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 in the presence of the calcium channel antagonist nitrendipine. At higher concentrations, such as 10(-4) M, Bay K8644 depressed the amplitudes of twitch responses, and nitrendipine did not change this effect. At all concentrations, Bay K8644 greatly reduced the area under the tetanic force versus time curve, and this effect was not modified by the concomitant application of Bay K8644 and nitrendipine. Intracellular recordings revealed that the depressing effect of Bay K8644 on tetanic contractions was due to the blockade of sodium action potentials. In conclusion, the present results suggest that the modulation of twitch responses by calcium channel agonist and antagonists, at the concentration range used, is not related to the expected modulation of voltage-sensitive slow calcium channels in frog skeletal muscle fibers, and tetanic contractions are depressed by the calcium channel agonist Bay K8644 through its effect on sodium channels.
journal_name
Can J Physiol Pharmacoljournal_title
Canadian journal of physiology and pharmacologyauthors
Oz M,Frank GBdoi
10.1139/y94-173subject
Has Abstractpub_date
1994-10-01 00:00:00pages
1220-5issue
10eissn
0008-4212issn
1205-7541journal_volume
72pub_type
杂志文章abstract：:Carbon monoxide (CO), a vasodilator, has been implicated as an activator of soluble guanylyl cyclase (sGC) to effect smooth muscle relaxation; however, this idea has not received universal support. The purpose of this study was to examine the effects of the sGC inhibitor 1H-[1,2,4]oxadiazolo[4,3-alpha]quinoxalin-1-one...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：
更新日期：1997-08-01 00:00:00
abstract：:Measurements of the presynaptic fiber volley (PSFV), the population excitatory postsynaptic potential (EPSP), and the extracellular pH in the dendritic CA1 layer of rat hippocampal slices were used to evaluate the effects of lactacidosis on central synaptic transmission. Replacement of NaCl with sodium lactate (up to ...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y90-026
更新日期：1990-02-01 00:00:00
abstract：:Although chronic cocaine use is cardiotoxic, its use remains problematic in athletics. Hence adaptive changes induced in the heart by superimposing chronic cocaine use on an exercise training are of interest but remain poorly understood. Therefore this study investigated the effects of cocaine treatment combined with ...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y94-001
更新日期：1994-01-01 00:00:00
abstract：:The physiological action of alpha bungarotoxin in the central nervous system of the horseshoe crab Limulus polyphemus was investigated. Two types of effects were produced by the toxin. The predominant effect was an inhibition of spontaneous activity. However, in some instances alpha bungarotoxin caused a stimulation o...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y81-023
更新日期：1981-02-01 00:00:00
abstract：:The effect of a novel antianginal agent, molsidomine (N-ethoxycarbonyl-3-morpholinosydnonimine) (SIN-10) and its metabolites, 3-morpholinosydnonimine (SIN-1) and N-nitroso-N-morpholinoaminoacetonitrile (SIN-1A) on isolated dog blood vessels were investigated. SIN-1 and SIN-1A elicited a concentration-dependent relaxat...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y83-159
更新日期：1983-09-01 00:00:00
abstract：:Chronically hypoxic rats (exposed to 5000 m elevation for 3 weeks) develop pulmonary hypertension (PH) that is reversed upon return to normoxia and is blocked by bradykinin (BK) antagonist B9430 treatment (100 microg/kg s.c. three times per week). Treatment of rats with both the synthetic VEGF receptor-1/2 antagonist ...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y02-047
更新日期：2002-04-01 00:00:00
abstract：:The blood volume of anesthetized rats was expanded acutely by 33% with donor blood while a caval snare was gradually tightened so that right atrial pressure (RAP) was prevented from rising (n = 6). In control experiments (n = 5) an aortic snare was used to hold mean arterial blood pressure near the values found in the...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y84-131
更新日期：1984-07-01 00:00:00
abstract：:We compared some of our latest experiments on blood pressure control and erythrocytosis in spontaneously hypertensive rats with Gaar's computer-simulated studies, which suggest that erythrocytosis is a key to understanding the hemodynamic changes in hypertension. We tested two of Gaar's several predictions: (i) periph...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y94-096
更新日期：1994-06-01 00:00:00
abstract：:Redistribution of blood flow away from resting skeletal muscles does not occur during anemic hypoxia even when whole body oxygen uptake is not maintained. In the present study, the effects of sympathetic nerve stimulation on both skeletal muscle and hindlimb blood flow were studied prior to and during anemia in anesth...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y88-019
更新日期：1988-02-01 00:00:00
abstract：:The aim of this study was to demonstrate that within a population of healthy men (n = 15) of varying levels of aerobic fitness (VO2max = 36-74 mL.kg-1.min-1), (i) there are high and low responders with respect to carotid-cardiac baroreflex responsiveness, despite similar baseline heart rates (HRs) both at rest and dur...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 临床试验,杂志文章
doi：10.1139/y95-014
更新日期：1995-01-01 00:00:00
abstract：:The ontogenic study of the hepatic biotransformation enzymes revealed the early development of both oxidative and conjugative enzymes in male chickens ranging in age from 3 to 12 weeks. Although the rate of microsomal cytochrome P450 reactions progressively increased during the first 9 weeks, it decreased thereafter. ...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：
更新日期：1996-01-01 00:00:00
abstract：:Although mitochondrial transcription factor A (TFAM) is a protective component of mitochondrial DNA and a regulator of calcium and reactive oxygen species (ROS) production, the mechanism remains unclear. In heart failure, TFAM is significantly decreased and cardiomyocyte instability ensues. TFAM inhibits nuclear facto...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/cjpp-2016-0718
