Abstract：
:The interactions of ligands with their receptors and the modulation of those interactions by other ligands are commonly described in the (verbal and mathematical) language of enzymology. While this analogy is appropriate in that velocity-substrate concentration curves and ligand-receptor binding isotherms often conform to similar rectangular hyperbolic relationships, the mathematical and conceptual similarities between the two systems strictly apply only to the simplest cases (absence or presence of a pure competitive inhibitor). To conclude that other classic forms of enzyme inhibition (uncompetitive, noncompetitive, mixed) have their exact mechanistic counterparts in "receptorology" can be misleading if due consideration is not given to the differences between the two types of system (steady-state versus equilibrium). In this communication, it is shown that relating receptor binding mechanisms to enzymological models results in Scatchard plots that are markedly different in appearance from the equivalent Eadie plots displaying enzyme kinetic data for all cases other than those in the absence of inhibitor or in the presence of a purely competitive inhibitor. It follows that receptor binding systems, which do produce inhibition patterns similar to those indicative of uncompetitive, noncompetitive, or mixed inhibition of an enzyme system, must do so through mechanisms that are different from those that produce these effects on enzymes. Consequently, terms such as uncompetitive or noncompetitive inhibition have different meanings when applied to receptors as compared with enzymes.
journal_name
Can J Physiol Pharmacoljournal_title
Canadian journal of physiology and pharmacologyauthors
Tomlinson Gdoi
10.1139/y88-059subject
Has Abstractpub_date
1988-04-01 00:00:00pages
342-9issue
4eissn
0008-4212issn
1205-7541journal_volume
66pub_type
杂志文章abstract：:The synthesis, receptor binding, and agonist activity of a series of truncated atrial natriuretic analogs (ANF) are described. These analogs incorporate two portions of the native 28 amino peptide, the eight amino acids C-terminal to Cys7, and two amino acids from the C-terminus (phenylalanine and arginine), into disu...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y91-240
更新日期：1991-10-01 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：:Diamine oxidase activity was measured in the intestinal mucosa, lymph, and in the serum of rats, to determine whether histamine, a substrate of diamine oxidase, liberates this enzyme from its mucosal storage site(s). Histamine induced a sharp rise in intestinal lymph flow, lymph protein, and lymph diamine oxidase, las...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y83-053
更新日期：1983-04-01 00:00:00
abstract：:Sequestration of nitric oxide (NO) by subcellular fractions isolated from bovine pulmonary arterial medial layer (BPA) and rabbit platelets (RP) was studied utilizing a novel chemiluminescence--headspace gas technique. Sequestration in all fractions was similarly rapid (5 min) and remained constant for at least 30 min...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y93-142
更新日期：1993-12-01 00:00:00
abstract：:To investigate the capacity of efferent sympathetic neurons to modulate the failing heart, stellate ganglion stimulation was performed in dogs with biventricular heart failure induced by rapid ventricular pacing (240 beats/min) for 4-6 weeks. Less noradrenaline was released from cardiac myoneural junctions into corona...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：
更新日期：1996-09-01 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：:Pioglitazone (Pio) and swimming exercise (SE) are insulin sensitisers. This investigation was suggested because of the significant side effects associated with Pio treatment in metabolic syndrome (MetS). This study was, therefore, designed to investigate the preventive role of Pio treatment and SE in terms of efficien...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/cjpp-2013-0043
更新日期：2014-02-01 00:00:00
abstract：:The effect of oleate (0.3 and 1.2 mM) and the combined effect of beta-hydroxybutyrate (4 and 8 mM) and acetoacetate (1 and 2 mM) on rates of lipolysis (glycerol output) was determined with calcium-tolerant myocytes isolated from the hearts of normal rats and hearts from acutely (2-3 days; 100 mg/kg streptozotocin) dia...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y90-176
更新日期：1990-09-01 00:00:00
abstract：:Opioid and N-methyl-d-aspartate (NMDA) receptors mediate different effects of fluoxetine. We investigated whether opioid and NMDA receptors are involved in the protective effect of fluoxetine against the behavioral despair induced by acute physical stress in male mice. We used the forced swimming test (FST), tail susp...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/cjpp-2015-0429
更新日期：2016-06-01 00:00:00
abstract：:In rats anesthetized with alpha-chloralose, doses of 0.1, 0.5, and 1 g/kg of ethanol produced an upward shift of baroreflex curves constructed by plotting the heart rate response against mean arterial pressure following evoked rises in mean arterial pressures by phenylephrine or angiotensin II. Whereas the upward shif...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y87-134
更新日期：1987-05-01 00:00:00
abstract：:Microiontophoretic applications of ibotenate, an amino acid analogue of glutamate, evoked biphasic responses from single dorsal horn interneurones of the cat spinal cord, i.e., an initial increase in the firing rate followed by a sustained depression of spontaneous firing. A reduced cell sensitivity to excitatory amin...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y77-131
更新日期：1977-08-01 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：:Since human thermoregulation at rest is altered by cold exposure, it was hypothesized that physical training under cold conditions would alter thermoregulation. Three groups (n = 8) of male subjects (mean age 24.3 +/- 0.9 years) were evaluated: group T (interval training at 21 degrees C), group CT (interval training a...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y02-109
