Abstract：
:Experiments in right atria isolated from adult male rats were designed to determine which of the alpha 1-adrenergic receptor (alpha 1-AR) subtypes are involved in the positive chronotropic effect of phenylephrine, an alpha 1-AR agonist. Chloroethylclonidine (CEC), an irreversible alpha 1b-, alpha 1c-, and alpha 1d-AR antagonist, did not alter the efficacy or potency of phenylephrine; however, CEC did elicit a concentration-dependent negative chronotropic effect and reduce the absolute maximum spontaneous rate observed in the presence of phenylephrine. WB4101, a competitive alpha 1a- and alpha 1c-AR-selective antagonist, did not alter basal spontaneous rate or the efficacy of phenylephrine, but it did produce a significant rightward shift of the phenylephrine concentration-response curve. Phenoxybenzamine, an irreversible nonselective alpha-AR antagonist, elicited a concentration-dependent negative chronotropic effect, a significant rightward shift of the phenylephrine concentration-response curve, and a reduction in the efficacy of phenylephrine. The chronotropic action of the beta-adrenergic agonist isoproterenol was not affected by CEC, WB4101, or phenoxybenzamine. These data suggest that the positive chronotropic effect of alpha 1-adrenergic agonists in rat right atria is mediated via stimulation of alpha 1a-ARs.
journal_name
Can J Physiol Pharmacoljournal_title
Canadian journal of physiology and pharmacologyauthors
Williamson AP,Seifen E,Lindemann JP,Kennedy RHdoi
10.1139/y94-226subject
Has Abstractpub_date
1994-12-01 00:00:00pages
1574-9issue
12eissn
0008-4212issn
1205-7541journal_volume
72pub_type
杂志文章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：:Isolated rabbit hearts undergo ventricular depolarization when exposed to 0.5 mM K--Krebs during 30 to 45 min. A ventricular tachyarrhythmia develops when these hearts are allowed to repolarize in 1.5 mM K--Krebs. Ventricular fibrillation usually follows. These arrhythmias do not cease spontaneously. Initially, perfus...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y82-226
更新日期：1982-12-01 00:00:00
abstract：:The pHi regulation from intracellular acidosis in the central nervous system appears to be mediated by mechanisms driven by the large inwardly directed Na+ gradient. The involvement of these mechanisms in pHi regulation of neurones and glial cells has been investigated in the leech central nervous system using ion-sel...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y92-273
更新日期：1992-01-01 00:00:00
abstract：:The placental transfer of indomethacin was studied in the rabbit at 30 days of gestation and in the sheep between 120 and 135 days of gestation. Plasma concentrations of indomethacin reached a maximum of 13.7 +/- 1.6 and 10.9 +/- 1.5 microgram/mL in the doe and fetuses, respectively, at 1 h following a maternal subcut...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y81-053
更新日期：1981-04-01 00:00:00
abstract：:A variety of neural factors can influence reproductive hormone secretion by neuromodulatory actions within the hypothalamus or neuroendocrine actions within the anterior pituitary gland. Passive immunoneutralization and antagonist administration protocols have suggested physiological roles for a number of these factor...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y92-102
更新日期：1992-05-01 00:00:00
abstract：:The main factors of myocardial ischemia are hypoxia, substrate deprivation, acidosis, and high extracellular potassium concentration ([K+]e), but the influence of each of these factors has not yet been evaluated in a cardiomyocyte (CM) culture system. Electromechanical responses to the individual and combined componen...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y02-143
更新日期：2002-12-01 00:00:00
abstract：:Norethandrolone (NE) and other androgenic steroids have been shown to be renotropic in various species and have also been reported to have salutary effects in patients with diminished renal function. Renal cortical slices prepared from rats pretreated with NE showed an increased capability to concentrate p-aminohippur...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y75-104
更新日期：1975-10-01 00:00:00
abstract：:In the present study we have compared the effect of intravenous infusion of a calcium channel blocker, nifedipine (1.0 micrograms.kg-1.min-1 for 20 min), with that of isoproterenol (0.1 micrograms.kg-1.min-1 for 20 min) on the hemodynamic parameters and the vascular response of different locations and tissue layers of...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y90-238
更新日期：1990-12-01 00:00:00
abstract：:Physical and lifestyle data were collected from 62 postmenopausal women who had declined hormone replacement therapy. Potential predictor variables were examined for their associations with bone mineral density (BMD) of the lumbar spine and femoral neck as assessed by dual x-ray absorptiometry. Body weight demonstrate...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：
更新日期：1996-08-01 00:00:00
abstract：:Ethanol was administered to rats by oral intubation 3 h after intraperitoneal administration of calcium carbimide. Increased blood acetaldehyde concentration and the presence of acetaldehyde in brain were found for the calcium carbimide--ethanol interaction. There was no detectable brain acetaldehyde for ethanol admin...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y81-011
更新日期：1981-01-01 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：:Nitric oxide (NO) production occurs through oxidation of the amino acid L-arginine by NO synthase (NOS). NO inhibits platelet activation by increasing the levels of cyclic guanosine monophosphate (cGMP), thus maintaining vascular homeostasis. Our group previously demonstrated (da Silva et al. 2005) an enhancement of t...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y10-111
更新日期：2011-02-01 00:00:00
abstract：:The development of cardiac hypertrophy was examined in rats given ethanol in a nutritionally adequate, liquid diet mixture, by intubation, in severely intoxicating doses at 8-h intervals for up to 96 h, alone or in combination with prazosin. Other groups of rats received isocalorically paired quantities of maltose-dex...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y89-040
更新日期：1989-03-01 00:00:00
