摘要:

Potassium chloride, infused into 10 anesthetized dogs until severe electrical changes were observed in the heart (electrocardiogram) and serum potassium was elevated (9.5 mEq./L.), had no apparent effect on the glycogen content of any of the 4 heart chambers. Dog ventricular slices did not tolerate a medium high in potassium. Glycogenolysis was noted when the slices were incubated in a Krebs-Ringer buffered phosphate glucose medium containing 9 mM of potassium. The glycogen loss was confined to the acid-soluble form of the polysaccharide. A homogenate of dog myocardium, incubated in a simulated “intracellular” medium for up to 50 minutes, rapidly and continuously lost acid-soluble glycogen. The acid-insoluble fraction was not degraded until the homogenate was incubated for 50 minutes.

ISSN:0009-7330    

出版商:OVID    

年代:1961

数据来源: OVID

摘要:

Volume 8, page 821, table 1: aortic QO2should be corrected to read (μl. O2/hr./Gm. wet weight).

ISSN:0009-7330    

出版商:OVID    

年代:1961

数据来源: OVID

摘要:

A. series of experiments has been performed in which a standard dose of an artificial oil emulsion (Lipomul I.V.) was given to 5 groups of subjects and the disappearance of fat from their blood was observed by plasma optical density measurements. The groups were age-matched and consisted of a control group; 3 groups who had suffered a myocardial infarction and were respectively untreated, receiving heparin and receiving phenoprocoumon after recovery from the acute stage of the illness; and the last group which consisted of patients who suffered from intermittent claudication. The control, untreated infarct and peripheral vascular disease groups exhibited similar curves of optical density on time. The mean peak optical density was significantly lower in the heparin-treated than in the untreated group. Conversely, the mean peak optical density of the phenoprocoumontreated group was significantly higher than that of the untreated or control groups.

ISSN:0009-7330    

出版商:OVID    

年代:1961

数据来源: OVID

摘要:

The dynamics of vasovagal reactions which occurred in 2 patients during right heart catheterization were studied. Both subjects initially had systemic hypertension with corresponding increases in peripheral resistances. Subject B had considerably decreased blood flow, moderately elevated pulmonary artery and right ventricular end-diastolic pressures, and elevated central blood volume. These parameters were normal in subject A.The characteristic features of the reactions were appreciable declines in cardiac outputs coincident with decreased systemic arterial systolic, diastolic, and pulse pressures, decreased heart rates, and slight increases in calculated peripheral resistances. Stroke volumes were moderately reduced. A slight decrease in pulmonary artery systolic pressure occurred in subject A. In subject B, pulmonary artery and right ventricular enddiastolic pressures declined to normal and central blood volume decreased moderately. The return of heart rate to control values had no significant effects on the other physiologic parameters.The data demonstrate that reductions in cardiac output, due primarily to decreased stroke outputs, were predominantly responsible for the arterial hypotensions during the vasovagal reactions in these 2 subjects. The ineffectiveness of atropine in restoring hemodynamics in one subject suggested the importance of inhibition of efferent sympathetic activity in the etiology of this reaction. The failure of peripheral resistance to compensate for decreased blood flow suggested inhibition of arteriolar tone.

ISSN:0009-7330    

出版商:OVID    

年代:1961

数据来源: OVID

摘要:

In 68 healthy older men (mean age 59.5 years), the peak amplitude of impedance plethysmographic pulse tracings from the forehead increased significantly during hypoxia (breathing a 10 per cent O2, 90 per cent nitrogen mixture), while there was no significant change in a group of 58 healthy young men (mean age 23.4 years). The height of the dicrotic notch increased in the older men and decreased in the younger men. In both groups, the cycle length decreased, and the relative peak time increased significantly during hypoxia. The absolute peak time decreased in the older group and did not change in the younger group. The amplitude changes in hypoxia were related to the decrease of arterial oxygen saturation in the older, but not in the younger, men. It is suggested that hypoxia is a stronger stimulus for the reaction of extracranial circulation in older subjects.

