Abstract：
:We studied the effect of lowering the extracellular potassium concentration ([K+]o) on the electrophysiological actions of disopyramide phosphate, a new antiarrhythmic drug. At low [K+]o, therapeutic concentrations of disopyramide phosphate caused significantly less depression of action potential amplitude and maximum upstroke velocity of both Purkinje fiber and ventricular muscle action potentials. The drug shifted the membrane responsiveness curve along the voltage axis to more negative membrane potentials regardless of [K+]o. However, a greater shift occurred when [K+]o was normal. Disopyramide phosphate prolonged both action potential duration and effective refractory period in all fibers but there was consistently greater prolongation of these parameters at low [K+]o. More importantly, disopyramide phosphate altered repolarization time course of action potentials in such a way that action potentials with dissimilar durations throughout the ventricular conducting system became more equal. The drug was less effective in decreasing this disparity in action potential durations throughout the ventricles in the presence of low [K+]o. These modifications of the electrophysiological actions of disopyramide by low [K+]o suggest that a therapeutic concentration of disopyramide might have less of an antiarrhythmic effect in the presence of hypokalemia.
journal_name
Can J Physiol Pharmacoljournal_title
Canadian journal of physiology and pharmacologyauthors
Kus T,Sasyniuk BIdoi
10.1139/y78-018subject
Has Abstractpub_date
1978-02-01 00:00:00pages
139-49issue
1eissn
0008-4212issn
1205-7541journal_volume
56pub_type
杂志文章abstract：:The effect of estrogen on the passive characteristics of arteries is not known. We hypothesized that estrogen would increase arterial distensibility as part of its protective effect on the vasculature. Female Sprague-Dawley rats were ovariectomized at 11 weeks of age. One group received a placebo (n = 6), while two ot...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/cjpp-77-1-75
更新日期：1999-01-01 00:00:00
abstract：:The major hallmark of rotator cuff tendinopathies (RCT) is the disorganization of tendon extracellular matrix (ECM) which is due to decrease in the collagen I-to-collagen III ratio. In addition, the pathology of tendon matrisome remains asymptomatic and hypoxia has been identified to be the priming signal to initiate ...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/cjpp-2020-0314
更新日期：2020-08-15 00:00:00
abstract：:At a critical premature interval, atrial premature beats encounter sinus node refractoriness and are blocked on entering and fail to reset the sinus node, resulting in interpolation of the premature beat. The transition from reset to interpolated response has been used to define the effective refractory period of the ...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y89-195
更新日期：1989-10-01 00:00:00
abstract：:The mesangial cell is a contractile secreting cell found in a key position in the renal glomerulus. Several kidney and systemic diseases are associated with dysfunctions of the mesangial cells. We compared the effect of bradykinin (BK; B2 agonist) and des-Arg9-bradykinin (DBK; B1 agonist) on intracellular calcium mobi...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y95-116
更新日期：1995-07-01 00:00:00
abstract：:Obesity is associated with autonomic nervous system dysfunction. The aim of the study was to evaluate baroreflex sensitivity, an indicator of autonomic nervous function, in 20 obese children and adolescents in comparison with 20 age- and sex-matched nonobese subjects. All subjects were examined in the supine position ...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y09-041
更新日期：2009-07-01 00:00:00
abstract：:Hereditary muscular hypertrophy is a character that has been selected in several animal species for industrial meat production. The selection of this character in cattle produces animals of exceptional commercial value but ones with a lower aerobic capacity than that of conventional cattle. The purpose of this work wa...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y93-143
更新日期：1993-12-01 00:00:00
abstract：:The activity of the lipolytic system of the obese hyperglycemic mouse was assessed after treatment with physiological doses of thyroxin (T4). The treatment significantly increased fatty acid mobilization in response to adrenaline over the levels observed in the control mice under all conditions studied. The activities...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y77-177
更新日期：1977-12-01 00:00:00