abstract：:Angiotensin II (AngII) plays an important role in the regulation of vascular smooth muscle function. However, little is known about AngII and its receptors AT1 (AT1R) and AT2 (AT2R) and their modulation of intracellular calcium in vascular endothelial cells (VECs) in general and more particularly of human origin. Usin...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/cjpp-2017-0416
更新日期：2017-10-01 00:00:00
abstract：:Atrial natriuretic peptide (ANP) and B-type natriuretic peptide (BNP) are cardiac hormones synthesized in and secreted from the heart. ANP and BNP bind the common receptor guanylyl cyclase-A (GC-A) and possess biological actions. Based on their diuretic, natriuretic, and vasodilating activities, they are now widely us...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章,评审
doi：10.1139/y11-022
更新日期：2011-08-01 00:00:00
abstract：:The effect of neural inhibition on the electrical activities of circular and longitudinal colonic smooth muscle was investigated. In addition, a comparative study was carried out between circular muscle preparations with and without the "submucosal" and "myenteric plexus" network of interstitial cells of Cajal (ICC) t...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y90-063
更新日期：1990-03-01 00:00:00
abstract：:The effect of hemorrhagic shock, hypoxemia, and anoxia on the levels of adenine and pyridine nucleotides of liver and kidney was assessed. ATP levels in liver and kidney of animals in shock or animals subjected to 7 min of anoxia decreased by 85 and 73%, respectively. Under hypoxic conditions (arterial PO2 AT 18 MMHg)...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y76-104
更新日期：1976-10-01 00:00:00
abstract：:Vascular smooth muscle tone is regulated primarily by the sarcoplasmic free Ca2+ concentration, which determines the level of myosin phosphorylation. Stimulation of the muscle results in an increase in free [Ca2+], whereupon Ca2+ binds to calmodulin, inducing a conformational change enabling calmodulin to interact wit...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章,评审
doi：10.1139/y94-130
更新日期：1994-08-01 00:00:00
abstract：:The purpose of this study was to characterize the biological activity of the synthetic rat growth hormone releasing factor analogue rGRF(1-29)NH2 and to compare its action on growth hormone (GH) release to that of authentic rGRF(1-43)OH. We first compared the concentration-response characteristics of the two peptides ...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y91-026
更新日期：1991-02-01 00:00:00
abstract：:Liver diseases are associated with a decrease in hepatic drug elimination, but there is evidence that cirrhosis does not result in uniform changes of cytochrome P450 (CYP) isoenzymes. The objective of this study was to determine the content and activity of four CYP isoenzymes in the bile duct ligation and carbon tetra...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：
更新日期：2000-11-01 00:00:00
abstract：:Significant tension development resulting from the administration of lanthanum salts (La3+) to isolated aorta tissues was observed in preparations from the spontaneously hypertensive rat (SHR) but not in preparation from age-matched normotensive Wistar rats (NWR). The response to La3+ was significantly greater in tiss...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y77-148
更新日期：1977-10-01 00:00:00
abstract：:Intrinsic regulation of hepatic blood flow is mediated only through the hepatic artery because the liver is not able to directly regulate portal vein blood flow. Hepatic metabolic activity does not affect hepatic artery flow. Although the hepatic artery is affected by sympathetic nerves and blood-borne agents, the int...
journal_title：Canadian journal of physiology and pharmacology
pub_type：
doi：
更新日期：1996-03-01 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：:Idiopathic pulmonary arterial hypertension (IPAH) is a rare and devastating condition. There is no known cure for IPAH, and current treatment options are not always effective. Autologous myeloid angiogenic cells (MACs) have been explored as a novel therapy for IPAH, but preliminary data from clinical trials show limit...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/cjpp-2018-0424
更新日期：2019-04-01 00:00:00
abstract：:Nonalcoholic fatty liver disease (NAFLD) is a spectrum of chronic liver conditions that are characterized by steatosis, inflammation, fibrosis, and liver injury. The global prevalence of NAFLD is rapidly increasing in proportion to the rising incidence of obesity and type 2 diabetes. Because NAFLD is a multifaceted di...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章,评审
doi：10.1139/cjpp-2016-0681
更新日期：2017-10-01 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：:The influences of hypertension and hypothyroidism on diabetic cardiomyopathy are not clear. We studied this problem further by characterizing the effects of chronic triiodothyronine (T3) treatment on cardiac performance of diabetic renovascular hypertensive (RVH) rats. Hypertension was effected by clipping the left re...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y91-053
更新日期：1991-03-01 00:00:00
abstract：:Vanadium (V) as sodium orthovanadate induces an increase in lipid peroxidation in the kidneys after a single subcutaneous or intraperitoneal injection to rats or mice. The rate of malondialdehyde (MDA) formation, an index of lipid peroxidation, by kidney homogenates increased by more than 100% 1 h after injection. Chr...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y85-037
更新日期：1985-03-01 00:00:00
abstract：:The enhancement of the response of an isolated strip of lactating mouse mammary gland to oxytocin, resulting from dilution of the Tyrode solution in which oxytocin is administered, is due to the effects of hypotonicity per se and not to changes in concentration of any of the ions in the bathing solution. Inhibition of...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y79-047
更新日期：1979-03-01 00:00:00
abstract：:In vivo fatty acid synthesis and the pathways of glycerol-3-phosphate (G3P) production were investigated in brown adipose tissue (BAT) from rats fed a cafeteria diet for 3 weeks. In spite of BAT activation, the diet promoted an increase in the carcass fatty acid content. Plasma insulin levels were markedly increased i...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y08-052
更新日期：2008-07-01 00:00:00
