Abstract:
:The effects of forskolin, Ro 20-1724, rolipram, and 3-isobutyl-1-methylxanthine (IBMX) on morphine-evoked release of adenosine from dorsal spinal cord synaptosomes were evaluated to examine the potential involvement of cyclic AMP in this action of morphine. Ro 20-1724 (1-100 microM), rolipram (1-100 microM), and forskolin (1-10 microM) increased basal release of adenosine, and at 1 microM inhibited morphine-evoked release of adenosine. Release of adenosine by Ro 20-1724, rolipram, and forskolin was reduced 42-77% in the presence of alpha,beta-methylene ADP and GMP, which inhibits ecto-5'-nucleotidase activity by 81%, indicating that this adenosine originated predominantly as nucleotide(s). Significant amounts of adenosine also were released from the ventral spinal cord by these agents. Ro 20-1724 and rolipram did not significantly alter the uptake of adenosine into synaptosomes. Although Ro 20-1724 and rolipram had only limited effects on the extrasynaptosomal conversion of added cyclic AMP to adenosine, IBMX, a phosphodiesterase inhibitor with a broader spectrum of inhibitory activity for phosphodiesterase isoenzymes, significantly inhibited the conversion of cyclic AMP to adenosine and resulted in recovery of a substantial amount of cyclic AMP. As with the non-xanthine phosphodiesterase inhibitors, IBMX increased basal release of adenosine and reduced morphine-evoked release of adenosine. Adenosine released by IBMX was reduced 70% in the presence of alpha,beta-methylene ADP and GMP, and release from the ventral spinal cord was 61% of that from the dorsal spinal cord. Collectively, these results indicate that forskolin and phosphodiesterase inhibitors release nucleotide(s) which is (are) converted extrasynaptosomally to adenosine.(ABSTRACT TRUNCATED AT 250 WORDS)
journal_name
Can J Physiol Pharmacoljournal_title
Canadian journal of physiology and pharmacologyauthors
Nicholson D,White TD,Sawynok Jdoi
10.1139/y91-133subject
Has Abstractpub_date
1991-06-01 00:00:00pages
877-85issue
6eissn
0008-4212issn
1205-7541journal_volume
69pub_type
杂志文章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 effect of chlorpromazine on subcellular biosynthesis, hydrolysis, and transfer of lipids and liponucleotides participating in the biosynthesis of polyglycerophosphatides in guinea pig liver was studied. Chlorpromazine showed an apparent stimulation of accumulation of phosphatidic acid and CDP-diglycerides in micro...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 杂志文章
doi:10.1139/y87-064
更新日期:1987-03-01 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::Rapamycin, a new antifungal antibiotic, was found to inhibit the immune response in rats. It totally prevented the development of two experimental immunopathies (experimental allergic encephalomyelitis (EAE) and adjuvant arthritis (AA)) and the formation of humoral (IgE-like) antibody. It was about half as potent as c...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 杂志文章
doi:10.1139/y77-007
更新日期:1977-02-01 00:00:00
abstract::Bicuculline methochloride (BMC), applied by microiontophoresis, tends to depolarize spinal motoneurons and lower their input resistance. With approximately equal iontophoretic currents of gamma-aminobutyric acid (GABA) and BMC, there is an almost equal chance of observing no change, a potentiation, or a depression of ...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 杂志文章
doi:10.1139/y77-091
更新日期:1977-06-01 00:00:00
abstract::Our objective was to determine if the ability of an angiotensin-converting enzyme (ACE) inhibitor to attenuate neointima formation in balloon-damaged vessel is expressed in an isolated organ culture model of neointimal growth. In vivo balloon angioplasty in combination with in vitro organ culture was used to produce a...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 杂志文章
doi:
更新日期:1999-10-01 00:00:00
abstract::Changes in dietary omega-6/3 polyunsaturated fatty acids (PUFA) ratios affect anti- and proinflammatory equilibrium. As reperfused myocardial infarction (MI) is an inflammatory pathology that alters the cell integrity of the myocardium but also of other tissues, such as the hippocampus and amygdala, attenuation of the...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 杂志文章
doi:10.1139/Y11-007
更新日期:2011-03-01 00:00:00
abstract::Curare action on nicotinic acetylcholine receptors has a number of facets, of which the best known is competitive antagonism. Here we describe the weak agonist action of 10(-5) M curare on the murine skeletal muscle cell line, G8. Although curare induces no depolarization in G8 cells, single-channel recordings reveal ...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 杂志文章
doi:10.1139/y89-025
更新日期:1989-02-01 00:00:00
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journal_title:Canadian journal of physiology and pharmacology
pub_type: 杂志文章
doi:10.1139/Y09-089
更新日期:2009-12-01 00:00:00
abstract::Although dual endothelin receptor antagonists (ERAs) show great promise for treating various conditions, their propensity to induce liver injury limits their clinical usage. Inflammation and fibrosis are important processes in liver responses to injury and it has been suggested that they and dual ERA-induced liver inj...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 杂志文章
doi:10.1139/cjpp-2019-0649
更新日期:2020-09-01 00:00:00
abstract::In urethane-anaesthetized rats, ion-selective microelectrodes recorded changes in extracellular K+ and Ca2+ concentrations (delta[K+]omicron and delta[Ca2+]omicron) in pyramidal layers of the hippocampus (mostly in area CA1), which were evoked by fimbrial-commissural stimulation. [K+]omicron increased linearly with fr...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 杂志文章
doi:10.1139/y82-243
更新日期:1982-12-01 00:00:00
abstract::The mechanisms of the positive inotropic action of a new synthetic tetrahydroisoquinoline compound, SL-1, were investigated in isolated rat cardiac tissues and ventricular myocytes. SL-1 produced a rapidly developing, concentration-dependent positive inotropic response in both atrial and ventricular muscles and a nega...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 杂志文章
doi:10.1139/y95-727
更新日期:1995-11-01 00:00:00
