Abstract：
:In embryonic chick hearts during development, there are three inward current systems which are involved in the rising phases of the action potentials (APs): fast INa, slow ICa, and tetrodotoxin-insensitive slow INa. To assess reactivation processes for these three types of inward current channels (fast Na+, slow Ca2+, and slow Na+ channels), diastolic recovery of Vmax was examined in embryonic chick hearts using a paired-pulse protocol. In all cases, the diastolic recoveries were approximated by single exponential functions. The time constants of recovery (tau(V)) and T90% (the diastolic interval which allows 90% recovery of Vmax of the premature AP) were, respectively, 53.1 +/- 5.2 and 61.5 +/- 8.6 ms for Na+-dependent fast AP (n = 10), 376.9 +/- 49.3 and 659.2 +/- 113.1 ms for the Ca2+-dependent slow AP (n = 10), and 40.7 +/- 5.3 and 45.6 +/- 12.0 ms for the Na+-dependent slow AP (n = 10). In the presence of lidocaine, the recovery kinetics also appeared to be single exponentials for diastolic intervals up to 500 ms (fast APs) or 250 ms (slow APs). The reactivation processes for the Na+-dependent fast and slow channels were significantly slowed by 100 microM lidocaine. In addition, in the presence of 100 microM lidocaine, Vmax was depressed in a frequency-dependent manner; the higher the stimulation frequency, the greater the depression. Hence, the fast Na+ channels and the slow Na+ channels had the following similarities: rapid reactivation, reactivation slowed by lidocaine, and frequency-dependent depression in the presence of lidocaine.
journal_name
Can J Physiol Pharmacoljournal_title
Canadian journal of physiology and pharmacologyauthors
Sada H,Sada S,Sperelakis Ndoi
10.1139/y86-019subject
Has Abstractpub_date
1986-02-01 00:00:00pages
125-32issue
2eissn
0008-4212issn
1205-7541journal_volume
64pub_type
杂志文章abstract：:To determine the effects of chronic hyperinsulinemia on glucagon release, rats were made hyperinsulinemic for 14 days by supplementation of drinking water with sucrose (10%; sucrose-fed) to increase endogenous release or by implantation of osmotic minipumps (subcutaneous, s.c.; or intraperitoneal, i.p.) to deliver exo...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y91-066
更新日期：1991-03-01 00:00:00
abstract：:We have measured the responses to endurance exercise training on body composition and glucose regulation, as well as cardiovascular and liver structure and function in rats fed a high carbohydrate and high fat (HCHF) diet as a model of human metabolic syndrome. Male Wistar rats (9-10 weeks old) were randomly allocated...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y2012-097
更新日期：2012-11-01 00:00:00
abstract：:The metabolic and body weight changes in two non-pregnant beef cows were studied during prolonged exposure to warm (20 +/- 3 degrees C, relative humidity 50-70%) and cold (-10 +/- 2 or -25 +/- 4 degrees C) temperatures. Other factors including daily food intake were held constant throughout each 8-week exposure. Durin...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y75-129
更新日期：1975-10-01 00:00:00
abstract：:Phosphocreatine (PCr) and intracellular pH changes were monitored by 31P-NMR spectroscopy in isolated, arterially perfused cat biceps and soleus muscles, while the pH of the CO2-bicarbonate buffered perfusate was decreased from 7.1-7.4 to 6.4-6.7 by increasing the CO2 in the equilibrating gas from 5 to up to 70%. In b...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y91-047
更新日期：1991-02-01 00:00:00
abstract：:Hypertrophic scar (HS) results from abnormal wound healing, accompanied by excessive hypercellularity, migration and extracellular matrix (ECM) deposition. Autophagy dysregulation plays crucial roles during HS formation. The overexpressed p75 neurotrophin receptor (p75NTR) in injured skin tissue after wound healing be...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/cjpp-2020-0219
更新日期：2020-07-29 00:00:00
abstract：:Alterations of the ionic constituents of solutions perfused through the tissue of the posterior hypothalamic region in conscious cats elicited changes in body temperatures. Increasing the (Ca2+) to (Na+) ratio of the perfusion solution elicited falls in body temperature which were accompanied by changes in posture and...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y78-091
更新日期：1978-08-01 00:00:00
abstract：:Tension responses to ramp shortening of varying speed in whole muscle or single fibres from the plateau of an isometric tetanus, revealed at least two distinct phases. There was a fast initial drop in tension followed by a change of slope and a definite inflexion on the tension record. As the velocity of the imposed l...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y85-268
更新日期：1985-12-01 00:00:00
