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 30 mM) was found not to affect the PSFV; however, the EPSP was reversibly suppressed. Sodium citrate, with added CaCl2 to adjust for Ca2+ chelation, had the same effect as sodium lactate. Addition of lactic acid influenced the PSFV only when, at a concentration of 30 mM, the extracellular pH dropped to 6.6 or lower. With lactic acid concentrations of up to 20 mM, which produced pH levels of 6.8 in the slice, effects on the EPSP were reversible. However, 30 mM lactic acid suppressed both the PSFV and EPSP irreversibly. These results show that synaptic transmission is much more susceptible to lactacidosis than presynaptic axonal transmission. They also show that high levels of lactate, albeit causing suppression of synaptic transmission, do not cause irreversible damage. However, acidosis associated with lactic acid release may damage synaptic transmission irreversibly.
journal_name
Can J Physiol Pharmacoljournal_title
Canadian journal of physiology and pharmacologyauthors
Walz W,Harold DEdoi
10.1139/y90-026subject
Has Abstractpub_date
1990-02-01 00:00:00pages
164-9issue
2eissn
0008-4212issn
1205-7541journal_volume
68pub_type
杂志文章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：:This study investigated the potential of shikonin as an anticancer agent against liver cancer and an in vitro human hepatoma cancer model system. The HepG2 cell line was the hepatoma cancer model in the present study. The inhibitory effect of shikonin on the growth of HepG2 cells was measured by MTT assay. To explore ...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/Y10-085
更新日期：2010-12-01 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：:Smooth muscle cells exhibit phenotypic and mechanical plasticity. During maturation, signalling pathways controlling actin dynamics modulate contractile apparatus-associated gene transcription and contractile apparatus remodelling resulting from length change. Differentiated myocytes accumulate abundant caveolae that ...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章,评审
doi：10.1139/y05-107
更新日期：2005-10-01 00:00:00
abstract：:There is now evidence for the involvement of four beta-adrenoceptor populations in the regulation of cardiac function by catecholamines. Beta1- and beta2-adrenoceptor stimulation classically produces an increase in contractility. A fourth beta-adrenoceptor, as yet uncloned and designated provisionally as a beta4-adren...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章,评审
doi：
更新日期：2000-09-01 00:00:00
abstract：:Doxepin binds to intact astrocytes in primary cultures. The binding is competitively displaceable by excess cold doxepin and it is pronounced (Bmax = 27 nmol/mg protein) but the affinity is rather low (KD = 30 microM). The binding is inhibited by other antidepressants (amitriptyline, desipramine, tranylcypromine, ipri...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y80-230
更新日期：1980-12-01 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：:The effects of the dopamine type-2 receptor (D-2) antagonist domperidone on pituitary and brain amine concentrations and serum gonadotropin levels in the goldfish were investigated. Domperidone caused a long-lasting, dose-dependent depletion of dopamine in the goldfish pituitary. Pituitary concentrations of 5-hydroxyt...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y91-116
更新日期：1991-06-01 00:00:00
abstract：:Female rats subjected to 48 h of water deprivation drank more than similarly deprived males. There was no sexual difference in the dipsogenic responses to intracellular dehydration produced by intravenous hypertonic NaCl but females drank considerably more than males in response to the extracellular stimuli of hyperon...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y80-179
更新日期：1980-10-01 00:00:00
abstract：:Traumatic brain injury (TBI) is one of the main causes of intellectual and cognitive disabilities. In the clinic it is essential to limit the development of cognitive impairment after TBI. In this study, the effects of gallic acid (GA; 100 mg/kg, per oral, from 7 days before to 2 days after TBI induction) on neurologi...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/cjpp-2014-0546
更新日期：2015-08-01 00:00:00
abstract：:Glucosamine sulfate is a dietary supplement that is marketed as a treatment for osteoarthritis. Recent evidence from animal and cell culture models have suggested that glucosamine treatment can promote the misfolding of proteins and the activation of the unfolded protein response (UPR). We investigated whether glucosa...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/cjpp-2013-0318
更新日期：2014-04-01 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
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：:The heat production (HP), heart rate (HR), respiration rate, rumen motility, and body temperature responses to 2.5-h adrenaline (A) and noradrenaline (NA) intrajugular infusions at 0.00, 0.15, 0.30, 0.60, and 0.90 micrograms.kg-1.min-1 were studied in 10 shorn wethers which had been chronically (3-8 weeks) exposed to ...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y81-150
更新日期：1981-09-01 00:00:00