abstract：:Endothelin 1 (ET-1) is a potent vasoconstrictor implicated in the control of blood pressure and renal function. Its effects can be modulated by nitric oxide (NO), which inhibits ET-1 production and action. Recently, we reported that ET-1 production can also be modulated by angiotensin II (AngII) in vivo. To investigat...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/cjpp-77-1-8
更新日期：1999-01-01 00:00:00
abstract：:Bicuculline methochloride (BMC), applied by microiontophoresis, tends to depolarize spinal motoneurons and lower their input resistance. With approximately equal iontophoretic currents of gamma-aminobutyric acid (GABA) and BMC, there is an almost equal chance of observing no change, a potentiation, or a depression of ...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y77-091
更新日期：1977-06-01 00:00:00
abstract：:Ethanol was administered to rats by oral intubation 3 h after intraperitoneal administration of calcium carbimide. Increased blood acetaldehyde concentration and the presence of acetaldehyde in brain were found for the calcium carbimide--ethanol interaction. There was no detectable brain acetaldehyde for ethanol admin...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y81-011
更新日期：1981-01-01 00:00:00
abstract：:Effect of Ni2+ on Zn2+-induced potentiation of twitch tension was studied electrophysiologically in the toe muscle fibers of Rana catesbeiana. The major findings of this investigation are as follows. When 2 mM Ni2+ was applied to fibers in a normal Ringer's solution containing 50 microM Zn2+ (Zn2+ solution), the Zn2+-...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y86-104
更新日期：1986-05-01 00:00:00
abstract：:Clonidine was administered to isolated guinea pig right atria in order to characterize its chronotropic activity and its interaction with other chronotropic agents at the postjunctional level. Clonidine either had no significant effect (10(-7)--10(-4) M) or decreased (10(-3) M) atrial rate. Pretreatment of the atria w...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y80-006
更新日期：1980-01-01 00:00:00
abstract：:Liver diseases are associated with a decrease in hepatic drug elimination, but there is evidence that cirrhosis does not result in uniform changes of cytochrome P450 (CYP) isoenzymes. The objective of this study was to determine the content and activity of four CYP isoenzymes in the bile duct ligation and carbon tetra...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：
更新日期：2000-11-01 00:00:00
abstract：:Acrolein, a highly reactive alpha,beta-unsaturated aldehyde, is an omnipresent environmental pollutant. Chronic and acute human exposures occur through exogenous and endogenous sources, including food, vapors of overheated cooking oil, house and forest fires, cigarette smoke, and automobile exhaust. Acrolein is a toxi...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/Y09-134
更新日期：2010-03-01 00:00:00
abstract：:Urinary output of Na+ and K+, and volume of urine have been studied in conscious, unrestrained, water-loaded male rats following the intraseptal injection of catecholamines. Natriuresis and kaliuresis increased after injecting noradrenaline (NA), the intensity being dose related. The dose-response curve suggests that ...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y76-034
更新日期：1976-06-01 00:00:00
abstract：:Calcium-activated chloride channels (ClCa) are ligand-gated anion channels as they have been shown to be activated by a rise in intracellular Ca2+ concentration in various cell types including cardiac, skeletal and vascular smooth muscle cells, endothelial and epithelial cells, as well as neurons. Because ClCa channel...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章,评审
doi：10.1139/y05-040
更新日期：2005-07-01 00:00:00
abstract：:The bioavailabilities of aspirin (acetylsalicylic acid) and of salicylic acid were studied in male Wistar rats after acute and chronic administration of a Capsicum annuum extract, containing 100 mg of capsaicin per gram. With a single administration of 100 mg/kg of the extract, aspirin blood levels remained unchanged,...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：
更新日期：1999-06-01 00:00:00
abstract：:We examined whether there was a threshold for change in fetal arterial PO2 to elicit alterations in plasma adrenocorticotropic hormone, arginine vasopressin, or cortisol, or to affect the incidence of fetal breathing movements or eye movements and we determined whether such a threshold changed with gestational age. Fe...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y90-080
更新日期：1990-05-01 00:00:00
abstract：:Glycine has been used to reduce oxidative stress and proinflammatory mediators in some metabolic disorders; however, its effect on the vasculature has been poorly studied. The aim of this work was to explore the effect of glycine on endothelial dysfunction in aged rats. Aortic rings with intact or denuded endothelium ...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/cjpp-2014-0393
