Abstract：
:We examined whether there was a threshold for change in fetal arterial PO2 to elicit alterations in plasma adrenocorticotropic hormone, arginine vasopressin, or cortisol, or to affect the incidence of fetal breathing movements or eye movements and we determined whether such a threshold changed with gestational age. Fetal sheep were exposed to two levels of hypoxemia, mild (4.6-5.3 mmHg PO2 drop) and moderate (8.3-8.8 mmHg PO2 drop) (1 mmHg = 133.322 Pa) for 1 h without pH change at 125-129 or 134-147 days of gestation within 7 days of spontaneous labor. Hypoxemia was induced by altering the inspired percent oxygen of the mother. No significant hormonal and biophysical changes were observed in mild hypoxemia at either age. In moderate hypoxemia at 125-129 days of gestation, there were significant increases of fetal adrenocorticotropic hormone, arginine vasopressin, and cortisol concentrations, and a decreased incidence of fetal breathing movements and eye movements. At 134-147 days of pregnancy, moderate hypoxemia induced a significant increase in adrenocorticotropic hormone, but the response was less than at 125-129 days of gestation. The arginine vasopressin response was similar to that at 125-129 days and there was no significant change in cortisol. There was a significant decrease in fetal breathing movements but not in eye movements. We conclude that a threshold of fetal arterial PO2 drop exists between 5 and 8 mmHg to elicit endocrine or biophysical responses to hypoxemia in fetal sheep at 125-129 days of gestation.(ABSTRACT TRUNCATED AT 250 WORDS)
journal_name
Can J Physiol Pharmacoljournal_title
Canadian journal of physiology and pharmacologyauthors
Akagi K,Challis JRdoi
10.1139/y90-080subject
Has Abstractpub_date
1990-05-01 00:00:00pages
549-55issue
5eissn
0008-4212issn
1205-7541journal_volume
68pub_type
杂志文章abstract：:Acute administration of morphine sulfate at 20 mg/kg decreased mouse cerebellar adenosine 3',5'-cyclic phosphate (cAMP) levels while not affecting cAMP phosphodiesterase (EC 3.1.4.17). The cAMP levels and cAMP phosphodiesterase activies were not affected by chronic treatment. However, cAMP levels increased during abru...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y77-017
更新日期：1977-02-01 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：: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：:The kinetics of sodium gradient dependent phosphate uptake by the renal brush border membrane vesicles of the rat have ben studied under various conditions of temperature and pH. From 7 to 30 degrees C the Lineweaver-Burk plots are linear, and the apparent Km progressively increases from 54 to 91 microM. Above 30 degr...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y84-034
更新日期：1984-02-01 00:00:00
abstract：:In vivo assessment of treatment efficacy on postinfarct left ventricular (LV) remodeling is crucial for experimental studies. We examined the technical feasibility of serial magnetic resonance imaging (MRI) for monitoring early postinfarct remodeling in rats. MRI studies were performed with a 7-Tesla unit, 1, 3, 8, 15...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y05-115
更新日期：2005-12-01 00:00:00
abstract：:Single ventricular cells have been isolated from adult guinea pig heart using a collagenase enzyme method. The procedure is straightforward, takes about 20 min, and yields 40-65% rod-shaped cells which are quiescent in millimolar Ca2+ solution. Electrophysiological studies involving external ion changes and ionic chan...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y81-139
更新日期：1981-08-01 00:00:00
abstract：:The rate of appearance of unlabelled glucose was calculated from changes in plasma glucose specific radioactivity after a single intravenous injection of labelled glucose and compared with the actual constant infusion rate of unlabelled glucose into an anaesthetized dog with all sources of endogenous glucose productio...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y79-191
更新日期：1979-11-01 00:00:00
abstract：:The secretion of cyclic AMP, cyclic GMP, protein, calcium, and bicarbonate in the pancreatic juice of three nonanesthetized dogs with chronic gastric and duodenal Thomas cannulae has been studied. Intravenous infusions of increasing doses of cholecystokinin-pancreozymin (CCK) (1.5, 3, 6, 12, 24 Crick Harper-Raper (CHR...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y79-082
更新日期：1979-06-01 00:00:00
