Abstract:
:The whole-cell patch electrode voltage clamp technique was used to study the inactivation properties of the delayed rectifying potassium current of single cultured embryonic chick hepatocytes at 20 degrees C. The potassium current activates maximally within 250-500 ms of membrane depolarization, after which it decays with a monoexponential time course. Both steady-state activation and inactivation are voltage dependent. Steady-state inactivation declines from 100% at -5 mV to 0 near -70 mV. with half inactivation at -41 mV. At the resting potential (EM) of these cells (-21.5 +/- 6.0 mV, n = 36) 6-18% of the IK channels are not inactivated and less than 5% are open. Development and removal of inactivation follow single exponential time courses. The inactivation time constant attains a maximum of around 30 s at -35 mV and is sharply voltage dependent at the EM of these cells. Measurement of EM under current clamp shows random oscillations of 5-10 mV amplitude. We suggest that the voltage- and time-dependent properties of IK, in tandem with a time- and voltage-independent, non-selective current also seen here, would provide the mechanism for a fluctuating EM.
journal_name
Can J Physiol Pharmacoljournal_title
Canadian journal of physiology and pharmacologyauthors
Hill CE,Shrier Adoi
10.1139/y91-110subject
Has Abstractpub_date
1991-06-01 00:00:00pages
739-45issue
6eissn
0008-4212issn
1205-7541journal_volume
69pub_type
杂志文章abstract::In older Aplysia, the central nervous system (CNS) (abdominal ganglion) exerts suppressive and facilitatory control over the peripheral nervous system (PNS) which initially mediates the gill withdrawal reflex and its subsequent habituation evoked by tactile stimulation of the siphon. In young animals, both the suppres...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 杂志文章
doi:10.1139/y79-148
更新日期:1979-09-01 00:00:00
abstract::This study was designed to determine if tonic beta-adrenergic control of plasma renin activity (PRA) during dietary sodium restriction is due to stimulation of renal beta-adrenoceptors, extrarenal beta-adrenoceptors, or both. Experiments were performed in six conscious resting uninephrectomized dogs with chronically i...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 杂志文章
doi:10.1139/y95-171
更新日期:1995-08-01 00:00:00
abstract::This review updates our current knowledge on the regulation of Na+/H+ exchanger, Na+,K+,Cl- cotransporter, Na+,Pi cotransporter, and Na+,K+ pump in isolated epithelial cells from mammalian kidney by protein kinase C (PKC). In cells derived from different tubule segments, an activator of PKC, 4beta-phorbol 12-myristate...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 杂志文章,评审
doi:
更新日期:1999-05-01 00:00:00
abstract::Heparin was introduced into the stomach or duodenum of mice separately in doses of ca. 250 mg/kg. A slight anticoagulant effect in the systemic circulation was detected in whole blood clotting times and factor X inhibition. In contrast to most drugs, more heparin was absorbed from the stomach than from the intestine. ...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 杂志文章
doi:10.1139/y76-084
更新日期:1976-08-01 00:00:00
abstract::Chronic caval dogs with ascites were identified as being natriuretic "responders" or "nonresponders" (delta UNaV less than 20 microequiv./min) following an infusion of atrial natriuretic peptide (ANP) (100 ng.kg-1.min-1). To learn more about the factors modulating tubular resistance to ANP, we attempted to convert res...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 杂志文章
doi:10.1139/y92-120
更新日期:1992-06-01 00:00:00
abstract::The effects of modulators of Ca-ATPase and alkaline phosphatase (AP) activity on placental calcium and phosphorus transfer were studied using the in situ perfused guinea pig placenta. The diuretics ethacrynic acid and furosemide had no significant effect on placental calcium and phosphorus transfer when injected into ...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 杂志文章
doi:10.1139/y83-194
更新日期:1983-11-01 00:00:00
abstract::Glucose utilization and insulin and growth hormone responses were evaluated in eight obese women by three rapid intravenous glucose tolerance tests (IVGTT): during a control period, and after 1 and 3 weeks of a 750 kcal/day protein-lipid diet (1 kcal = 4.1855 kJ). Weight loss averaged 454 g/day during the 1st week and...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 杂志文章