abstract：:The effects of Bay K8644, a Ca2+ channel agonist, on the mechanical and electrical properties of frog skeletal muscle fibers were investigated. At relatively low concentrations, such as 10(-6) and 10(-5) M, Bay K8644 significantly potentiated the maximum amplitudes of twitch responses, and this effect was not reversed...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y94-173
更新日期：1994-10-01 00:00:00
abstract：:The novel biological effect of statins in alleviating myocardium fibrosis following infarction has been increasingly recognized, yet the underlying mechanisms are not fully understood. The purpose of this study was to characterize the effect of simvastatin on myocardial fibrosis and collagen I deposition in the non-in...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y10-075
更新日期：2010-11-01 00:00:00
abstract：:The intraperitoneal administration of insulin has been recommended because it was found to effectively control the plasma glucose level. Several authors have suggested that intraperitoneal insulin administration may be more "physiological" and therefore preferable because the insulin is absorbed into the portal venous...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y86-036
更新日期：1986-03-01 00:00:00
abstract：:Ah receptor in hepatic cytosols from adult cynomolgus monkeys (Macaca fasicularis) was identified and quantitated by its binding of the highly toxic chemical 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and the carcinogens 3-methylcholanthrene, benzo[a]pyrene, and dibenz[a,h]anthracene. The concentration of Ah receptor ...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y84-216
更新日期：1984-10-01 00:00:00
abstract：:Several studies suggest that heat stress affects placental functions including uteroplacental circulation, subsequently leading to pregnancy failure and birth weight reduction. To clarify the involvement of endothelin and placental prostaglandin (PG) systems in the uteroplacental circulation during heat stress, we exa...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y04-011
更新日期：2004-04-01 00:00:00
abstract：:The effects of U46619, a thromboxane mimic, on cytosolic Ca2+ concentration and platelet aggregation were determined in human platelets. Cytosolic Ca2+ concentration was determined by Quin-2 fluorescence and platelet aggregation quantitated with an aggregometer. Addition of U46619 (1 x 10(-7) M) to the platelet suspen...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y91-088
更新日期：1991-05-01 00:00:00
abstract：:The metabolic effect of intravenous infusion of ammonium chloride (60 mumol/(kg body weight.min] was compared in five sheep before and after adrenal denervation. Adrenal denervation completely abolished the hyperglycemic effect of ammonium chloride, diminished the rise of pyruvate and lactate concentration, and failed...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y89-168
更新日期：1989-09-01 00:00:00
abstract：:The disruption to glucose homeostasis upon glucocorticoid (GC) treatment in adult male rats has not been fully characterized in older rats or in females. Thus, we evaluated the age- and gender-related changes in glucose homeostasis in GC-treated rats. We injected male and female rats at 3 months and 12 months of age w...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/cjpp-2014-0259
更新日期：2014-10-01 00:00:00
abstract：:The force generated by tracheal spirals and lung parenchymal strips from normal and ovalbumin-sensitized guinea pigs was measured in vitro, after challenge with histamine, carbachol, leukotriene (LT) C4, LTD4, or a prostaglandin endoperoxide analog (U-44069). The responses and sensitivity of airway tissues to the abov...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y83-133
更新日期：1983-08-01 00:00:00
abstract：:Our previous results showed that addition of agonists, such as vasopressin and angiotensin, added to incubation medium with freshly excised rat atria caused marked release of atrial natriuretic factor (ANF). This release was in the form of prohormone rather than active peptide. Since others had difficulty reproducing ...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y89-218
更新日期：1989-10-01 00:00:00
abstract：:The effect of chlorpromazine on subcellular biosynthesis, hydrolysis, and transfer of lipids and liponucleotides participating in the biosynthesis of polyglycerophosphatides in guinea pig liver was studied. Chlorpromazine showed an apparent stimulation of accumulation of phosphatidic acid and CDP-diglycerides in micro...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y87-064
更新日期：1987-03-01 00:00:00
abstract：:The potential of nickel chloride to prevent streptozotocin-induced hyperglycemia was tested in rats in vivo. To induce diabetes, streptozotocin (100 mg/kg body weight) was injected as a single dose. Streptozotocin treatment resulted in a significant decrease in plasma insulin and ceruloplasmin, and pancreatic Cu, prot...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y88-104