abstract：:In addition to bronchial smooth muscle, histamine and other mediators act in bronchial asthma on the microcirculation of pulmonary connective tissue. The mediators induce enhanced blood flow, and by acting on the blood-tissue barrier, they induce increase in vasopermeability with edema and in more severe injury microh...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章,评审
doi：10.1139/y87-077
更新日期：1987-03-01 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：:The mechanisms responsible for microbially induced epithelial apoptosis and increased intestinal permeability remain unclear. This study assessed whether purified bacterial lipopolysaccharide (LPS) increases epithelial apoptosis and permeability and whether these changes are dependent on caspase-3 activation. In nontu...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y06-056
更新日期：2006-10-01 00:00:00
abstract：:To elucidate the involvement of the brain renin-angiotensin system and the brain atrial natriuretic polypeptide (ANP) system in the regulation of ANP secretion from the heart, the effects of intracerebroventricular administration of angiotensin II and ANP on the plasma ANP level were examined in conscious unrestrained...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y88-044
更新日期：1988-03-01 00:00:00
abstract：:In open-chest pentothal-chloralose anesthetized dogs, plasma catecholamine and cyclic AMP levels were evaluated in the aortic and coronary sinus blood, during stimulations of the left ansa subclavia (1, 2, and 4 Hz). Basal aortic and coronary sinus catecholamine levels were respectively 0.373 +/- 0.090 and 0.259 +/- 0...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y81-080
更新日期：1981-06-01 00:00:00
abstract：:Coronary flow was recorded from spontaneously beating isolated perfused hearts of rats and guinea pigs. Arachidonic acid (AA), in single bolus doses, produced a fast short lasting coronary constriction followed by a slow developing but persisting vasodilation. These reactions (biphasic type) were characteristic of the...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y84-211
更新日期：1984-10-01 00:00:00
abstract：:The mammalian daily (circadian) clock is located in the suprachiasmatic nuclei of the hypothalamus. Clock function can be detected by the measurement of the circadian change in spontaneous firing rate of suprachiasmatic nuclei cells in a brain slice preparation in vitro. We investigated the effects of neuropeptide Y o...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：
更新日期：2000-02-01 00:00:00
abstract：:In using pharmacologic stimuli, force-velocity (FV) curves are usually obtained by the method of quick release (QR) and redevelopment of shortening at peak tetanic tension; the advantage of the method being that the active state is at maximum. However, the QR may itself reduce the intensity of the active state and res...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y85-008
更新日期：1985-01-01 00:00:00
abstract：:To investigate the capacity of efferent sympathetic neurons to modulate the failing heart, stellate ganglion stimulation was performed in dogs with biventricular heart failure induced by rapid ventricular pacing (240 beats/min) for 4-6 weeks. Less noradrenaline was released from cardiac myoneural junctions into corona...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：
更新日期：1996-09-01 00:00:00
abstract：:Remote ischemia-reperfusion detrimentally affects myocardial function by initially interfering with the rate of contraction. We investigated the usefulness of isoproterenol versus external electrical pacing in attenuating secondary functional damage of isolated Wistar rat atria. Atrial strips (n = 10/group) were bathe...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y03-125
更新日期：2004-01-01 00:00:00
abstract：:Opioid and N-methyl-d-aspartate (NMDA) receptors mediate different effects of fluoxetine. We investigated whether opioid and NMDA receptors are involved in the protective effect of fluoxetine against the behavioral despair induced by acute physical stress in male mice. We used the forced swimming test (FST), tail susp...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/cjpp-2015-0429
更新日期：2016-06-01 00:00:00
abstract：:Continuous exposure to nitroglycerin (GTN) results in development of tolerance and is associated with increased free radical production and abnormal endothelial function. Elevated plasma biomarkers of inflammation have been shown to be associated with endothelial dysfunction in most cardiovascular conditions. It remai...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章,随机对照试验