doi:10.1139/y82-044
更新日期:1982-03-01 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 development of the febrile response to E. coli lipopolysaccharide (1.5 micrograms/kg, i.v.) in thyroid-deficient rabbits has been studied. Twenty-eight New Zealand White rabbits weighing 2.1-2.3 kg were used. Hypothyroidism was induced by treatment with propylthiouracil (100 or 200 mg/kg body wt./15 days). Thyroid...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 杂志文章
doi:10.1139/y87-209
更新日期:1987-06-01 00:00:00
abstract::The tau mutation in the golden (Syrian) hamster is a single gene mutation that drastically affects the speed of the circadian clock, in such a way that homozygous mutants have an endogenous circadian period of 20 h (compared with 24 h for wild-type hamsters). While studying the circadian system of tau-mutant hamsters ...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 杂志文章
doi:10.1139/cjpp-2013-0276
更新日期:2014-01-01 00:00:00
abstract::The placental transfer of indomethacin was studied in the rabbit at 30 days of gestation and in the sheep between 120 and 135 days of gestation. Plasma concentrations of indomethacin reached a maximum of 13.7 +/- 1.6 and 10.9 +/- 1.5 microgram/mL in the doe and fetuses, respectively, at 1 h following a maternal subcut...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 杂志文章
doi:10.1139/y81-053
更新日期:1981-04-01 00:00:00
abstract::In order to understand the mechanisms of exercise intolerance and muscle fatigue, which are commonly observed in congestive heart failure, we studied sarcoplasmic reticulum (SR) Ca(2+)-transport in the hind-leg skeletal muscle of rats subjected to myocardial infarction (MI). Sham-operated animals were used for compari...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 杂志文章
doi:10.1139/y04-051
更新日期:2004-07-01 00:00:00
abstract::Tea is perceived as more relaxing than coffee, even though both contain caffeine. L-theanine in tea may account for the difference. Consumed together, caffeine and theanine exert similar cognitive effects to that of caffeine alone, but exert opposite effects on arousal, in that caffeine accentuates and theanine mitiga...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 杂志文章
doi:10.1139/cjpp-2016-0498
更新日期:2017-01-01 00:00:00
abstract::The most commonly observed effect of beta-blockade on cardiovascular function has been a reduction in heart rate both at rest and during exercise. The body attempts to compensate by increasing stroke volume and (or) increasing the extraction of O2 from the blood to maintain O2 delivery to the muscle. This paper examin...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 杂志文章
doi:10.1139/y91-044
更新日期:1991-02-01 00:00:00
abstract::The effects of gallopamil, D600, a methoxy derivative of verapamil, on the mechanical and electrophysiological parameters of isolated guinea-pig myocardial preparations were compared with those of verapamil. Both gallopamil and verapamil produced concentration-dependent negative chronotropic and negative inotropic eff...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 杂志文章
doi:
更新日期:1997-12-01 00:00:00
abstract::The enhancement of the response of an isolated strip of lactating mouse mammary gland to oxytocin, resulting from dilution of the Tyrode solution in which oxytocin is administered, is due to the effects of hypotonicity per se and not to changes in concentration of any of the ions in the bathing solution. Inhibition of...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 杂志文章
doi:10.1139/y79-047
更新日期:1979-03-01 00:00:00
abstract::Aortas were removed from six mature lambs and four sheep and pressure fixed at 100 and 120 mmHg pressure (1 mmHg = 133.322 Pa), respectively, in 10% buffered formalin. The numbers of elastin layers were counted from cross sections at different distances down the aorta, from the distal arch to the iliac bifurcation, an...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 杂志文章
doi:10.1139/y83-016
更新日期:1983-02-01 00:00:00
abstract::Mentoring in academia is often carried out in an informal way depending on individuals and circumstances. I was quite fortunate to make the acquaintance of Professor E.E. Daniel when I was making a transition from my research in entomology to biomedical sciences. Here I recount some of that experience, and describe so...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 杂志文章