abstract::This study aimed to test whether boswellic acids add to the antitumor effects of doxorubicin against solid tumors of Ehrlich's ascites carcinoma (EAC) grown in mice, and to investigate the protective effects of boswellic acids against doxorubicin-induced cardiotoxicity. Sixty-four female Swiss albino mice bearing EAC ...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 杂志文章
doi:10.1139/cjpp-2014-0524
更新日期:2015-08-01 00:00:00
abstract::Previous studies have shown that when atrial natriuretic peptide (ANF) is given to anaesthetized dogs with hypovolemic acute pancreatitis, it will produce a diuresis and natriuresis but will not elevate the glomerular filtration rate (GFR). When the same dose of peptide is given to dogs equally hypovolemic (hemorrhage...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 杂志文章
doi:10.1139/y90-099
更新日期:1990-06-01 00:00:00
abstract::Raloxifene (RLX), a selective oestrogen receptor modulator, has oestrogen-agonist effects on bone, lipoproteins, and homocysteine and oestrogen-antagonist activity in the breast and uterus, positioning it as a potential drug for long-term prevention of coronary heart disease in postmenopausal women. To further evaluat...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 临床试验,杂志文章
doi:10.1139/y10-002
更新日期:2010-05-01 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::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 aim of this study was to elucidate the variables of gastroduodenal motility determining gastric emptying. For this purpose the effects of exogenous cholecystokinin, secretin, and gastric inhibitory polypeptide on motility and gastric emptying were studied during a meal. Motility was measured with extraluminal stra...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 杂志文章
doi:10.1139/y87-050
更新日期:1987-03-01 00:00:00
abstract::The exchange of Na+ and K+ in rat red cells at 40% hematocrit incubated in a physiological salt solution containing 1 MM ouabain was monitored with ion-specific glass electrodes. Because this system measures a change in the activity of an ion as a logarithmic function of its preexisting level, delta[K+]o is more accur...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 杂志文章
doi:10.1139/y77-175
更新日期:1977-12-01 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::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::Despite major advances in conventional medical therapy, patients with heart failure continue to experience significant morbidity and mortality. Endothelin-1 (ET-1) is a potent vasocontrictor and mitogenic peptide that is activated in heart failure. There is increasing experimental and clinical evidence in support of a...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 杂志文章,评审
doi:10.1139/y03-011
更新日期:2003-06-01 00:00:00
abstract::Cardiac injury and loss of cardiomyocytes is a causative as well as a resultant condition of cardiovascular disorders, which are the leading cause of death throughout the world. This loss of cardiomyocytes cannot be completely addressed through the currently available drugs being administered, which mainly function on...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 杂志文章,评审
doi:10.1139/cjpp-2014-0468
更新日期:2015-10-01 00:00:00
abstract::Wave speed (c) must be known to separate forward- and backward-going waves during wave-intensity analysis, which measures the energy transported by the waves in the circulation. c is related to elastance; the present study was performed to measure right ventricular (RV) c during the cardiac cycle and to compare c with...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 杂志文章
doi:10.1139/y06-019
更新日期:2006-08-01 00:00:00
abstract::This study evaluated the in vitro expression of bone-related proteins by osteoblasts in the presence of different concentrations of human recombinant bone morphogenetic protein-2 (rhBMP-2). Immortalized human fetal osteoblastic cell line 1.19 (hFOB) were exposed to different concentrations of rhBMP-2 (10, 50, or 100 n...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 杂志文章
doi:10.1139/cjpp-2013-0080
更新日期:2013-11-01 00:00:00
abstract::Cerebrocrast is a novel lipophilic dihydropyridine derivative with potential neuroprotective and antidiabetic properties. We have analyzed its interaction with L-type (CaV1.2b) and T-type (CaV3.1) calcium channels using a whole-cell patch clamp in HEK 293 cells. Cerebrocrast inhibited current flux through both CaV1.2b...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 杂志文章
doi:10.1139/y09-086
更新日期:2009-11-01 00:00:00
abstract::The present research was to assess the relationship between ABCB1 (G2677T/A, C3435T) polymorphisms and lipid homeostasis as well as risk of liver injury induced by atorvastatin in in-patients from China. The lipid levels (total cholesterol, high-density lipoprotein, triglycerides) as well as metabolic enzymes of hepar...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 杂志文章
doi:10.1139/cjpp-2019-0339
更新日期:2020-01-01 00:00:00
abstract::Noradrenaline spillover from skeletal muscle vascular areas increases during exercise but the underlying mechanisms are not well understood. Muscle contraction itself causes changes in many factors that could affect noradrenaline spillover. For instance, it has been reported that bradykinin is synthesized in skeletal ...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 杂志文章
doi:
更新日期:2001-10-01 00:00:00
abstract::The purpose of this study was to investigate the cardiac adrenergic neuronal changes induced by diabetes and hypertension by using an analogue of norepinephrine, meta-iodobenzylguanidine (MIBG), and to compare these changes with the contractile state of ventricular papillary muscle. The tissue concentration of norepin...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 杂志文章
doi:10.1139/y94-164
更新日期:1994-10-01 00:00:00
abstract::Tension responses to ramp shortening of varying speed in whole muscle or single fibres from the plateau of an isometric tetanus, revealed at least two distinct phases. There was a fast initial drop in tension followed by a change of slope and a definite inflexion on the tension record. As the velocity of the imposed l...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 杂志文章
doi:10.1139/y85-268
更新日期:1985-12-01 00:00:00