更新日期：1988-05-01 00:00:00
abstract：:A hydroperoxide compound structurally related to acetylsalicylic acid, 3-hydroperoxy-3-methylphthalide, inhibits both the first and second phases of adenosine diphosphate induced, biphasic, human platelet aggregation. This occurs over the same concentration range (0.05-0.5 mM) that acetylsalicylic acid inhibits second...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y84-053
更新日期：1984-03-01 00:00:00
abstract：:Molecular mechanisms by which exercise exerts cardiovascular benefits are poorly understood. Exercise-induced increase of endothelial NO synthase (eNOS) phosphorylation through the protein kinase Akt has been shown to be a key mechanism underlying the beneficial effect of exercise in coronary artery disease patients. ...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y10-107
更新日期：2011-01-01 00:00:00
abstract：:The hemodynamic effects of the combination of clonidine and propranolol were studied in conscious rats with portal hypertension owing to secondary biliary cirrhosis. Pressure and blood flow measurements (radioactive microsphere method) were performed in three groups of eight rats before and after drug administration. ...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y89-219
更新日期：1989-10-01 00:00:00
abstract：:Microelectrode and mechanical studies were performed with isolated guinea pig myocardium (right ventricular free walls and papillary muscles) to examine the effects of platelet-activating factor (PAF) and lysophosphatidylcholine (LPC). Low concentrations of PAF (10(-8) to 10(-6) M, a range equivalent to the blood conc...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y89-107
更新日期：1989-06-01 00:00:00
abstract：:Space travelers experience anorexia and body weight loss in a microgravity environment, and microgravity-like situations cause changes in hypothalamic activity. Hypothalamic melanocortins play a critical role in the regulation of metabolism. Therefore, we hypothesized that microgravity affects metabolism through alter...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/Y09-074
更新日期：2009-10-01 00:00:00
abstract：:Hepatotoxicity and nephrotoxicity are important drawbacks of cisplatin. The objective of this study is to evaluate the ability of ambroxol in 2 different doses (35 and 70 mg/kg, i.p.) to protect liver and kidney from damage induced by a single dose of cisplatin (10 mg/kg, i.p.) in comparison with N-acetylcysteine (250...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/cjpp-2018-0528
更新日期：2019-01-01 00:00:00
abstract：:The isolated brachial spinal cord of the mudpuppy is useful for studies of neural networks underlying forelimb locomotion, but information about its anatomy is scarce. We addressed this issue by combining retrograde labeling with fluorescent tracers and confocal microscopy. Remarkably, the central region of gray matte...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y04-055
更新日期：2004-08-01 00:00:00
abstract：:The effects of acute hypercapnia on human thermoregulation during cold exposure were investigated by immersion of eight male subjects to the neck in a 15 degrees C water bath until their core temperatures dropped to 35 degrees C or until 1 h of immersion had elapsed. Air was inspired throughout each experiment, with t...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 临床试验,杂志文章
doi：10.1139/y94-037
更新日期：1994-03-01 00:00:00
abstract：:Neuropeptide Y (NPY), one of the most abundant peptides in rat and human brains, appears to act in the hypothalamus to stimulate feeding. It was first suggested that the NPY Y1 receptor (Y1R) was involved in feeding stimulated by NPY. More recently a novel NPY receptor subtype (Y5R) was identified in rat and human as ...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：
更新日期：2000-02-01 00:00:00
abstract：:The influence of external potassium Ko and tetraethylammonium on the cellular K content of hypoxic myocardium was investigated. Perfused rabbit hearts were submitted to 60 min hypoxia in medium containing 5 mM K throughout or either low (1.5 mM) or high (10 mM) K during the last 20 min of hypoxia. Paced electrical act...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y87-138
更新日期：1987-05-01 00:00:00
abstract：:The alcohol oxidase membrane technique is available for measurement of ethanol in commercial fluids. In this paper we examined its usefulness for cat and human blood in comparison with gas-liquid chromatography (GLC). The membrane method proved to be simple, reproducible, accurate, and inexpensive. Analysis took 1-2 m...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y88-052
更新日期：1988-04-01 00:00:00
