Abstract:
:Single cells from the rabbit pulmonary artery were isolated using a new and convenient procedure. Strips of muscle were incubated overnight in papain at 6 degrees C and dispersed the following morning after warming the tissue for 10 min. This method consistently produced a high yield of relaxed cells, which reversibly responded to vasoconstrictors and remained viable for many hours. The electrophysiological properties of these cells were studied using the patch-clamp technique in the whole-cell configuration. In physiological Ca2+ solution with K(+)-filled pipettes, cells had a high input resistance (approximately 17 G omega) and an average resting potential of -55 mV. In voltage clamp, several components of outward current could be identified. Depolarizing voltage steps revealed a prominent, transient current (Itran), having extremely rapid activation (less than 5 ms) and inactivation (less than 15 ms) kinetics. Itran was followed by a more slowly activating current (IKso) that was sustained over 100 ms. Both currents were essentially abolished by a 4-aminopyridine (4-AP) and sensitive to Ca2+ influx. IKso, but not Itran, was blocked by tetraethylammonium (TEA) and had the properties of a Ca(2+)-activated K+ current. Holding the membrane potential at -40 mV completely inactivated Itran and unmasked a time-independent, background current superimposed on IKso. The background current was also blocked by 4-AP. In addition, when adenosine triphosphate (ATP), but not guanosine triphosphate (GTP), was omitted from the patch-pipette, spontaneous bursts of outward current (SOCs) were superimposed on the voltage-activated currents. However, since SOCs were rarely observed when ATP and GTP were present together, they are unlikely to be active under physiological conditions. Thus at least four types of outward current can be distinguished in isolated rabbit pulmonary artery cells. These include a novel transient current which could be activated from the resting potential. It activates much more rapidly than outward currents previously reported in vascular muscle, and would rapidly oppose action potential firing. This current could therefore be responsible for the inability of large elastic arteries to fire action potentials.
journal_name
Exp Physioljournal_title
Experimental physiologyauthors
Clapp LH,Gurney AMdoi
10.1113/expphysiol.1991.sp003535subject
Has Abstractpub_date
1991-09-01 00:00:00pages
677-93issue
5eissn
0958-0670issn
1469-445Xjournal_volume
76pub_type
杂志文章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::The spatiotemporal dynamics of intracellular calcium within the middle cerebral artery (MCA) isolated from stroke-prone spontaneously hypertensive rats (SHR-SP) were investigated using real-time confocal laser microscopy. At 3 months of age (prestroke), rhythmical changes in the [Ca(2+)](i) during the tonic phase were...
journal_title:Experimental physiology
pub_type: 杂志文章
doi:10.1113/expphysiol.2011.061499
更新日期:2012-02-01 00:00:00
abstract::Growing lambs fed a diet containing NaHCO3 were made acidotic by intravenously infusing HCl at the rate of 1 mmol/min over a 4 h period. Acid infusion led to a fall in blood and urine pH and a prompt increase in urinary Ca excretion. This in turn led to a fall in plasma Ca concentration and a rise in parathyroid hormo...
journal_title:Experimental physiology
pub_type: 杂志文章
doi:10.1113/expphysiol.1993.sp003676
更新日期:1993-03-01 00:00:00
abstract::We measured plasma levels of L-arginine, its analogue NG-monomethyl-L-arginine (L-NMMA), and related amino acids in normal subjects and uraemic patients (n = 31), before and after haemodialysis. Plasma levels of L-arginine were reduced to less than half of normal values in uraemic subjects compared with controls, and ...
journal_title:Experimental physiology
pub_type: 杂志文章
doi:10.1113/expphysiol.1996.sp003950
更新日期:1996-05-01 00:00:00
abstract::The vascular actions of insulin are complex, because it can stimulate both nitric oxide-mediated dilatation and endothelin (ET)-1-mediated constriction. We examined vasoreactivity to insulin in isolated feed arteries of the gastrocnemius (GFA) and soleus muscles (SFA) of 32-week-old Long-Evans Tokushima Otsuka (LETO) ...
journal_title:Experimental physiology
pub_type: 杂志文章
doi:10.1113/expphysiol.2013.074047
更新日期:2014-01-01 00:00:00
abstract::Therapeutic angiogenesis/vasculogenesis holds promise for the cure of ischaemic disease. The approach postulates the manipulation of spontaneous healing response by supplementation of growth factors or transplantation of vascular progenitor cells. These supplements are intended to foster the formation of arterial coll...
journal_title:Experimental physiology
pub_type: 杂志文章,评审
doi:10.1113/expphysiol.2004.028571
更新日期:2005-05-01 00:00:00
abstract:NEW FINDINGS:What is the topic of this review? This review covers recent evidence highlighting the crucial pathophysiological roles and molecular mechanisms of the bone morphogenetic protein (BMP) signalling pathway during the progression of pulmonary hypertension (PH) and discusses targeting of BMP signalling as a new...
