Abstract:
:The lysosomal protease cathepsin D increased markedly in brown adipocytes during differentiation in primary cultures. Differentiated cells had 20 times the amount of immunoreactive cathepsin D found in preadipocytes. Cathepsin D mRNA, as estimated by relative RT-PCR, was also present in higher amounts in differentiated brown fat cells. Cathepsin D expression was not influenced by repeated exposures of brown adipocytes to norepinephrine (NE). Cathepsin D levels were also unchanged when NE was withdrawn for 48 h after cells had been exposed to NE for 7 days. In contrast, exposure of the cells to NE for 7 days increased their UCP1 content by more than twofold, which returned to basal levels within 48 h of withholding NE. The half-life of UCP1 under basal conditions and in cells chronically exposed to NE was estimated from reductions in [35S]methionine-labelled immunoprecipitable UCP1 over 72 h. UCP1 t1/2 under basal conditions was 3.7+/-0.4 days, which was similar to the half-lives of labelled mitochondrial translation products (3.6+/-0.8 days). The turnover rates of both UCP1 and mitochondrial translation products were reduced by NE. The turnover rate of UCP1 in the presence or absence of NE cannot account solely for the rapid loss of UCP1 from brown adipocytes upon withdrawal of NE. This loss was reduced when cells were incubated with inhibitors of phosphatidylinositol 3-kinases (PI 3-kinase), previously shown to block formation of autophagic vacuoles. Thus, brown adipocytes acquire a large capacity for both uncoupled metabolism and for lysosomal proteolysis during differentiation. Withdrawal of NE, as often occurs in vivo from suppression of sympathetic nervous system activity, would not only terminate thermogenesis but also favor formation of autophagic vacuoles to rapidly reduce the cell content of UCP1-containing mitochondria.
journal_name
Can J Physiol Pharmacoljournal_title
Canadian journal of physiology and pharmacologyauthors
Moazed B,Desautels Mdoi
10.1139/y02-067subject
Has Abstractpub_date
2002-06-01 00:00:00pages
515-25issue
6eissn
0008-4212issn
1205-7541journal_volume
80pub_type
杂志文章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::The hypotensive effect of clonidine in anaesthetised (pentobarbitone) cat has been analysed with the help of pharmacological tools. Application of clonidine (0.1%) to the exposed ventral surface of medulla oblongata produced hypotension (28.6%) and bradycardia (18%). Similar application of glycine (5%) and GABA (10%) ...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 杂志文章
doi:10.1139/y77-138
更新日期:1977-10-01 00:00:00
abstract::In Sprague-Dawley rats, we attempted to develop an experimental model to stimulate the cardiac sympathetic nerve. After transverse thoracotomy under anesthesia, a miniature, bipolar electrode was placed on the right ansa subclavia and it was stimulated electrically. The nerve stimulation at 2, 4, and 8.3 Hz (2 ms in d...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 杂志文章
doi:
更新日期:1997-02-01 00:00:00
abstract::The twitch-potentiating effects of opioids in the frog's skeletal muscle which are naloxone resistant and nonstereospecific were further studied. The rapid kinetics of the onset and of the offset (following washout) of the opioid effect indicates that the site for this action is the surface membrane of the muscle fibr...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 杂志文章
doi:10.1139/y86-168
更新日期:1986-07-01 00:00:00
abstract::Rats were treated daily with atropine (2.5 mg/kg), imipramine (5 mg/kg), viloxazine (5 mg/kg), or saline for 14 days. Thirty-six hours following the final injection the rats were anaesthetized with urethane and the sensitivity of neurones in the somatosensory cortex to iontophoretically applied acetylcholine (ACh) was...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 杂志文章
doi:10.1139/y80-087
更新日期:1980-05-01 00:00:00
abstract::Phosphocreatine (PCr) and intracellular pH changes were monitored by 31P-NMR spectroscopy in isolated, arterially perfused cat biceps and soleus muscles, while the pH of the CO2-bicarbonate buffered perfusate was decreased from 7.1-7.4 to 6.4-6.7 by increasing the CO2 in the equilibrating gas from 5 to up to 70%. In b...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 杂志文章
doi:10.1139/y91-047
更新日期:1991-02-01 00:00:00
abstract::The effect of chemical sympathectomy with 6-hydroxydopamine (6-OHDA) on blood volume was studied in unanesthetized splenectomized and nonsplenectomized dogs. A significant increase in total blood volume essentially accounted for by a marked plasma volume expansion was found in both groups after 6-OHDA treatment (50 mg...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 杂志文章
doi:10.1139/y77-076
更新日期:1977-06-01 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::The sarco(endo)plasmic reticulum calcium ATPase (SERCA) is responsible for transporting calcium (Ca(2+)) from the cytosol into the lumen of the sarcoplasmic reticulum (SR) following muscular contraction. The Ca(2+) sequestering activity of SERCA facilitates muscular relaxation in both cardiac and skeletal muscle. Ther...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 杂志文章,评审
doi:10.1139/cjpp-2014-0463
更新日期:2015-10-01 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::Although there are many studies reporting correlations between relative body weight and blood pressure, the correlations are generally of low order. Furthermore, these observational studies provide, at best, circumstantial evidence concerning the effect of weight reduction on elevated blood pressure. After outlining k...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 临床试验,杂志文章
doi:10.1139/y86-142
更新日期:1986-06-01 00:00:00
abstract::The aim of this study was to clarify if small doses of neurotensin (2.5 and 5.0 pmol.kg-1.min-1, i.v.) in dogs alter the postprandial motor pattern of the duodenum in comparison with the adjacent jejunum. The intestinal motor patterns were quantified by means of closely spaced strain gauge transducers and a computeriz...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 杂志文章
doi:10.1139/y89-247
更新日期:1989-12-01 00:00:00
