Abstract：
:Androgens have been reported to stimulate progesterone production by granulosa cells of several species, and to act synergistically with FSH in stimulation of progesterone accumulation by rat granulosa cells. Studies were undertaken to examine the effect of androgens on FSH-stimulated progesterone production in culture by granulosa cells derived from prepubertal pig ovaries. When included in 24-h culture with FSH, both androstenedione and testosterone caused a reduction in progesterone accumulation, but dihydrotestosterone and androsterone did not. Granulosa cells were cultured for 24 h with FSH and [14C]progesterone with or without testosterone; testosterone did not affect the rate of overall metabolism of [14C]progesterone and it was therefore concluded that testosterone inhibited progesterone synthesis, rather than enhancing its catabolism. 17 beta-Estradiol also inhibited FSH-stimulated progesterone accumulation. To determine whether the action of testosterone was mediated by conversion to estradiol, granulosa cells were cultured with FSH and testosterone with or without an aromatase inhibitor (4-acetoxy-androstenedione). The aromatase inhibitor failed to prevent the testosterone-induced reduction in progesterone accumulation, although it markedly inhibited estradiol accumulation. These results indicate that theca-derived androgens can inhibit FSH-stimulated progesterone production by granulosa cells in the prepubertal pig, independently of estradiol.
journal_name
Can J Physiol Pharmacoljournal_title
Canadian journal of physiology and pharmacologyauthors
Evans G,Lischinsky A,Daniel SA,Armstrong DTdoi
10.1139/y84-138subject
Has Abstractpub_date
1984-07-01 00:00:00pages
840-5issue
7eissn
0008-4212issn
1205-7541journal_volume
62pub_type
杂志文章abstract：:Although mitochondrial transcription factor A (TFAM) is a protective component of mitochondrial DNA and a regulator of calcium and reactive oxygen species (ROS) production, the mechanism remains unclear. In heart failure, TFAM is significantly decreased and cardiomyocyte instability ensues. TFAM inhibits nuclear facto...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/cjpp-2016-0718
更新日期：2018-02-01 00:00:00
abstract：:Energy-deprivation contractures were investigated in unloaded rat ventricular myocytes. Application of 2 mM cyanide in the presence of 10 mM 2-deoxyglucose (metabolic blockade) led to a rapid shortening "contracture" (maximum speed 1.5 +/- 0.2% control cell length/s). Cells shortened to a constant length of 69 +/- 1.6...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y90-029
更新日期：1990-02-01 00:00:00
abstract：:We investigated potential sex differences in bone resorption and the conservation of whole body bone mass in 24-week-old Sprague-Dawley rats maintained on a 1.0% calcium diet and then fed diets containing 0.02, 0.5, 1.0, or 1.75% calcium for 31 days. Lowering dietary calcium from 1.00% to 0.02% doubled whole skeleton ...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：
更新日期：2001-05-01 00:00:00
abstract：:Angiotensin exerts numerous contractile and secretory effects by activating specific receptors. Recent pharmacological findings obtained with this peptide in various laboratories are analyzed, using the order of potency of agonists and the affinity of competitive antagonists as criteria for the classification of recep...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章,评审
doi：10.1139/y79-020
更新日期：1979-02-01 00:00:00
abstract：:The synthesis, receptor binding, and agonist activity of a series of truncated atrial natriuretic analogs (ANF) are described. These analogs incorporate two portions of the native 28 amino peptide, the eight amino acids C-terminal to Cys7, and two amino acids from the C-terminus (phenylalanine and arginine), into disu...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y91-240
更新日期：1991-10-01 00:00:00
abstract：:Beneficial effects of an antioxidant (N-acetyl-L-cysteine, NAC) and an angiotensin I-converting enzyme (ACE) inhibitor (ramipril) were assessed in a rat model of insulin resistance induced by 10% glucose feeding for 20 weeks. Treatments with NAC (2 g/kg per day) and ramipril (1 mg/kg per day) were initiated at 16 week...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/Y08-090
更新日期：2008-11-01 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：:Some current questions regarding muscle afferent receptors are discussed. These include the significance of variable distribution patterns of muscle spindles in different muscles and of differences in intrinsic spindle morphology. The significance of the very large and variable population of small myelinated afferent ...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y81-100
更新日期：1981-07-01 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：:Several experimental data document an activation of the mitogen-activated protein kinases Erk1 and Erk2 by bradykinin (BK), an agonist of the kinin B2 receptor (B2R). In contrast, other reports showed an inhibitory modulation of mitogenesis by BK. Therefore, we explored in the isolated glomeruli the effect of B2R acti...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y02-033
更新日期：2002-04-01 00:00:00
abstract：:The isometric contractile properties of frog (Rana pipiens) and toad (Bufo bufo) sartorii have been studied over the temperature range from 0 to 20 degrees C. The isometric twitch tension was found to vary considerably between these two species and between muscles in the same species. Between 0 and 4 degrees C there w...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y81-082
更新日期：1981-06-01 00:00:00
abstract：:In vitro coronary artery responsiveness to angiotensin I, angiotensin II, noradrenaline, phenylephrine, BHT 920, and potassium chloride together with functional relaxation to acetylcholine was investigated in dogs with pacing-induced heart failure treated with enalapril (oral administration of 10 mg.day-1) for a mean ...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y92-199
更新日期：1992-10-01 00:00:00
abstract：:Space travelers experience anorexia and body weight loss in a microgravity environment, and microgravity-like situations cause changes in hypothalamic activity. Hypothalamic melanocortins play a critical role in the regulation of metabolism. Therefore, we hypothesized that microgravity affects metabolism through alter...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/Y09-074
