Abstract:
:Changes in angiotensin-converting enzyme were measured in the lungs of fetal rabbits isolated and perfused in situ at varying ages from 22 days gestation to 7 days of age under controlled conditions of flow, pH, and temperature. Enzyme activity was assessed by infusing bradykinin or angiotensin I in Krebs-Henseleit solution and measuring residual peptide in the effluent by radioimmunoassay. The levels of substrate studied were below those required for enzyme saturation. Lungs of 22 day gestation fetuses removed only one-third of either peptide. The activity at term and in neonatal life resulted in more than 80% peptide removal. The time of the greatest rise in the percent substrate cleared occurs earlier than the time of the greatest increase in lung and body weight. The lower percentage of substrate cleared in early gestation appears to result in part from a limited surface area for enzyme activity in the primitive fetal pulmonary microvascular bed, since morphological studies with fluorescein-tagged anticonverting enzyme antibody demonstrated the presence of enzyme in the lung as early as 17 days of gestation. Electron micrographs of the pulmonary endothelial cell surface reveal that the degree of surface infolding and hence surface area increases with gestation. The higher percentage of substrate cleared in later gestation closely parallels the structural and ultrastructural development of the vascular bed. The presence of converting enzyme in the placenta by the second third of gestation and the large size of the placenta suggest that this organ may be a major locus of converting enzyme activity in the fetus.
journal_name
Circ Resjournal_title
Circulation researchauthors
Stalcup SA,Pang LM,Lipset JS,Odya CE,Goodfriend TL,Mellins RBdoi
10.1161/01.res.43.5.705subject
Has Abstractpub_date
1978-11-01 00:00:00pages
705-11issue
5eissn
0009-7330issn
1524-4571journal_volume
43pub_type
杂志文章,收录出版abstract::Ryanodine receptor (RyR) phosphorylation by protein kinase A (PKA) may be important in modulating resting sarcoplasmic reticulum (SR) Ca2+ release, especially in heart failure. However, clear cellular data on PKA-dependent modulation of cardiac RyRs is limited because of difficulty in distinguishing between PKA effect...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/hh0302.105660
更新日期:2002-02-22 00:00:00
abstract::In intact porcine aorta, endothelium-derived nitric oxide released on thrombin stimulation inhibits the concomitant production of endothelin. Experiments were designed to examine the effect of hirudin (which inactivates thrombin) and the nitrovasodilators nitroglycerin and 3-morpholinosydnonimine on the spontaneous an...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.68.6.1768
更新日期:1991-06-01 00:00:00
abstract::Oxidized low-density lipoproteins increase arginase activity and reciprocally decrease endothelial NO in human aortic endothelial cells. Here, we demonstrate that vascular endothelial arginase activity is increased in atherogenic-prone apolipoprotein E-null (ApoE(-/-)) and wild-type mice fed a high cholesterol diet. I...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/CIRCRESAHA.107.169573
更新日期:2008-04-25 00:00:00
abstract:RATIONALE:Elevations in C-reactive protein (CRP) are associated with increased cardiovascular disease risk and endothelial dysfunction. CRP antagonizes endothelial nitric oxide synthase (eNOS) through processes mediated by the IgG receptor Fcγ receptor IIB (FcγRIIB), its immunoreceptor tyrosine-based inhibitory motif, ...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/CIRCRESAHA.111.254573
更新日期:2011-10-28 00:00:00
abstract::An affinity gel for the purification of renin was prepared by coupling pepstatin to aminohexylagarose gel. Partially purified human renin (Haas et al., Arch. Biochem. Biophys., 110, 534-543, 1965) was purified further by affinity chromatography on the pepstatin-aminohexyl-agarose gel, gel filtration on a Sephadex G-75...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.41.4.4
更新日期:1977-10-01 00:00:00
abstract::Atrial fibrillation (AF) may result from stationary reentry in the left atrium (LA), with fibrillatory conduction toward the right atrium (RA). We hypothesize that periodic input to the RA at an exceedingly high frequency results in disorganized wave propagation, compatible with fibrillatory conduction. Simultaneous e...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.0000022854.95998.5c
更新日期:2002-06-14 00:00:00
abstract::This paper describes use of the Karhunen-Loeve expansion to identify and reduce temporal redundancy in electrocardiographic body surface potential maps (192 body surface leads recorded simultaneously at 1 kHz/channel for approximately 600 msec). Temporal data compression of about 20 to 1 was obtained with accurate rep...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.49.1.197
更新日期:1981-07-01 00:00:00
abstract::To determine the relative roles of cardiac and sinoaortic baroreceptors in mediation of arginine vasopressin (AVP) release, hemorrhage was performed in five groups of conscious splenectomized dogs: 1) all nerves intact; 2) either chronic surgical or acute pharmacological (intrapericardial lidocaine) cardiac denervatio...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.68.5.1422
