摘要:

The hemodynamic effects of closed-chest extracorporeal circulation were investigated in normal dogs and in dogs subjected to coronary embolization. In both groups, despite delivery of large volumes of blood into the abdominal aorta through peripheral routes, a rise in proximal aortic pressure could not be achieved; to accomplish this it was necessary to increase vascular resistance by balloon obstruction of the lower abdominal aorta, the distal aorta being supplied with superior vena cava blood. The resulting rise in proximal aortic pressure was accompanied by a diminution in calculated left ventricular work.

ISSN:0009-7330    

出版商:OVID    

年代:1960

数据来源: OVID

摘要:

The aerobic metabolism of homogenates of normal and ischemic left ventricle was compared in dogs at various time intervals (15 min. to 24 hours) after high ligation of the circumflex branch of the left coronary artery. Glucose and fructose-1,6-diphosphate were used as substrates. The injured tissue was taken from the posterior papillary muscle (PP) and the non-ischemic tissue from the anterior superior septum (LV). Both oxygen consumption and organic phosphorus (Δ organic phosphorus) were slightly decreased in PP at 15 and 30 min. after ligation. Between 30 and 60 min., there was a sharp decrease in oxygen consumption and Δ organic phosphorus falling to 40 to 50 per cent of control values at 60 min. A further decrease was observed at 180 min., and at 24 hours there was a complete loss of oxidative metabolism in the PP. A striking increase in organic phosphorus metabolism and oxygen consumption was observed in the non-ischemic portion of the myocardium 60 and 180 min. after ligation.

ISSN:0009-7330    

出版商:OVID    

年代:1960

数据来源: OVID

摘要:

A high fat meal was given to 78 volunteers. Total esterifled fatty acid, cholesterol, and lipase levels were determined in a fasting blood specimen and in specimens obtained 3 and 6 hours after the meal. Attempts were made to correlate the fat tolerance of the individual with the level of fat splitting enzymes in the various serum specimens. The influence of Pancreatic Hormone, whole pancreatic preparations, secretin, and heparin on the fat tolerance as well as on the lipase level was determined. Attempts were made to correlate the findings of fat tolerance and glucose tolerance tests done on the same individuals.

ISSN:0009-7330    

出版商:OVID    

年代:1960

数据来源: OVID

摘要:

Molar sodium lactate, sodium bicarbonate, sodium chloride, glucose insulin, and calcium chloride were used in the treatment of induced hyperkalemia in nephrectomized dogs. The effect of these agents on the electrocardiogram and on potassium partition was studied. Molar sodium lactate appeared to be the agent of choice in the treatment of the hyperkalemic state under these experimental conditions.

ISSN:0009-7330    

出版商:OVID    

年代:1960

数据来源: OVID

摘要:

Adult mongrel dogs were given a lethal dose of E. Coli endotoxin by rapid intravenous injection. Total serotonin levels in the serum fell rapidly, with the concentration in the portal vein and pulmonary artery significantly exceeding that in the femoral artery within the first minute after injection. Small rises in plasma serotonin were found in some of the animals. These changes were coincident with a sharp fall in the number of circulating platelets, with striking changes in platelet morphology, and with the initial fall in blood pressure.

ISSN:0009-7330    

出版商:OVID    

年代:1960

数据来源: OVID

摘要:

When 7 × 10−7M tetraethylpyrophosphate (TEPP) was administered as constant perfusion, the results were: (1) A progressive slowing of atrial rate and subsequent block in conduction; (2) A decrease in slope of the prepotential of pacemaker fibers; (3) No significant change in membrane resting potential of sinoatrial and atrial fibers, even during block in conduction; (4) An accelerated repolarization of both types of fibers. Simultaneously with the changes in electrical activity TEPP consistently produced a progressive decrease in inotropism. Pyridine 2-aldoxime methiodide (PAM) in concentrations of 1.26–2.52 × 10−4M consistently reversed the effects of TEPP. The inotropism often exceeded the control. The data suggests that 1) the changes in transmembrane potential produced by TEPP are principally due to an acetylcholine action, 2) the decrease in contractility is more intimately related to a disturbance in metabolic energy, and 3) the reversibility of the TEPP effects by PAM is due to a reactivation of acetylcholinesterase, an action similar to that observed in vitro.

ISSN:0009-7330    

出版商:OVID    

年代:1960

数据来源: OVID

摘要:

The effect of quinidine on unidirectional fluxes of Na and K in isolated rabbit atria has been investigated and correlated with known effects of the drug on the electrical and mechanical properties of the heart. Quinidine caused a rapid inhibition of Na entry, which secondarily depressed K efflux. In addition, the drug depressed membrane permeability to K and caused a marked inhibition of active transport, both of which were relatively slow in onset.

ISSN:0009-7330    

出版商:OVID    

年代:1960

数据来源: OVID

摘要:

Cineradiographic studies on the cardiovascular system in snakes form the basis of this report. The method provides anatomical informations at the functional level and differs greatly from classical anatomical studies. The physiological interpretations involve timing of the various heart phases and the active role of the right atrium during ventricular filling. The snake ventricle has an incomplete septum and the admixture problem is discussed, as are also some considerations regarding the pulmonary circulation and the reserve mechanism of the snake heart.

ISSN:0009-7330    

出版商:OVID    

年代:1960

数据来源: OVID

摘要:

Pressure-volume relationships and myocardial oxygen consumption (V˙O2) were obtnined in an isolated heart during ventricular fibrillation, potassium-induced arrest, and isovolumetric contractions. The heart was found to be less distensible in fibrillation than in diastole or arrest. The V˙O2increased from 4.6 to 14.6 cc./100 Gm. LV/min. as the fibrillating ventricle was distended. During arrest the V˙O2remained constant despite ventricular distention. When the fibrillating ventricle was distended beyond a critical point coronary flow was compromised and the V˙O2decreased. Beyond and only beyond this point could the V˙O2be increased by the greater coronary flow induced by a higher perfusion pressure.

ISSN:0009-7330    

出版商:OVID    

年代:1960

数据来源: OVID

摘要:

By autoradiography it has been demonstrated that parenterally administered S35as sulfate is localized in the area of arterial plaque formation in rabbits with induced atherosclerosis. Dialysis of such tissue, after fat extraction to rid the tissue of inorganic sulfate, shows a much larger amount of sulfate remaining in the aortas of diseased animals as compared to controls suggesting that it is in combination with the mucopolysaccharides of the artery.

ISSN:0009-7330    

出版商:OVID    

年代:1960

数据来源: OVID