ISSN:0009-7330    

出版商:OVID    

年代:1961

数据来源: OVID

摘要:

Oxygen uptake of aortas of young rats is higher than that of old rats in KRP solution. In serum of young rats, oxygen uptake and especially glucose uptake is higher than in serum of old rats in either young or old aortas. Anaerobic formation of lactic acid by the rat aorta is greater in serum of old rats than in serum of young rats. A fat-rich diet with 55 per cent butter fat, given for 6 weeks, significantly decreases oxygen and glucose uptake. This effect is not seen if soya oil is used instead of butter fat. A cholesterol-rich, atherosclerosis-producing diet decreases the glucose uptake. Norepinephrine, in vitro and in vivo, increases the oxygen and glucose uptake and the glycogen synthesis; epinephrine has no influence; acetylcholine decreases the oxygen and glucose uptake. The oxygen and glucose uptakes of aortic tissue from alloxandiabetic rats are lower than those from normal rats. Insulin in vitro increases oxygen and glucose uptake of the aorta in a Gey and Gey medium, this effect being greater in aorta of old rats.

ISSN:0009-7330    

出版商:OVID    

年代:1961

数据来源: OVID

摘要:

The resuscitated fetal human heart can be used as an experimental tool for the investigation of the excitatory process in the human heart. During perfusion the configuration of the epicardial electrocardiograms does not change appreciably. For accurate recording permitting a detailed analysis, the use of a high-fidelity oscillograph is absolutely necessary, otherwise no identification of the rapid portion of the intrinsic deflection can be made. The heart is suspended in an homogenous volume conductor at 37 C. and perfused with fluid matching as closely as possible the composition of the extracellular fluid.The morphology of the unipolar complexes is difficult to describe adequately. At the anterior side of the right and left ventricles rS complexes are found. Some parts of the left ventricular wall and posteroapical region of the left ventricle show QR complexes. In the area bordering the A-V groove one-third the distance from apex to basis, deep Q waves and even QS complexes are found. The relatively late intrinsic deflection here points to late excitation of this region. In regions neighboring the A-V groove, the Q wave diminishes in size and the R increases. The left posterior part of the left atrium is activated latest in the atrial cycle. The epicardial excitation pattern is surprisingly simple. The excitation wave reaches the region of attachment of the right anterior papillary muscle first, then spreads radially with varying velocity across the left ventricle towards the posterobasal region, while another wave spreads simultaneously across the right ventricle towards the same region. There is, therefore, a double envelopment of the epicardial surface. A comparison of the complexes having an intrinsic deflection occurring at the same time shows conclusively that, even over the same ventricle, the morphology of these complexes may be completely different. Thus the excitation time does not determine the morphology of the complexes. There is no typical right or left ventricular pattern. There appears to be no relationship between thickness of the heart wall and height of the R wave.

ISSN:0009-7330    

出版商:OVID    

年代:1961

数据来源: OVID

摘要:

Insulin and saline were injected into the right and left femoral arteries respectively of 19 alloxan-diabetes-mellitus dogs for 1 to 28 weeks. A significant increase of artery tissue cholesterol and total fatty acids was found on comparing the insulin-administered right leg with the saline-administered left leg. Similarly, a significant increase of total fatty acids in muscle was found on comparing the right with the left leg of the alloxan-diabetes mellitus dogs. No significant differences were observed in the normal animals when the insulin-injected side was compared with the noninjected.

ISSN:0009-7330    

出版商:OVID    

年代:1961

数据来源: OVID

摘要:

In a series of 11 dogs in which the left pulmonary artery was ligated, the blood from the occluded lung was absorbed by the remainder of the vascular bed and, consequently, there was no significant alteration in the pulmonary blood volume. This adaptation took place, apparently, with only slight modifications in the circulation time and the pressure of the system. Examination of the variables investigated suggests, to a certain extent, that the increased flow brings about the opening-up of new vascular channels.

ISSN:0009-7330    

出版商:OVID    

年代:1961

数据来源: OVID

摘要:

The effects of large amounts of various adrenal steroids on the electrocardiogram of the adrenalectomized dog are described. The changes which occurred most frequently fell into 2 major groups: (1) those following excess of mineralo-corticoids, e.g., desoxycorticosterone and aldosterone, and (2) those appearing after gluco-corticoid administration. A characteristic type of diphasic T wave frequently followed treatment with hydrocortisone and its analogs, and its correction was hastened by substituting mineralo-corticoid therapy.The 3 analogs of hydrocortisone (dexamethasone, prednisolone and triamcinolone) induce similar electrocardiographic patterns and after prolonged administration alter the P-Q interval in varying degrees, but more frequently produce a diphasic T. Dexamethasone preserves the normal pattern longer than the other steroids tested.

ISSN:0009-7330    

出版商:OVID    

年代:1961

数据来源: OVID