abstract::Our studies are guided by the novel hypothesis that protein tyrosine phosphorylation is an important mechanism for regulating contraction of smooth muscle. Several lines of evidence are reviewed which suggest that enhanced tyrosine phosphorylation participates in mechanisms that regulate cytosolic Ca2+ and Ca2+ sensit...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 杂志文章,评审
doi:10.1139/y94-207
更新日期:1994-11-01 00:00:00
abstract::N,N-Diethyl-2-(1-pyridyl)ethylamine (E-2-P) produced 59 +/- 7% of the maximal response to histamine in guinea pig ileal longitudinal smooth muscle and antagonized the responses of this tissue to histamine. The estimated binding constant of E-2-P for the histamine receptor predicted a binding curve nearly coincident wi...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 杂志文章
doi:10.1139/y80-198
更新日期:1980-11-01 00:00:00
abstract::Over the past few years, a number of cases of tendon injuries associated with statin therapy have been reported. In this study, we assessed whether statins can affect the extracellular matrix (ECM) of the deep digital flexor tendon (DDFT) and patellar tendon (PT). Wistar rats were assigned to groups treated with atorv...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 杂志文章
doi:10.1139/cjpp-2016-0133
更新日期:2017-04-01 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::Angiotensin II (ANG II) and vasopressin (AVP) are two powerful vasoconstrictors, and atrial natriuretic peptide (ANP) is a potent vasorelaxant. The changes in the density or affinity of binding sites for these agents that may alter target organ responsiveness in hypertension are reviewed. ANG II binding in mesenteric ...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 杂志文章,评审
doi:10.1139/y89-178
更新日期:1989-09-01 00:00:00
abstract::Guanine nucleotide binding proteins (G proteins) are largely grouped into three classes: heterotrimeric G proteins, ras-like or small molecular weight GTP binding proteins, and others like Gh. In the heart G proteins transduce signals from a variety of membrane receptors to generate diverse effects on contractility, h...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 杂志文章,评审
doi:
更新日期:2000-03-01 00:00:00
abstract::Both physical activity and exposure to environmental stressors such as cold, heat, and high altitudes modify various components of immune function: T cell counts, natural killer (NK) cell counts, and cytolytic activity, cytokine secretion, lymphocyte proliferation and immunoglobulin levels. Light physical activity or ...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 杂志文章,评审
doi:10.1139/cjpp-76-5-539
更新日期:1998-05-01 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::Spironolactone at 10 mg per kilogram per day was given to control and 'one-kidney-one-clip' hypertensive dogs for 6--7 weeks. Compared with untreated animals the treated animals had a lower arterial water content, a higher arterial, myocardial, and skeletal muscle sodium content, and variable changes in tissue potassi...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 杂志文章
doi:10.1139/y79-096
更新日期:1979-06-01 00:00:00
abstract::The blood volume of anesthetized rats was expanded acutely by 33% with donor blood while a caval snare was gradually tightened so that right atrial pressure (RAP) was prevented from rising (n = 6). In control experiments (n = 5) an aortic snare was used to hold mean arterial blood pressure near the values found in the...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 杂志文章
doi:10.1139/y84-131
更新日期:1984-07-01 00:00:00
abstract::Structural analysis of G-protein-coupled receptors has largely been limited to photoaffinity labeling and site-directed mutagenesis. This is primarily due to the difficulty in the production of antibodies against this class of receptors. We were therefore interested in tagging the amino-terminal side of the human angi...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 杂志文章
doi:
更新日期:1997-06-01 00:00:00
abstract::The endothelin receptors in rabbit isolated rings of saphenous artery and saphenous vein have been characterized using endothelin-1, endothelin-2, endothelin-3, sarafotoxin S6c, and BQ123. Although artery rings were more sensitive than those from vein to the contractile action of phenylephrine, endothelin-1 was about ...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 杂志文章
doi:10.1139/y93-122
更新日期:1993-10-01 00:00:00
abstract::A systematic study has been performed in various segments of the intestine and in the urinary bladder of the mouse to identify tissues that respond to kinins and possess B1 and (or) B2 receptors. The stomach was found to contain B1 and B2 functional sites that show pharmacological profiles compatible with B1 and B2 re...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 杂志文章
doi:10.1139/y95-240
更新日期:1995-12-01 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 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::Luminal nutrition is important for the maintenance of small intestinal structure and function. The equilibrium between crypt cell production and villous cell loss in the mucosal epithelium of the small intestine is altered under certain conditions such as after a small bowel resection. Immediately after resection, the...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 杂志文章,评审
doi:10.1139/y90-095
更新日期:1990-05-01 00:00:00
abstract::Hyperglycemia in diabetes induces increased endothelin-1 (ET-1) production in the retina, kidney, and heart that may lead to hemodynamic impairment, permeability alteration, and increased extracellular matrix (ECM) protein production. Chronically elevated blood glucose levels may cause oxidative stress in these target...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 杂志文章
doi:10.1139/Y08-033
更新日期:2008-06-01 00:00:00
abstract::Premature weaning of rats to high carbohydrate diets causes a variety of short- and long-term changes in lipid metabolism, but the mechanisms involved are unclear. It is likely that interaction of diet with certain emerging hormonal control patterns during weaning might condition metabolic control and (or) subsequent ...
journal_title:Canadian journal of physiology and pharmacology
pub_type: 杂志文章,评审
doi:10.1139/y85-093
更新日期:1985-05-01 00:00:00