doi：10.1139/y09-030
更新日期：2009-06-01 00:00:00
abstract：:The effects of modafinil on heat thermoregulatory responses were studied in 10 male subjects submitted to a sweating test after taking 200 mg of modafinil or placebo. Sweating tests were performed in a hot climatic chamber (45 degrees C, relative humidity <15%, wind speed = 0.8 m x s(-1), duration 1.5 h). Body tempera...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 临床试验,杂志文章
doi：10.1139/y02-092
更新日期：2002-08-01 00:00:00
abstract：:The mesenteric vascular bed preparation of control and pinealectomized (PX) male Wistar rats was used to examine vascular reactivity to two concentrations each of norepinephrine, serotonin, angiotensin, and potassium. Vasoconstrictor responses to 50- and 100-ng injections of norepinephrine and 0.5- and 1.0-microgram i...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y80-049
更新日期：1980-03-01 00:00:00
abstract：:Longitudinal muscle of myometrial tissues from immature rats were examined by quantitative thin section electron microscopy for the presence of gap junctions after treatment with estradiol with and without tamoxifen, and cycloheximide for 1-6 days. Gap junctions were present between myometrial cells on days 4, 5, and ...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y86-117
更新日期：1986-06-01 00:00:00
abstract：:Sarcoplasmic reticulum (SR) calcium handling in diaphragm was compared between mdx mice (7-8 weeks old) and age-matched controls. The total SR Ca2+ load was released from the SR by rapidly cooling muscle bundles from 22 to -1 degree C. The plateau amplitude of the rapid cooling contracture (RCC) was considered as an i...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/cjpp-76-12-1161
更新日期：1998-12-01 00:00:00
abstract：:Anti-mitogenic agents currently used to prevent restenosis in drug-eluting stents delay re-endothelialization. Delayed re-endothelialization is now considered as the main cause of late stent thrombosis with drug-eluting stents, which emphasizes the need for new treatments. We have shown that systemic insulin treatment...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/cjpp-2013-0038
更新日期：2013-12-01 00:00:00
abstract：:Eight pure triterpenoid saponin compounds isolated from the root of Polygala senega L., a plant indigenous to the Canadian prairies, were evaluated for their immunological activity in mouse models. The specific antibody responses of the IgG2a subclass increased significantly when isolated P. senega saponins were used ...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/Y07-109
更新日期：2007-11-01 00:00:00
abstract：:We tested the effects of inhibiting the carbonic anhydrase activity of rat soleus and extensor digitorum longus muscles on the isometric contractile properties and the resistance to fatigue. SOL and EDL muscles from female rats were incubated in vitro in the presence of methazolamide, a specific inhibitor of carbonic ...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y89-103
更新日期：1989-06-01 00:00:00
abstract：:The goal of the present study was to investigate the formation of portacaval shunts in a new experimental model of chronic portal hypertension, portal vein stenosis in the cat. The procedure gradually occluded the portal vein by use of an Ameroid constrictor around the portal vein. After 4 weeks, the portal vein was c...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y93-098
更新日期：1993-09-01 00:00:00
abstract：:The rat atrium contains a potent natriuretic factor which appears to inhibit the sodium reabsorption in the collecting tubules of the kidneys. We examined the effects of the injection of partially purified atrial natriuretic factor (ANF) and synthetic ANF (8-33) into rats with simultaneous infusions of dextrose or apr...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y84-105
更新日期：1984-06-01 00:00:00
abstract：:The turnover rate of glucose, the irreversible disposal rate of lactate, and the rate of gluconeogenesis from lactate were calculated by tracer methods in four normal and four alloxan-diabetic dogs under control conditions as well as in chronic, stable metabolic acidosis and alkalosis. Acidosis was produced by feeding...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y88-025
更新日期：1988-02-01 00:00:00
