key carrier of signals from the kidneys to the CNS and vice versa; the brain and kidneys communicate through this carrier to maintain homeostasis in the body. What advances does it highlight? Whether renal or autonomic ...
journal_title:Experimental physiology
pub_type: 杂志文章,评审
doi:10.1113/expphysiol.2014.079889
更新日期:2015-04-20 00:00:00
abstract::Simultaneous portal blood absorption and intestinal mucosal catabolism of labelled fatty acids were investigated. Anaesthetized adult Wistar rats were infused intraduodenally either with 90 mumol of capric (C10:0), oleic (C18:1), linoleic (C18:2) or arachidonic (C20:4) 1-14C acids or with 30 mumol of each labelled fat...
journal_title:Experimental physiology
pub_type: 杂志文章
doi:10.1113/expphysiol.1991.sp003511
更新日期:1991-05-01 00:00:00
abstract::Lower body negative pressure (LBNP) reduces central venous pressure (CVP) and cardiac output. The elderly are reported to have a limited capacity to increase cardiac output by increasing heart rate (HR), are especially dependent on end diastolic volume to maintain stroke volume and therefore should be especially vulne...
journal_title:Experimental physiology
pub_type: 杂志文章
doi:10.1113/eph8602153
更新日期:2001-05-01 00:00:00
abstract:NEW FINDINGS:What is the topic of this review? I focus on clinical aspects of uterine physiology, specifically, myometrial contractility. I bring together and contrast findings using physiological approaches and those using newer techniques, 'omics'. What advances does it highlight? Physiological studies have recently ...
journal_title:Experimental physiology
pub_type: 杂志文章,评审
doi:10.1113/EP085131
更新日期:2015-12-01 00:00:00
abstract::The effects on vasopressin and cortisol secretion of centrally and peripherally administered cholecystokinin octapeptide (CCK) were investigated in conscious prepubertal pigs. Injection of 1.3 micrograms CCK into the lateral cerebral ventricle resulted in a sustained increase in plasma vasopressin after a latency of 5...
journal_title:Experimental physiology
pub_type: 杂志文章
doi:10.1113/expphysiol.1991.sp003518
更新日期:1991-07-01 00:00:00
abstract:NEW FINDINGS:What is the central question of this study? This study was designed to investigate the molecular mechanism and biological roles of long non-coding RNA activated by transforming growth factor-β (lncRNA ATB) in the progression of cervical cancer. What is the main finding and its importance? Our study provide...
journal_title:Experimental physiology
pub_type: 杂志文章
doi:10.1113/EP087656
更新日期:2019-06-01 00:00:00
abstract::In anaesthetized cats, it was possible to enhance the dynamic sensitivity to stretch of jaw muscle spindle primary afferents by electrical stimulation in the midbrain. This effect was taken to be due to excitation of dynamic fusimotor neurones and was used to identify fusimotor fibres as static or dynamic in recording...
journal_title:Experimental physiology
pub_type: 杂志文章
doi:10.1113/expphysiol.1993.sp003667
更新日期:1993-01-01 00:00:00
abstract:NEW FINDINGS:What is the central question of this study? Loss of taste or inability to distinguish between different tastes progresses with age. The purpose was to evaluate the age-dependent changes in taste by studying the electrophysiological properties of taste receptor cells. What is the main finding and its import...
journal_title:Experimental physiology
pub_type: 杂志文章
doi:10.1113/EP089104
更新日期:2020-11-10 00:00:00
abstract:NEW FINDINGS:What is the topic of this review? This article describes the contribution of oxidative stress and pro-inflammatory cytokines to the enhanced carotid body chemosensory responsiveness to the hypoxia and systemic hypertension induced by chronic intermittent hypoxia. What advances does it highlight? Chronic in...
journal_title:Experimental physiology
pub_type: 杂志文章,评审
doi:10.1113/expphysiol.2014.079525
更新日期:2015-02-01 00:00:00
abstract::The purpose of the present study was to investigate the effect of temperature on the rates of isometric force development and relaxation in electrically activated fresh and fatigued human adductor pollicis muscle. Following immersion of the lower arm for 20 min in water baths of four different temperatures, muscle tem...
journal_title:Experimental physiology
pub_type: 杂志文章
doi:10.1017/s0958067099018953
更新日期:1999-11-01 00:00:00
abstract::Neural mediation of the human cardiac response to isocapnic (IC) steady-state hypoxaemia was investigated using coarse-graining spectral analysis of heart rate variability (HRV). Six young adults were exposed in random order to a hypoxia or control protocol, in supine and sitting postures, while end-tidal PCO2 (PET,CO...