journal_title:Experimental physiology
pub_type: 杂志文章,评审
doi:10.1113/EP086041
更新日期:2017-09-01 00:00:00
abstract:NEW FINDINGS:What is the central question of this study? What mechanisms account for the hypotension observed during chronic elevations in circulating 5-hydroxytryptamine in rats? What is the main finding and its importance? Chronic 5-hydroxytryptamine-induced hypotension requires continued activation of the 5-HT7 rece...
journal_title:Experimental physiology
pub_type: 杂志文章
doi:10.1113/EP088919
更新日期:2020-10-14 00:00:00
abstract::A global and transient rise of intracellular Ca2+ (Ca2+i) is central to the operation of pump-leak coupling in the frog early distal tubule (EDT). The endoplasmic reticulum (ER) is the site of this Ca2+ release and reuptake; however, it is likely that other intracellular pools, such as mitochondria, also contribute to...
journal_title:Experimental physiology
pub_type: 杂志文章
doi:10.1113/expphysiol.2004.028886
更新日期:2005-03-01 00:00:00
abstract::The objective of the experiments was to investigate the cellular basis of the inotropic effect on myocardium of several opioids which have been implicated in producing cardiotoxic effects in human poisoning. Opioids exerted negative inotropic effects, with half-maximal concentrations between 10 microM (dextropropoxyph...
journal_title:Experimental physiology
pub_type: 杂志文章
doi:10.1113/expphysiol.1997.sp004021
更新日期:1997-03-01 00:00:00
abstract:NEW FINDINGS:What is the central question of this study? Does a previously hypothesized signalling mechanism, believed to detect postprandial increases in intestinal phosphate and that can stimulate the kidneys to rapidly excrete phosphate, operate under physiological conditions? What is the main finding and its import...
journal_title:Experimental physiology
pub_type: 杂志文章
doi:10.1113/EP086062
更新日期:2017-04-01 00:00:00
abstract::The inward transport of two purines, adenosine and hypoxanthine, at 37 degrees C by horse erythrocytes was compared. No mediated transport of adenosine was detected in horse erythrocytes, nor was saturable, high-affinity binding of the potent facilitated-diffusion inhibitor nitrobenzylthioinosine demonstrable in horse...
journal_title:Experimental physiology
pub_type: 杂志文章
doi:10.1113/expphysiol.1998.sp004104
更新日期:1998-03-01 00:00:00
abstract:NEW FINDINGS:What is the central question of the study? What are the effects of age and fitness on the vascular response to acute inflammation in younger and older adults? What is the main finding and its importance? In older adults, cardiorespiratory fitness level has a differential impact on endothelial function afte...
journal_title:Experimental physiology
pub_type: 杂志文章
doi:10.1113/EP086922
更新日期:2018-06-01 00:00:00
abstract::Pairs of Ia and II afferent fibres supplying primary and secondary endings lying in the same tenuissimus spindles were prepared in barbiturate anaesthetized cats in order to compare the variability in the rhythm of discharge of the two endings during responses elicited by the contraction of different intrafusal muscle...
journal_title:Experimental physiology
pub_type: 杂志文章
doi:10.1113/expphysiol.1994.sp003801
更新日期:1994-09-01 00:00:00
abstract:NEW FINDINGS:What is the central question of this study? Is mesenchymal stem cell-conditioned medium capable of improving the pathological alterations of ovalbumin-induced asthma in mice? What is the main finding and its importance? Our study indicated that human amniotic membrane mesenchymal stem cell-conditioned medi...
journal_title:Experimental physiology
pub_type: 杂志文章
doi:10.1113/EP088911
更新日期:2020-12-01 00:00:00
abstract:NEW FINDINGS:What is the central question of this study? Research has reported that some sensory input, such as auditory and olfactory input, can affect subliminal visual processing. However, it is important to address whether tactile input, another form of elementary sensory input, could influence the interocular riva...
journal_title:Experimental physiology
pub_type: 杂志文章
doi:10.1113/EP087944
更新日期:2019-11-01 00:00:00
abstract::Uterine and umbilical blood flows were measured in pregnant sheep (125-142 days gestation) under normothermic and hyperthermic conditions using the Fick principle with [14C]antipyrine as the indicator. Exposure of the sheep to an ambient temperature of 43 +/- 1 degrees C (25-30% relative humidity) for 8 h increased ma...
journal_title:Experimental physiology
pub_type: 杂志文章
doi:10.1113/expphysiol.1994.sp003735
更新日期:1994-01-01 00:00:00
abstract::The effect of mechanical loading on the negative inotropic effect of acidosis in isolated rat ventricular myocytes was investigated. The mechanical loading of the myocytes was changed by attaching carbon fibres to the ends of the cell. To monitor intracellular Ca2+ and Na+ concentrations, cells were loaded with fluore...
journal_title:Experimental physiology
pub_type: 杂志文章
doi:10.1113/expphysiol.1995.sp003879
更新日期:1995-09-01 00:00:00
abstract::Altering [K+]o might have different effects on action potential duration (APD) in myocytes from different regions. Therefore, the effects of [K+]o on regional differences in action potential characteristics were investigated in sub-endocardial, mid-myocardial and sub-epicardial myocytes isolated from the base of guine...
