Abstract：
:The relationship between the postsynaptic alpha 1-adrenoceptor reserve and the sensitivity of vasoconstriction induced by alpha-adrenoceptor agonists to the dihydropyridine Ca2+ entry blocker nifedipine was investigated in isolated muscle strips of dog mesenteric artery (DMA) and saphenous vein (DSV). The amplitudes of the contractile responses of DMA induced by phenylephrine were the same as those in DSV in the presence and in the absence of extracellular Ca2+. The use of 3 x 10(-9) M phenoxybenzamine to irreversibly block the alpha 1-adrenoceptors revealed a marked difference in the size of the alpha 1-adrenoceptor reserve between DMA (40%) and DSV (7%). In spite of a larger receptor reserve, the contractile responses induced by phenylephrine in DMA were more sensitive to nifedipine compared with those in DSV. These results suggest that the postsynaptic alpha 1-adrenoceptor reserve in vascular smooth muscle, at least in DMA and DSV, does not play an important role in buffering the inhibitory effect of nifedipine on the contractile response to a full agonist of alpha 1-adrenoceptors. Other factors, such as the difference in the membrane depolarizing effect, the ability to utilize intracellular Ca2+ for contraction, and the possible existence of alpha 1-adrenoceptor subtypes, may contribute to the different inhibitory effects of nifedipine on these blood vessels.
journal_name
Can J Physiol Pharmacoljournal_title
Canadian journal of physiology and pharmacologyauthors
Guan YY,Kwan CY,Daniel EEdoi
10.1139/y90-203subject
Has Abstractpub_date
1990-10-01 00:00:00pages
1346-50issue
10eissn
0008-4212issn
1205-7541journal_volume
68pub_type
杂志文章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：:The present study was designed to evaluate the role of endothelial NO in the hemodynamics and vascular changes that occur in heart failure following myocardial infarction in rats. Left ventricular systolic pressure (LVSP), mean blood pressure (MBP), aortic morphology (media thickness) and reactivity were evaluated in ...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y04-038
更新日期：2004-06-01 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：:The precise role of microglia in stroke and cerebral ischemia has been the subject of debate for a number of years. Microglia are capable of synthesizing numerous soluble and membrane-bound biomolecules, some known to be neuroprotective, some neurotoxic, whereas others have less definitive bioactivities. The molecular...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章,评审
doi：10.1139/Y05-143
更新日期：2006-01-01 00:00:00
abstract：:We have previously demonstrated a 40% increase in myocardial blood flow (MBF) during hypercapnia but no significant decrease of MBF during hypocapnia. The present study was undertaken to evaluate if epinephrine infusion, which increases both myocardial oxygen consumption (MVo2) and myocardial performance, might influe...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y86-006
更新日期：1986-01-01 00:00:00
abstract：:We examined the effects of long-term streptozotocin (STZ) diabetes and its treatment by intensive insulin therapy (IIT) or pancreatic islet transplantation on pulmonary pressor and depressor responses and segmental resistance profiles in female Wistar-Furth rats. Pulmonary vascular reactivity was examined using isolat...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/cjpp-76-4-407
更新日期：1998-04-01 00:00:00
abstract：:Biochemical studies using highly condensed Xenopus sperm chromatin and protein extracts prepared from multiple systems have lead to the identification of conserved proteins involved in chromosome decondensation. However, mutations to these proteins are unavailable as the systems used are not amenable to genetic studie...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y05-042
更新日期：2006-03-01 00:00:00
abstract：:Adult rats treated with high doses of streptozocin became progressively more hyperglycemic during the first month of the diabetic condition. Treatment of these rats with the sulfonylurea glyburide halted, and in some cases, reversed this process in a high percentage of the diabetics. Associated with the glyburide-medi...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y88-242
更新日期：1988-12-01 00:00:00
abstract：:alpha-Fluoromethylhistidine, a histidine decarboxylase inhibitor, induced a significant depletion in the hypothalamic, midbrain, and cortical brain histamine amounts in 12- and 3-month-old rats. In all three brain regions the most evident depletion occurred 2 h after treatment. In both groups of rats midbrain histamin...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y87-339
更新日期：1987-10-01 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：:To determine whether the renal responses to atrial natriuretic factor (ANF) are altered in the diabetic state, the diuretic and natriuretic responses to ANF (0.25 microgram.kg-1.min-1, i.v.) were measured in streptozotocin (STZ) induced diabetic (DIA) rats. Urine flow and sodium excretion were measured before and afte...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y90-060
更新日期：1990-03-01 00:00:00
abstract：:Normal penile erectile function is dependent on arterial adequacy, appropriate venous occlusion, neurohumoral factors, and finally the relaxation of penile cavernous trabecular smooth muscle. The present experiments were designed to test whether compounds related to endothelium-derived relaxing factor have a role in p...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y89-014
更新日期：1989-01-01 00:00:00
abstract：:Administration of naloxone to morphine-dependent rats results in an elevation of tail skin temperature and a fall in core temperature. Previous studies have demonstrated a role of the adrenal gland in the thermal responses that accompany morphine withdrawal in the rat. In the present study, experiments were designed t...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y92-151
更新日期：1992-08-01 00:00:00
abstract：:2,4-Dinitrophenol, pentobarbital, thiopental, methoxyflurane, and halothane more often antagonized the facilitatory effects of substance P than of acetylcholine on the activity of spinal dorsal horn neurons (of unanesthetized decerebrated and spinalized cats) as well as interpeduncular and cerebral cortical cells (of ...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y78-082