abstract：:The effects of clofibrate administration (200 mg/kg, po) on somatic growth, plasma levels of lipids, tryptophan, growth hormone (GH), and prolactin (PRL), as well as on brain concentrations of tryptophan and 5-hydroxytryptamine (5-HT) were studied in prepubertal male rats. The drug did not significantly alter ponderal...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y78-039
更新日期：1978-04-01 00:00:00
abstract：:Uroporphyrinogen decarboxylase (UROG-D) activity in the 10,000g supernatant of 17-day-old chick embryo liver homogenates was determined by measuring the conversion of pentacarboxylporphyrinogen I to coproporphyrinogen I. The optimum pH of the enzyme was found to be approximately 6.0 and enzyme activity was found to be...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y89-041
更新日期：1989-03-01 00:00:00
abstract：:The neural connections from the medial prefrontal cortex to the ventral pallidum were investigated in urethane-anesthetized rats. Extracellular recordings were made from 124 spontaneously firing neurons in the ventral pallidum while the medial prefrontal cortex was electrically stimulated. The most frequent response t...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y93-053
更新日期：1993-05-01 00:00:00
abstract：:Transcranial magnetic stimulation over the motor cortex was used to construct a map of the effective sites on the scalp from which short-latency electromyogram responses could be evoked in muscles proximal to either an amputation stump (two subjects) or an ischemically anesthetized forearm (two subjects). At rest, the...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y95-032
更新日期：1995-02-01 00:00:00
abstract：:Thyrotoxicosis, a condition in which there is an excessive amount of circulating thyroid hormones, leads to reduced glycogen content in different tissues. In this study we analyzed the effects of aerobic swimming training on liver, heart, and skeletal muscle glycogen content in experimentally induced thyrotoxicosis. W...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y2012-044
更新日期：2012-05-01 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：: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 inotropic response induced by beta-adrenergic and H1 histaminergic receptor stimulation was characterized in guinea pig left atria by obtaining dose-response relationships for isoproterenol and histamine under various experimental conditions. Conditions (hypothermia, high frequencies of stimulation, and large extr...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y78-147
更新日期：1978-12-01 00:00:00
abstract：:The purpose of this study was to investigate the effects of bosentan, a mixed endothelin receptor A and B subtype antagonist, on myocardial ischemia-reperfusion injury and to explore the influence of the timing of bosentan administration on its cardioprotective effects. Adult rat hearts were perfused by the Langendorf...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y05-014
更新日期：2005-03-01 00:00:00
abstract：:Magnesium probably protects brain tissue against the effects of cerebral ischemia, brain injury and stroke through its actions as a calcium antagonist and inhibitor of excitatory amino acids. The effects of magnesium sulfate on cerebrovascular permeability to a dye, Evans blue, were studied during insulin-induced hypo...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：
更新日期：2001-09-01 00:00:00
abstract：:A semisynthetic chemical compound, demethyldiisoeugenol, concentration dependently inhibited platelet aggregation and ATP release stimulated by thrombin (0.1 U/mL), platelet-activating factor (2 ng/mL), arachidonic acid (100 microM), collagen (10 micrograms/mL), and U46619 (1 microM) in rabbit washed platelets. The IC...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/cjpp-74-10-1111
更新日期：1996-10-01 00:00:00
abstract：:Transactivation of epidermal growth factor receptor (EGFR) is a well-documented mechanism by which vasoactive peptides and H2O2 elicit their cellular responses. However, a role for the insulin-like growth factor type-1 receptor (IGF-1R) transactivation in mediating the effects of angiotensin II (Ang II) and H2O2 in va...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章,评审
doi：10.1139/Y06-101
更新日期：2007-01-01 00:00:00
abstract：:The natural history of the disease of the dilated strain Bio TO-2 of cardiomyopathic hamsters (CMH) is not totally characterized. We investigated its hemodynamic and histomorphometric characteristics at 140, 180, 220, 260, and 300 days of age. Forty CMH and 40 controls were investigated (8 at each stage). Mean arteria...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：
更新日期：2001-04-01 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：:Single crab (Callinectes danae) fibers were equilibrated with isotonic, high KCl solutions and were subsequently returned to the control saline. This caused marked swelling of the T tubules. Fibers treated with 100 mM KCl had a 2.5-mV residual depolarization, a 50% decrease in effective membrane resistance (Reff) and ...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y85-144
更新日期：1985-07-01 00:00:00
abstract：:Local microinjections of harmaline evoked sustained rhythmic activity in the inferior olive of decerebrate cats. Harmaline appears to exert its action within restricted areas of the inferior olivary complex: the caudal halves of the dorsal and medial accessory nuclei. Since the highly synchronized activity generated b...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y75-116
更新日期：1975-10-01 00:00:00