journal_title:Experimental physiology
pub_type: 杂志文章
doi:10.1111/j.1469-445x.2000.02048.x
更新日期:2000-11-01 00:00:00
abstract:NEW FINDINGS:What is the central question of this study? Could different hormonally active substances, including oestrogen receptor (ER) agonists, protect against oxidative brain damage and memory impairment induced by a single epileptic seizure in rats? If so, which signalling mechanisms are involved in their anti-inf...
journal_title:Experimental physiology
pub_type: 杂志文章
doi:10.1113/EP087986
更新日期:2019-12-01 00:00:00
abstract::We estimated the transfer function of autonomic heart rate (HR) control by using random binary sympathetic or vagal nerve stimulation in anaesthetized rats. The transfer function from sympathetic stimulation to HR response approximated a second-order, low-pass filter with a lag time (gain, 4.29 +/- 1.55 beats min(1) H...
journal_title:Experimental physiology
pub_type: 杂志文章
doi:10.1113/expphysiol.2010.053090
更新日期:2010-09-01 00:00:00
abstract:NEW FINDINGS:What is the topic of this review? Excitation-contraction coupling in fish hearts is maintained over a range of temperatures that would be cardioplegic to most mammals. Here, we review what is known about the fish cardiac ryanodine receptor, and consider how it may be regulated in a different manner from th...
journal_title:Experimental physiology
pub_type: 杂志文章,评审
doi:10.1113/EP085136
更新日期:2015-12-01 00:00:00
abstract:NEW FINDINGS:What is the topic of this review? Patients with advanced heart failure who are implanted with left ventricular assist devices (LVADs) present an opportunity to understand the human circulation under extreme conditions. What advances does it highlight? LVAD patients have a unique circulation that is charact...
journal_title:Experimental physiology
pub_type: 杂志文章
doi:10.1113/EP088323
更新日期:2020-05-01 00:00:00
abstract:NEW FINDINGS:What is the topic of this review? We discuss tools available to access genome-wide data sets that harbour cell-specific, brain region-specific and tissue-specific information on exon usage for several species, including humans. In this Review, we demonstrate how to access this information in genome databas...
journal_title:Experimental physiology
pub_type: 杂志文章,评审
doi:10.1113/EP085129
更新日期:2015-12-01 00:00:00
abstract::An imaging technique (laser Doppler perfusion imaging, LDI), based on measurement of backscattered Doppler-broadened laser radiation, was used to provide two-dimensional images of perfusion in the exposed rat knee joint capsule. In control animals, frequency-dependent constriction of knee joint blood vessels occurred ...
journal_title:Experimental physiology
pub_type: 杂志文章
doi:10.1113/expphysiol.1995.sp003851
更新日期:1995-05-01 00:00:00
abstract::In this review we discuss our current understanding of the cellular basis of uterine contractility, highlighting those areas requiring further study. It is clear that the basic processes of excitation-contraction coupling lie within the myometrial cell, and that these may be modified by agonists. Pacemaker activity, h...
journal_title:Experimental physiology
pub_type: 杂志文章,评审
doi:10.1113/eph8602114
更新日期:2001-03-01 00:00:00
abstract::Flow of submandibular saliva and the constituents secreted during chorda-lingual nerve stimulation at 40 Hz (3 x 10 min) were studied after alpha- and beta-adrenergic blockade, and in the absence (control) or presence of cholinergic blockade in anaesthetized rats. Peroxidase and true tissue kallikrein (rK1) were asses...
journal_title:Experimental physiology
pub_type: 杂志文章
doi:10.1113/expphysiol.1996.sp003940
更新日期:1996-05-01 00:00:00
abstract::There is controversy about the effect of left ventricular pressure on resistance of the intramyocardial coronary vessels. In anaesthetized dogs the effect of left ventricular pressure on coronary flow during diastole was studied using an extracorporeal circulation and allowing the heart to contract and relax isovolumi...
journal_title:Experimental physiology
pub_type: 杂志文章
doi:10.1113/expphysiol.1992.sp003602
更新日期:1992-03-01 00:00:00
abstract:NEW FINDINGS:What is the central question of this study? Is an anti-oedematous effect of ghrelin associated with increased expression of tight junction proteins in the hypoxic brain? What is the main finding and its importance? We showed that injection of ghrelin during acute and chronic systemic hypoxia is associated ...
journal_title:Experimental physiology
pub_type: 杂志文章
doi:10.1113/EP086068
更新日期:2017-03-01 00:00:00
abstract::Chronically hypoxic (CH) and normoxic control rats were used to assess the action of S9581, a water-soluble analogue of almitrine bismesylate. S9581 increased ventilation (Ve) by 34% in control and 20% in CH rats. During acute hypoxia Ve was raised and S9581 caused a further increase of 20% in both groups. Low doses o...
journal_title:Experimental physiology
pub_type: 杂志文章
doi:10.1113/expphysiol.1992.sp003648
更新日期:1992-11-01 00:00:00