journal_title:Experimental physiology
pub_type: 临床试验,杂志文章,随机对照试验
doi:
更新日期:2000-03-01 00:00:00
abstract:NEW FINDINGS:What is the central question of this study? What is the role of lncRNA PRRT3-AS1 in the regulation of peroxisome proliferator-activated receptor γ (PPARγ) gene-mediated mechanistic target of rapamycin (mTOR) signalling pathway in proliferation, apoptosis and autophagy of prostate cancer cells? What is the ...
journal_title:Experimental physiology
pub_type: 杂志文章
doi:10.1113/EP088011
更新日期:2020-05-01 00:00:00
abstract::Polycystic ovary syndrome (PCOS) is one of the most common endocrine disorders in women, with a prevalence of 8-12% during the reproductive years. In the present study, using prenatal exposure to a single dose of testosterone during the critical period of fetal development, we aimed to introduce an enhanced rat model ...
journal_title:Experimental physiology
pub_type: 杂志文章
doi:10.1113/expphysiol.2014.078055
更新日期:2014-05-01 00:00:00
abstract::Rats were fed a liquid diet with the aim of decreasing nervous reflex activity in the parotid glands. In rats killed after 21 days on this diet the glands were atrophied and the total amounts of the neuropeptides, substance P, vasoactive intestinal peptide and calcitonin gene-related peptide, were lower than in contro...
journal_title:Experimental physiology
pub_type: 杂志文章
doi:10.1113/expphysiol.1990.sp003435
更新日期:1990-07-01 00:00:00
abstract:NEW FINDINGS:What is the central question of this study? We modelled the alveolar pathway during breath holding on the hypothesis that it follows a hypoventilation loop on the O2 -CO2 diagram. What is the main finding and its importance? Validation of the model was possible within the range of alveolar gas compositions...
journal_title:Experimental physiology
pub_type: 杂志文章
doi:10.1113/EP088977
更新日期:2020-09-29 00:00:00
abstract::The role of testosterone (T) in the regulation of cardiovascular function in females is not well understood. Our goal was to examine the effect of T on cardiomyocyte biology by measuring sarcomere shortening/relaxation and intracellular calcium cycling in adult female Sprague-Dawley rats. The rats were divided into th...
journal_title:Experimental physiology
pub_type: 杂志文章
doi:10.1113/expphysiol.2012.067009
更新日期:2013-01-01 00:00:00
abstract:NEW FINDINGS:What is the central question of this study? Can low-dose inorganic nitrate supplementation prevent testicular structural and functional alterations in streptozotocin-induced type 1 diabetic male rats? What is the main finding and it's important? Treatment with a low dose of inorganic nitrate for 2 months h...
journal_title:Experimental physiology
pub_type: 杂志文章
doi:10.1113/EP087198
更新日期:2018-12-01 00:00:00
abstract::We tested the hypothesis that, among conditions of matched contractile work, shorter contraction durations and greater muscle fibre recruitment result in augmented skeletal muscle blood flow and oxygen consumption ( ) during steady-state exercise in humans. To do so, we measured forearm blood flow (FBF; Doppler ultras...
journal_title:Experimental physiology
pub_type: 杂志文章
doi:10.1113/expphysiol.2011.062968
更新日期:2012-06-01 00:00:00
abstract::To better understand the mechanisms underlying the pulmonary O(2) uptake (V(O(2P))) slow component during high-intensity exercise, we used (31)P magnetic resonance spectroscopy, gas exchange, surface electromyography and near-infrared spectroscopy measurements to examine the potential relationship between the slow com...
journal_title:Experimental physiology
pub_type: 杂志文章
doi:10.1113/expphysiol.2011.062927
更新日期:2012-08-01 00:00:00
abstract:NEW FINDINGS:What is the central question of this study? Are the urinary concentrations of NO and ATP, and their metabolites, associated with the severity of symptoms of overactive bladder? What is the main finding and its importance? The urinary ratios of [ATP/NO], [ADP/NO] and a combination of these, [ATP/Cr*ADP/Cr]/...