更新日期:1991-05-01 00:00:00
abstract::A narrow zone of block in isolated false tendon preparations was created by perfusion of the central compartment (gap) of a three-compartment tissue bath with either an isotonic sucrose solution or a solution designed to mimic the extracellular milieu in ischemic tissue. Driven responses on the proximal side of the ga...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.49.5.1129
更新日期:1981-11-01 00:00:00
abstract:RATIONALE:Cardiac remodeling and subsequent heart failure remain critical issues after myocardial infarction despite improved treatment and reperfusion strategies. Recently, cardiac regeneration has been demonstrated in fish and newborn mice after apex resection or cardiac infarctions. Two key issues remain to translat...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/CIRCRESAHA.115.307017
更新日期:2016-01-22 00:00:00
abstract::In the mammalian myocardium, potassium (K(+)) channels control resting potentials, action potential waveforms, automaticity, and refractory periods and, in most cardiac cells, multiple types of K(+) channels that subserve these functions are expressed. Molecular cloning has revealed the presence of a large number of K...
journal_title:Circulation research
pub_type: 杂志文章,评审
doi:10.1161/hh2301.100349
更新日期:2001-11-23 00:00:00
abstract::Whereas numerous studies have investigated the role of prostacyclin and thromboxane A2 in the maintenance of coronary blood flow, most of these have focused on normal vessels. In the present investigation, we examined the prostaglandin- and thromboxane-synthesizing capacity of isolated coronary artery segments obtaine...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.57.2.223
更新日期:1985-08-01 00:00:00
abstract::Many indices have been proposed to describee the diastolic pressure-volume curve mathematically and permit quantification of the elastic properties of the myocardium itself in hopes that changes in the muscle caused by disease would b.e reflected in the diastolic pressure-volume curve. To date, none of the proposed in...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.39.6.772
更新日期:1976-12-01 00:00:00
abstract::This study examines the cellular basis and specificity of the effects of adenosine on early afterdepolarizations (EADs), delayed afterdepolarizations (DADs), and triggered activity (TA) induced by various drugs with different mechanisms of action. Membrane potential and currents were measured in isolated guinea pig ve...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.70.4.743
更新日期:1992-04-01 00:00:00
abstract::Trimetazidine is a clinically effective antianginal agent that has no negative inotropic or vasodilator properties. Although it is thought to have direct cytoprotective actions on the myocardium, the mechanism(s) by which this occurs is as yet undefined. In this study, we determined what effects trimetazidine has on b...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.86.5.580
更新日期:2000-03-17 00:00:00
abstract::The bioactivity of nitric oxide (.NO) depends, in part, on its interaction with superoxide. Usually, superoxide dismutase (SOD) preserves .NO bioactivity by limiting the availability of superoxide. Ascorbic acid also effectively scavenges superoxide, but the extent to which this interaction is necessary for intact .NO...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.83.9.916
更新日期:1998-11-02 00:00:00
abstract::Baroreceptor reflexes can be demonstrated during fetal life, but whether baroreceptors normally regulate fetal arterial pressure is unknown. This problem was addressed directly by measuring arterial pressure and analyzing its variation in eight unanesthetized fetal lambs throughout the last third of gestation, and com...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.52.5.580
更新日期:1983-05-01 00:00:00
abstract::High sodium intake (HNa) increases brain ouabainlike activity (OLA) in rats. In spontaneously hypertensive rats (SHR), HNa exaggerates development of hypertension and pressor and sympathoexcitatory responses to stress. To investigate whether dietary sodium-induced changes in brain OLA play a functional role, responses...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.70.2.430
更新日期:1992-02-01 00:00:00
abstract::The potential for exogenous infusion of basic fibroblast growth factor (bFGF) to increase collateral blood flow to dependent tissue was quantified in adult male rats with peripheral arterial insufficiency. Occlusion of the femoral artery at a proximal site did not infringe on resting blood flow to the distal hindlimb ...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.79.1.62
更新日期:1996-07-01 00:00:00
abstract::If the control of infectious diseases was the public health success story of the first half of the 20th century, then the decline in mortality from coronary heart disease and stroke has been the success story of the century's past 4 decades. The early phase of this decline in coronary heart disease and stroke was unex...