更新日期：1978-06-01 00:00:00
abstract：:The leaves and bark of Cassia glauca Lam., a glabrous tree in the family Fabaceae, are used in folk medicine for the treatment of diabetes. The aim of this study was to investigate the antidiabetic activity of the aqueous extract of C. glauca bark. The various parameters that were studied in treated or untreated normo...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/Y09-121
更新日期：2010-02-01 00:00:00
abstract：:Endometritis is one of the main diseases that harms the dairy cow industry. Tanshinone IIA (TIIA), a fat-soluble alkaloid isolated from Salviae miltiorrhizae, has been reported to have potent anti-inflammatory properties. However, the anti-inflammatory effects of TIIA on a mouse model of lipopolysaccharide (LPS)-induc...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/cjpp-2015-0003
更新日期：2015-11-01 00:00:00
abstract：:Systolic blood pressure was measured weekly in conscious and in anesthetized female Sprague-Dawley (SD) and Wistar-Furth (W/Fu) rats following adrenal enucleation, unilateral nephrectomy, and the imposition of a high salt intake. SD rats quickly developed adrenal-regeneration hypertension (ARH) which progressed rapidl...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y78-165
更新日期：1978-12-01 00:00:00
abstract：:The goal of the present study was to investigate the formation of portacaval shunts in a new experimental model of chronic portal hypertension, portal vein stenosis in the cat. The procedure gradually occluded the portal vein by use of an Ameroid constrictor around the portal vein. After 4 weeks, the portal vein was c...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y93-098
更新日期：1993-09-01 00:00:00
abstract：:Cyclopia subternata is a medicinal plant commonly used in traditional medicine to relieve pain. In this study, we investigated the antiseptic effects and underlying mechanisms of vicenin-2 and scolymoside, which are 2 active compounds from C. subternata that act against high mobility group box 1 (HMGB1)-mediated septi...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/cjpp-2015-0021
更新日期：2015-08-01 00:00:00
abstract：:ER-α and ER-β agonist 17β-estradiol is reported to attenuate cardiac hypertrophy. Tamoxifen is a selective estrogen receptor modulator. Hence, the objective of this study was to investigate the effects of tamoxifen in myocardial infarction. For this, tamoxifen was administered to Sprague-Dawley rats for 1-14 days, and...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/cjpp-2013-0348
更新日期：2014-10-01 00:00:00
abstract：:Temporary block of glycolysis by 2-deoxy-D-glucose (2-DG) reversibly suppresses synaptic transmission in the CA1 region of hippocampal slices. Recovery of responses is followed by a sustained potentiation of field excitatory postsynaptic potentials (EPSPs) (2-DG-LTP). To investigate the mechanisms involved in this typ...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：
更新日期：1997-05-01 00:00:00
abstract：:It has been reported that the intraportal infusion of glutamine in Munich-Wistar rats will cause depression of renal perfusion and the urinary excretion of salt and water. We have attempted to reproduce these findings in anaesthetized dogs. L-Glutamine was infused at doses between 120 and 150 mumol/min into the portal...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y92-201
更新日期：1992-10-01 00:00:00
abstract：:We examined the interaction of smooth muscle myosin with alpha-actin and beta-actin isoforms during the contraction of A7r5 smooth muscle cells and rat aortic smooth muscle. The techniques of confocal microscopy and fluorescence resonance energy transfer (FRET) analysis were utilized in examining A7r5 cells and rat ao...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y09-008
更新日期：2009-05-01 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：:In the rat, prolonged enteral or parenteral alimentation with a high-carbohydrate diet results in hyperinsulinemia, which is substantially greater with the parenteral route. Supplementing the parenteral infusate with porcine gastric inhibitory polypeptide (GIP) to approximate plasma immunoreactive GIP levels achieved ...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y89-175
更新日期：1989-09-01 00:00:00
abstract：:The aim of this study was to investigate the effects of melatonin on rat gastric fundus smooth muscle. Melatonin (10(-4) to 10(-3) M) had no effect on the basal tone of gastric smooth muscle. After precontraction with carbachol (10(-6) M) or serotonin (10(-7) M), melatonin caused a concentration dependent inhibitory a...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：
更新日期：2000-10-01 00:00:00
abstract：:This study aimed to investigate the anti-depressant effect of hesperidin (Hsp) in streptozotocin (STZ)-induced diabetic rats. Additionally, the effect of Hsp on hyperglycaemia, oxidative stress, inflammation, brain-derived neurotrophic factor (BDNF), and brain monoamines in diabetic rats was also assessed. The Wistar ...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/cjpp-2014-0281
更新日期：2014-11-01 00:00:00
abstract：:The validity of a Hodgkin-Huxley type voltage-dependent inactivation of slow inward Ca current (Isi) was tested in frog heart using a computer simulation. The time course of Isi was calculated during the development of a frog atrial action potential (AP). With a time constant of inactivation (tauf) of 55 ms at a membr...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y82-172
更新日期：1982-09-01 00:00:00
abstract：:The vestibulo-ocular and vestibulo-collic reflexes are well-studied sensorimotor systems with dynamic properties that have been successfully modeled. Recently proposed matrix and tensorial models attempt to describe the spatial organization of these reflexes in three dimensions. Here we describe experiments that test ...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y88-083
更新日期：1988-04-01 00:00:00
abstract：:Acute dose--response studies were conducted to determine if ethosuximide had anticonvulsant activity against seizures evoked by stroboscopic stimulation of epileptic fowl and to correlate the observed effects with the concentration of the drug in the plasma. Ethosuximide, in doses that produced mean plasma concentrati...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y78-141
更新日期：1978-10-01 00:00:00