更新日期：2015-06-01 00:00:00
abstract：:Airway smooth muscle (ASM) contraction controls the airway caliber. Airway narrowing is exaggerated in obstructive lung diseases, such as asthma and chronic obstructive pulmonary disease (COPD). The mechanism by which ASM tone is dysregulated in disease is not clearly understood. Recent research on ion channels, parti...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章,评审
doi：10.1139/cjpp-2014-0417
更新日期：2015-03-01 00:00:00
abstract：:The purpose of this study was to examine the effects of norepinephrine infusion alone and during alkalosis on oxygen uptake in the dog gastrocnemius-plantaris muscle group under conditions of constant muscle blood flow. The animals were not cold acclimatized. Blood flow was pump controlled, alkalosis was produced by h...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y80-016
更新日期：1980-01-01 00:00:00
abstract：:Physical exercise is essential for the amelioration of insulin resistance. The mechanisms in charge of improved insulin resistance, regulated by exercise, are insufficient inquired. Previous researches revealed that SIRT6-mediated insulin signaling acts a crucial character in hepatic IR. The objective of our research ...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/cjpp-2020-0083
更新日期：2020-09-24 00:00:00
abstract：:Immediately following exposure to thiocyanate (SCN-)-containing solutions, the cystic fibrosis conductance regulator Cl- channel exhibits high unitary SCN conductance and anomalous mole fraction behaviour, suggesting the presence of multiple anion binding sites within the channel pore. However, under steady-state cond...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：
更新日期：2001-07-01 00:00:00
abstract：:The heat production (HP), heart rate (HR), respiration rate, rumen motility, and body temperature responses to 2.5-h adrenaline (A) and noradrenaline (NA) intrajugular infusions at 0.00, 0.15, 0.30, 0.60, and 0.90 micrograms.kg-1.min-1 were studied in 10 shorn wethers which had been chronically (3-8 weeks) exposed to ...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y81-150
更新日期：1981-09-01 00:00:00
abstract：:Angiotensin exerts numerous contractile and secretory effects by activating specific receptors. Recent pharmacological findings obtained with this peptide in various laboratories are analyzed, using the order of potency of agonists and the affinity of competitive antagonists as criteria for the classification of recep...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章,评审
doi：10.1139/y79-020
更新日期：1979-02-01 00:00:00
abstract：:Glucosamine sulfate is a dietary supplement that is marketed as a treatment for osteoarthritis. Recent evidence from animal and cell culture models have suggested that glucosamine treatment can promote the misfolding of proteins and the activation of the unfolded protein response (UPR). We investigated whether glucosa...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/cjpp-2013-0318
更新日期：2014-04-01 00:00:00
abstract：:The shear-stress sensor function of vascular glycocalyx heparan sulphate and hyaluronic acid was investigated in vivo by assessing flow-mediated dilation before and after their removal. Heparinase III exposure (100 mU·mL-1 for 20 min;n = 6) did not significantly affect flow-mediated dilation of the iliac, from 0.42 ± ...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/cjpp-2019-0124
更新日期：2019-08-01 00:00:00
abstract：:The purpose of this study was to determine the interaction of three factors that modify twitch contraction amplitude in the rat gastrocnemius muscle in situ: posttetanic potentiation, fatigue, and caffeine. Posttetanic (200 Hz for 1 s) twitch responses were observed before and after 15 Hz stimulation for 6 min (group ...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y87-046
更新日期：1987-02-01 00:00:00
abstract：:The Na+/H+ exchanger isoform 1 is an integral membrane protein that regulates intracellular pH. It extrudes 1 intracellular H+ in exchange for 1 extracellular Na+. It has 2 large domains, an N-terminal membrane domain of 12 transmembrane segments and an intracellular C-terminal regulatory domain. We characterized the ...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y06-081
更新日期：2007-03-01 00:00:00
abstract：:The purpose of this study was to investigate the effects of bosentan, a mixed endothelin receptor A and B subtype antagonist, on myocardial ischemia-reperfusion injury and to explore the influence of the timing of bosentan administration on its cardioprotective effects. Adult rat hearts were perfused by the Langendorf...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y05-014
更新日期：2005-03-01 00:00:00