journal_title:Circulation research
pub_type: 杂志文章,评审
doi:10.1161/CIRCRESAHA.116.309115
更新日期:2017-01-20 00:00:00
abstract:RATIONALE:Inhibition of glycogen synthase kinase-3 (GSK-3) protects the heart during ischemia/reperfusion (I/R), yet the underlying mechanisms of cardioprotection afforded by beta isoform-specific inhibition GSK-3 remain to be elucidated. OBJECTIVE:We studied the molecular mechanism mediating the effect of GSK-3β acti...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/CIRCRESAHA.111.249532
更新日期:2011-08-19 00:00:00
abstract:RATIONALE:We previously reported that type VI collagen deposition increases in the infarcted myocardium in vivo. To date, a specific role for this nonfibrillar collagen has not been explored in the setting of myocardial infarction (MI). OBJECTIVE:To determine whether deletion of type VI collagen in an in vivo model of...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/CIRCRESAHA.111.252734
更新日期:2012-03-16 00:00:00
abstract::Glibenclamide, one of the antidiabetic sulfonylureas, is known to block ATP-dependent K+ channels. We used this drug to determine to what extent K+ loss from acutely ischemic myocardium is mediated via these channels. We also investigated whether glibenclamide would influence ischemic arrhythmias. Isolated rat hearts ...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.66.2.478
更新日期:1990-02-01 00:00:00
abstract::This article examines the role of innervation in regulating expression of acetylcholinesterase (AchE), butyrylcholinesterase (BuchE), and the muscarinic acetylcholine receptor (mAchR) in avian heart. Two distinct approaches are taken. The first approach examines the relation between the onsets of parasympathetic and s...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.70.4.633
更新日期:1992-04-01 00:00:00
abstract::Ischemia/reperfusion (I/R) affects the integrity of the endoplasmic reticulum (ER), the site of synthesis and folding of numerous proteins. Therefore, I/R may activate the unfolded protein response (UPR), resulting in the induction of a collection of ER stress proteins, many of which are protective and function to res...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.RES.0000220643.65941.8d
更新日期:2006-05-12 00:00:00
abstract:RATIONALE:Aortic valve disease is a cell-mediated process without effective pharmacotherapy. CNP (C-type natriuretic peptide) inhibits myofibrogenesis and osteogenesis of cultured valve interstitial cells and is downregulated in stenotic aortic valves. However, it is unknown whether CNP signaling regulates aortic valve...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/CIRCRESAHA.117.311194
更新日期:2018-02-02 00:00:00
abstract::Mononuclear phagocytes (MPs) relevant to atherosclerosis include monocytes, macrophages, and dendritic cells. A decade ago, studies on macrophage behavior in atherosclerotic lesions were often limited to quantification of total macrophage area in cross-sections of plaques. Although technological advances are still nee...
journal_title:Circulation research
pub_type: 杂志文章,评审
doi:10.1161/CIRCRESAHA.114.301174
更新日期:2014-05-23 00:00:00
abstract::Herein, we show that the paired-related homeobox gene, Prx1, is required for lung vascularization. Initial studies revealed that Prx1 localizes to differentiating endothelial cells (ECs) within the fetal lung mesenchyme, and later within ECs forming vascular networks. To begin to determine whether Prx1 promotes EC dif...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.RES.0000130656.72424.20
更新日期:2004-06-11 00:00:00
abstract::Previous studies have suggested that intravenous infusion of arginine vasopressin (AVP) inhibits sympathetic nerve activity (SNA) in rabbits by its action at the brainstem. This study aimed to determine, first, whether this action of AVP depended on functioning baroreflex mechanisms. The second aim was to determine th...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.65.5.1390
更新日期:1989-11-01 00:00:00
abstract::Cardiomyocyte hypertrophy is transcriptionally controlled and inhibited by glycogen synthase kinase 3beta (GSK3beta). Myocardin is a muscle-specific transcription factor with yet unknown relation to hypertrophy. Therefore, we investigated whether myocardin is sufficient to induce cardiomyocyte hypertrophy and whether ...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.RES.0000184684.88750.FE
更新日期:2005-09-30 00:00:00