更新日期：2002-09-01 00:00:00
abstract：:The effects of haloperidol, an antipsychotic butyrophenone, on excitability and action potential production in frog's sartorius muscle fibers were studied. This drug produced a local-anestheticlike effect which developed slowly over 1 to 5 h with lower concentrations (2.7 to 5.3 X 10(-6 M) but was completely reversed ...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y77-066
更新日期：1977-06-01 00:00:00
abstract：:The precise neurobiological mechanisms of tramadol abuse underlying the cognitive function are still unknown. The aim of the present study was to examine the possible effects of intra-CA1 injections of N-methyl-d-aspartate (NMDA), a glutamate NMDA receptor (NMDAR) agonist, and d,l-2-amino-5-phosphonopentanoic acid (DL...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/cjpp-2017-0228
更新日期：2018-01-01 00:00:00
abstract：:The isolated human vas deferens (HVD) has been the subject of a limited number of pharmacological studies. Furthermore, it has not been established whether the local or general anesthetics used in obtaining the HVD affect the responses of this isolated tissue. Therefore, the aim of this study was to determine if the l...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y86-075
更新日期：1986-04-01 00:00:00
abstract：:Myopenia or muscle wasting due to ageing, chronic disease, and various medical interventions has been associated with increased mortality, morbidity, and poorer physical function. Attempts through nutrient and exercise interventions have been made to prevent this deterioration. In addition, while a measure of lean bod...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章,评审
doi：10.1139/cjpp-2012-0304
更新日期：2013-06-01 00:00:00
abstract：:The effect of one bout of acute exercise on impaired glucose metabolism was studied in obese (480 +/- 20 g), untrained rats, at rest (n = 10) and after 60 min of swimming (n = 5). Using the euglycemic, hyperinsulinemic (10 mU.kg-1 x min-1) clamp, glucose clearance rate increased from 7.6 +/- 0.9 at rest to 9.7 +/- 0.5...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y92-208
更新日期：1992-11-01 00:00:00
abstract：:We tested the effects of inhibiting the carbonic anhydrase activity of rat soleus and extensor digitorum longus muscles on the isometric contractile properties and the resistance to fatigue. SOL and EDL muscles from female rats were incubated in vitro in the presence of methazolamide, a specific inhibitor of carbonic ...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y89-103
更新日期：1989-06-01 00:00:00
abstract：:To examine the role of a reduction in plasma volume (PV) on the cardiovascular and thermoregulatory responses to submaximal exercise, ten untrained males (VO2 peak = 3.96 +/- 0.14 L x min(-1); mean +/- SE) performed 60 min of cycle exercise at -61% of VO2 peak while on a diuretic (DIU) and under control (CON) conditio...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：
更新日期：2000-07-01 00:00:00
abstract：:Long-lasting ischemia can result in cell loss; however, repeated episodes of brief ischemia increase the resistance of the heart against deleterious effects of subsequent prolonged ischemic insult and promote cell survival. Traditionally, it is believed that the supply of blood to the ischemic heart is associated with...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章,评审
doi：10.1139/cjpp-2016-0609
更新日期：2017-10-01 00:00:00
abstract：:Lumbar spine and mid-radius bone mineral density was measured repeatedly in 48 postmenopausal women who completed 7 years of taking either a 500 mg x day(-1) calcium supplement (n = 22) or calcium supplementation with hormone replacement therapy. The hormone replacement was either a low dose (n = 15) or a moderate dos...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 临床试验,杂志文章
doi：
更新日期：1999-07-01 00:00:00
abstract：:Altered cytochrome P450-catalyzed metabolism of 17beta-estradiol (E2) and estrone (E1) in the liver and (or) extrahepatic tissues may affect estrogen-sensitive tumorigenesis. We examined the effects of oral treatments of (i) indole-3-carbinol (13C) at 250 or 500 mg/kg or beta-naphthoflavone (beta-NF) at 40 mg/kg of bo...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：
更新日期：2001-06-01 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：: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：: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：:In vivo assessment of treatment efficacy on postinfarct left ventricular (LV) remodeling is crucial for experimental studies. We examined the technical feasibility of serial magnetic resonance imaging (MRI) for monitoring early postinfarct remodeling in rats. MRI studies were performed with a 7-Tesla unit, 1, 3, 8, 15...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y05-115
更新日期：2005-12-01 00:00:00
abstract：:The role of I(K) (delayed rectifier current) and I(f) (hyperpolarization-activated current) in dominant and subsidiary pacemaker ranges was studied in single myocytes isolated from the guinea pig sino-atrial node by means of a perforated patch-clamp technique. In the dominant pacemaker range (approx. -55 to -40 mV), I...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：
更新日期：2001-12-01 00:00:00
abstract：:This review presents, from the author's viewpoint, avenues of histamine research likely to produce new information. One potentially useful approach may be to attempt to relate histamine's function to its occurrence in different body tissues such as the pituitary and hypothalamus, the gastrointestinal mucosa, and the b...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：
更新日期：1985-06-01 00:00:00
abstract：:Nonsteroidal anti-inflammatory drugs are widely used for the treatment of osteoarthritis and rheumatoid arthritis, but their ability to cause gastrointestinal bleeding is a significant limitation to this use. A better understanding of the pathogenesis of gastric and intestinal injury induced by these agents will permi...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章,评审
doi：10.1139/y94-215
更新日期：1994-12-01 00:00:00