doi:10.1139/y05-064
更新日期:2005-08-01 00:00:00
abstract::Sensorimotor mechanisms were studied on the basis of kinematic and electromyographic data as well as the static torque developed by the muscles as a function of joint angle. The latter relationship is known as the torque/angle characteristic. Fast single-joint movement may result from a shift in this characteristic an...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 临床试验,杂志文章,随机对照试验
doi:10.1139/y95-042
更新日期:1995-02-01 00:00:00
abstract::In the wake of demographic change in Western countries, atrial fibrillation has reached an epidemiological scale, yet current strategies for drug treatment of the arrhythmia lack sufficient efficacy and safety. In search of novel medications, atrial-selective drugs that specifically target atrial over other cardiac fu...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 杂志文章,评审
doi:10.1139/cjpp-2017-0024
更新日期:2017-11-01 00:00:00
abstract::Our knowledge of the effects of exercise on the heart is limited by the predominant use of rats as an animal model. The rabbit has many advantages over the rat as an animal model to study. However, little work has characterized its capacity to exercise. The purposes of the present study were to determine if the rabbit...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 杂志文章
doi:10.1139/y90-130
更新日期:1990-07-01 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::Acetylcholine (ACh)-mediated vagal transmission as well as nonneuronal ACh release are considered cardioprotective in pathological situations with increased sympathetic drive such as ischemia-reperfusion and cardiac remodeling. ACh action is terminated by hydrolysis by the cholinesterases (ChEs), acetylcholinesterase,...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 杂志文章
doi:10.1139/cjpp-2019-0565
更新日期:2020-07-01 00:00:00
abstract::Resting membrane potentials and membrane conductances of chick skeletal muscle in culture were determined from the 3rd to the 10th day after plating. The effect of tetraethylammonium (TEA) and of replacement of potassium with caesium on these parameters was investigated. Resting membrane potential (Em) rises during my...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 杂志文章
doi:10.1139/y80-100
更新日期:1980-06-01 00:00:00
abstract::Immunocytochemistry, radioimmunoassay, chromatography, and biological assay using a rabbit isolated duodenal muscle strip preparation were used in attempting to characterize motilin from the rat small intestine. Several different antisera and monoclonal antibodies directed against natural porcine motilin were used. A ...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 杂志文章
doi:10.1139/y90-168
更新日期:1990-08-01 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::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::In the mesenteric circulation of the rat a myogenic autoregulatory system operates at 0.1-0.15 Hz. Negative admittance phase in the region above 0.2 Hz suggested operation of an arterial baroreflex. The present study was designed to test this interpretation and to identify the neurotransmitter involved. In rats anesth...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 杂志文章
doi:10.1139/cjpp-78-1-54
更新日期:2000-01-01 00:00:00
abstract::Epigallocatechin-3-gallate (EGCG), a polyphenol in green tea, is an effective antioxidant and possesses neuroprotective effects. Brain-derived neurotrophic factor (BDNF) and cyclic AMP response element-binding protein (CREB) are crucial for neurogenesis and synaptic plasticity. In this study, we aimed to assess the pr...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 杂志文章
doi:10.1139/cjpp-2016-0333
更新日期:2017-12-01 00:00:00
abstract::In anesthetized dogs, 60-min occlusions of either the proximal (n = 14), distal (n = 8) left circumflex (LCX), or left anterior descending (LAD, n = 10) arteries were followed by reperfusion. Coronary sinus and aortic norepinephrine and epinephrine plasma concentrations were measured. The ventricular arrhythmias were ...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 杂志文章
doi:10.1139/y85-179
更新日期:1985-09-01 00:00:00