更新日期：2018-02-01 00:00:00
abstract：:The recognition of chylomicrons as dietary lipid transporters dates back to more than 70 years and marks a milestone in lipoprotein history. Conventionally, three phases constitute the process of absorption of exogenous fat: intraluminal, intestinal, and delivery. The intraluminal phase includes chemical hydrolysis by...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章,评审
doi：10.1139/y92-052
更新日期：1992-04-01 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 airway smooth muscle from asthmatic airways produces increased amounts and an altered composition of extracellular matrix proteins. The extracellular matrix can in turn influence the phenotype and function of airway smooth muscle cells, affecting the biochemical, geometric, and mechanical properties of the airway ...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章,评审
doi：10.1139/Y07-050
更新日期：2007-07-01 00:00:00
abstract：:In addition to cytostatic treatment and surgery, the most common cancer treatment is gamma radiation. Despite sophisticated radiological techniques however, in addition to irradiation of the tumor, irradiation of the surrounding healthy tissue also takes place, which results in various side-effects, depending on the a...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章,评审
doi：10.1139/cjpp-2015-0006
更新日期：2015-09-01 00:00:00
abstract：:Malnutrition and inflammation are associated with end-stage renal disease (ESRD). Interleukin (IL)-6 and tumor necrosis factor alpha (TNF-alpha) powerfully predict death from cardiovascular disease. The aim of our study was to establish an association between markers of inflammation and parameters of malnutrition in p...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/Y08-018
更新日期：2008-04-01 00:00:00
abstract：:Rats fed a polychlorinated biphenyl (PCB) mixture in a high- or low-iodine diet (HID or LID respectively) for 15 days had thyroid enlargement, low serum thyroxine (T4), and high serum thyrotropin concentrations. Although binding of thyroid hormones to serum proteins was reduced in PCB-fed animals, the free T4 index (r...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y77-041
更新日期：1977-04-01 00:00:00
abstract：:The effect of adrenaline on the membrane transport of 3-methylglucose was studied in perifused isolated rat left atria that had been fully arrested. In this preparation a high concentration of adrenaline stimulated and a low one decreased sugar transport. The stimulatory effect was strongly inhibited by the beta-adren...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y76-099
更新日期：1976-10-01 00:00:00
abstract：:Exercise is a powerful therapy for preventing the onset of and slowing the progression of cardiovascular disease. Increased shear stress during exercise improves vascular homeostasis by both decreasing reactive oxygen species and increasing nitric oxide bioavailability in the endothelium. While these observations are ...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章,评审
doi：10.1139/cjpp-2013-0486
更新日期：2014-07-01 00:00:00
abstract：:Fluctuations in the concentrations of cortisol and progesterone in fetal plasma, maternal plasma, and amniotic and allantoic fluids were measured in samples taken at 10-min intervals over a 90-min period from three groups of sheep sampled at different times during late pregnancy. During the last 30 days of gestation t...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y81-041
更新日期：1981-03-01 00:00:00
abstract：:Hepatocellular carcinoma (HCC) is one of the most life-threatening cancers. The present study was designed to chronologically analyze the HCC chemically induced by diethylnitrosamine (DEN) in male Wistar rats during a 27-week period. DEN was given to rats in drinking water (100 mg/L) to induce HCC. In the present stud...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/cjpp-2017-0413
更新日期：2017-12-01 00:00:00
abstract：:Mechanisms leading to ifosfamide (IF)-induced renal damage have not been fully elucidated. Recent work suggests that localized renal tubular metabolism of IF and the production of the nephrotoxic chloroacetaldehyde may lead to nephrotoxicity. Presently no pharmacological method to reduce IF nephrotoxicity has been ide...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y05-036
更新日期：2005-06-01 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：:In many species systemic toxicity of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is manifested by a generalized wasting syndrome accompanied by a variety of specific organ changes including atrophy of the thymus and spleen. TCDD toxicity in most tissues is thought to be mediated by the Ah receptor. Although the spleen ...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y89-095
更新日期：1989-06-01 00:00:00
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：:Kinins are the endogenous ligands of the constitutive B2 receptor (B2R) and the inducible B1 receptor (B1R). Whereas B2R prevents insulin resistance, B1R is involved in insulin resistance and metabolic syndrome. However, the contribution of B1R in type 2 diabetes associated with obesity remains uncertain. The aim of t...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/cjpp-2016-0063
更新日期：2016-07-01 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：:Neonatal hyperthyroidism in rats induced by daily administration of L-triiodothyronine for 30 days since birth resulted in a significant rise in mobility and the metabolism of brain norepinephrine and dopamine. Whereas administration of lithium carbonate (60 mg/kg ip) to normal rats for 6 days produced no effect on sp...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y77-070
更新日期：1977-06-01 00:00:00
abstract：:The presence of different receptor populations within a given brain area can be effectively evaluated via the local injections of defined receptor agonists and antagonists. Using this approach, it has become evident that the nucleus basalis - cortical cholinergic pathway possesses an inhibitory GABAergic input to the ...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y86-053
更新日期：1986-03-01 00:00:00