journal_title:Experimental physiology
pub_type: 杂志文章
doi:10.1113/EP088450
更新日期:2020-06-01 00:00:00
abstract::Sympathetic baroreflex sensitivity is increased during selective activation of the skeletal muscle metaboreflex with postexercise ischaemia (PEI) in young adults. However, to date, there are no data demonstrating this neural interaction between the arterial baroreflex and the muscle metaboreflex in healthy older adult...
journal_title:Experimental physiology
pub_type: 杂志文章
doi:10.1113/expphysiol.2013.073189
更新日期:2013-10-01 00:00:00
abstract:NEW FINDINGS:What is the central question of this study? What is the role of microRNA-424-5p (miR-424-5p) in aortic smooth muscle cells? How does miR-424-5p function as a suppressor of the inflammatory response? What is the main finding and its importance? Upregulation of miR-424-5p inhibits the inflammatory response i...
journal_title:Experimental physiology
pub_type: 杂志文章
doi:10.1113/EP088088
更新日期:2020-06-01 00:00:00
abstract::Embryonic stem (ES) cells are pluripotent cells isolated from the inner cell mass of blastocysts. ES cells are able to differentiate into the three primitive layers (endoderm, mesoderm and ectoderm) of the organism, including the germline. To study early stages of development, as well as to investigate the impact of a...
journal_title:Experimental physiology
pub_type: 杂志文章,评审
doi:
更新日期:2000-11-01 00:00:00
abstract:NEW FINDINGS:What is the central question of this study? Is chemerin, an adipokine implicated in obesity, increased in neonates following in utero cigarette smoke exposure. What is the main finding and its importance? Chemerin mRNA expression was increased and chemerin DNA methylation was decreased in babies born to mo...
journal_title:Experimental physiology
pub_type: 杂志文章
doi:10.1113/EP087307
更新日期:2019-01-01 00:00:00
abstract::The endothelial glycocalyx layer of capillaries was stained with Ruthenium Red and examined by transmission electron microscopy in rat extensor hallucis proprius muscles after 2 or 4 days of indirect electrical stimulation via implanted electrodes. The layer appeared continuous on the luminal surface of 63% capillarie...
journal_title:Experimental physiology
pub_type: 杂志文章
doi:10.1113/expphysiol.1996.sp003989
更新日期:1996-11-01 00:00:00
abstract::Recently, we reported the presence of a local renal aldosterone production. In the present study, we tested the hypothesis that local aldosterone production in the kidney contributes to renal inflammation, matrix formation and albuminuria associated with diabetes. We evaluated changes in renal aldosterone content (RAC...
journal_title:Experimental physiology
pub_type: 杂志文章
doi:10.1113/expphysiol.2008.042085
更新日期:2008-07-01 00:00:00
abstract::After 2 months of streptozotocin-induced diabetes in rats, the membrane potential of the diaphragm muscle when measured in vitro at 30 degrees C was unchanged but the tetanic tension, the half-relaxation time of the isometric twitch and the fatigue resistance were each reduced. Treatment of the diabetic rats with the ...
journal_title:Experimental physiology
pub_type: 杂志文章
doi:10.1113/expphysiol.1998.sp004131
更新日期:1998-07-01 00:00:00
abstract::The nucleus tractus solitarii (NTS) is a key central link in control of multiple homeostatic reflexes. A number of studies have demonstrated that exogenous and endogenous nitric oxide (NO) within NTS regulates visceral function, but further understanding of the role of NO in the NTS is hampered by the lack of informat...
journal_title:Experimental physiology
pub_type: 杂志文章
doi:10.1113/expphysiol.2006.036103
更新日期:2007-03-01 00:00:00
abstract:NEW FINDINGS:What is the central question of this study? Does treatment of obstructive sleep apnoea (OSA) with nocturnal oxygen or continuous positive airway pressure (CPAP) improve hypoxic vascular responses, which are reportedly impaired in OSA? What is the main finding and its importance? Cerebrovascular and cardiov...
journal_title:Experimental physiology
pub_type: 杂志文章
doi:10.1113/EP086845
更新日期:2019-04-01 00:00:00
abstract::Power spectral analysis of heart rate variability has often been used to assess cardiac autonomic function; however, the relationship of low-frequency (LF) power of heart rate variability to cardiac sympathetic tone has been unclear. With or without adjustment for high-frequency (HF) power, total power or respiration,...
journal_title:Experimental physiology
pub_type: 杂志文章,评审
doi:10.1113/expphysiol.2010.056259
更新日期:2011-12-01 00:00:00