更新日期：2009-10-01 00:00:00
abstract：:Several lines of evidence suggest that the responsiveness of the airways is heterogeneous, although the magnitude of this heterogeneity has not been quantified. We have developed a videomicroscopic method that allows the measurements of the responsiveness of individual explanted airways to contractile agonists such as...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：
更新日期：1997-07-01 00:00:00
abstract：:The effects of beta-adrenergic blocking agents, timolol and atenolol (1-1000 microM), were studied on rat heart sarcolemmal ATPase and Ca2+ binding activities. Timolol, unlike atenolol, increased both Ca2+-stimulated ATPase and ATP-dependent Ca2+ binding; the maximal effects were seen at 1 microM concentration of timo...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y83-037
更新日期：1983-03-01 00:00:00
abstract：:Dilated cardiomyopathy (DCM) is a multifactorial disease characterized by left ventricular dilation that is associated with systolic dysfunction and increased action potential duration. The Kir2.x K⁺ channels (encoded by KCNJ genes) regulate the inward rectifier current (IK1) contributing to the final repolarization i...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/cjpp-2012-0413
更新日期：2013-08-01 00:00:00
abstract：:Barbital-sedated, warm-acclimated (WA) or cold-acclimated (CA) rats were infused intravenously with noradrenaline (NA) at doses that elicited graded calorigenic responses. Blood flow (Q) to the various bodies of brown adipose tissue (BAT), the major sites of the NA-induced calorigenesis, was measured with labeled micr...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y80-140
更新日期：1980-08-01 00:00:00
abstract：:This study investigated the gastroprotective effects of N-acetylcysteine (NAC) against indomethacin-induced gastric ulcer in rats. Ulceration was induced by a single oral administration of indomethacin (30 mg/kg). 50 male albino rats were allocated into 5 equal groups: control group received normal saline orally, indo...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/cjpp-2016-0442
更新日期：2017-04-01 00:00:00
abstract：:Single-electrode voltage-clamp experiments were made on CA1 neurons in the presence of tetrodotoxin and K channel blockers. Applications of halothane (1-3% v/v) for 3-10 min caused a similar marked and reversible depression of slow inward currents (probably Ca currents) evoked by depolarizing pulses from a holding pot...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y88-257
更新日期：1988-12-01 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：:The ability of human skeletal muscle to provide anaerobically derived ATP during short-term, intense activity is examined. The paper emphasizes the information obtained from direct measurements of substrates, intermediates, and products of the pathways in muscle that provide anaerobically derived ATP. The capacity of ...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章,评审
doi：10.1139/y92-023
更新日期：1992-01-01 00:00:00
abstract：:Barbiturate actions on excitatory synaptic responses in CA 1 and dentate regions of hippocampal slices were studied to determine whether different effects occur on anatomically distinct synaptic pathways. Pentobarbital facilitated transmission between stratum radiatum inputs and CA 1 neurons at low concentrations (0.0...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y87-065
更新日期：1987-03-01 00:00:00
abstract：:The aim of the present study was to characterize the effects of pituitary adenylate cyclase activating polypeptide (PACAP) on the endocrine pancreas in anesthetized dogs. PACAP(1-27) and a PACAP receptor (PAC(1)) blocker, PACAP(6-27), were locally administered to the pancreas. PACAP(1-27) (0.005-5 microg) increased ba...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y03-067
更新日期：2003-07-01 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：:Double-barrelled ion-sensitive microelectrodes were used to measure changes in the intracellular activities of K+, Na+, and Cl- (aKi, aNai, aCli) in neurones of rat sympathetic ganglia and in glial cells of slices from guinea-pig olfactory cortex. In sympathetic neurones, carbachol and gamma-aminobutyric acid (GABA) p...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y87-164
更新日期：1987-05-01 00:00:00
abstract：:Glucose utilization and insulin and growth hormone responses were evaluated in eight obese women by three rapid intravenous glucose tolerance tests (IVGTT): during a control period, and after 1 and 3 weeks of a 750 kcal/day protein-lipid diet (1 kcal = 4.1855 kJ). Weight loss averaged 454 g/day during the 1st week and...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y82-044
更新日期：1982-03-01 00:00:00
abstract：:Lesion to the posterior parietal cortex in monkeys and humans produces spatial deficits in movement and perception. In recording experiments from area 7a, a cortical subdivision in the posterior parietal cortex in monkeys, we have found neurons whose responses are a function of both the retinal location of visual stim...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y88-078
更新日期：1988-04-01 00:00:00
abstract：:The role of sodium and calcium on strophanthidin inotropy was studied in canine cardiac Purkinje fibers perfused in vitro under conditions that vary cellular sodium and calcium. With high concentrations of strophanthidin (greater than or equal to 10(-7) M), force increases more in the presence of low [Ca]0 or high [Na...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y86-235
更新日期：1986-11-01 00:00:00
abstract：:The effect of intracerebroventricular (i.c.v.) injection of the alpha 2-adrenoceptor agonists clonidine and B-HT 920 on mean arterial pressure (MAP), heart rate (HR), and plasma concentrations of noradrenaline and adrenaline was examined in conscious unrestrained rats. The injection of 1.0 microgram clonidine signific...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y88-237
更新日期：1988-11-01 00:00:00
abstract：:The role of iron-loaded transferrin in xanthine-xanthine oxidase (X-XO) induced cardiac injury in isolated perfused rat hearts was examined. X (2 mM) - XO (10 U/L) perfusion resulted in contractile failure, a rise in resting tension, an increase in lipid peroxidation, and myocardial cell damage. The addition of transf...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y90-068
更新日期：1990-04-01 00:00:00
