ISSN:0009-7330    

出版商:OVID    

年代:1959

数据来源: OVID

摘要:

Coronary blood flow in the dog has been measured by the nitrous oxide desaturation method before and after acute bilateral cervical vagotomy, intravenous injection of atropine, and chronie sympathectomy. Vagotomy and atropine markedly increased coronary flow, myocardial oxygen consumption, and heart rate, but decreased left ventricular efficiency. Chronic sympathectomy resulted in the following smaller but statistically significant changes: a decrease in coronary flow, myocardial oxygen consumption, and heart rate, but an increase in left ventricular efficiency.Increasing the oxygen content of the arterial blood decreased the coronary flow. A comparison of diallylbarbiturate acid and urethane with morphine and chloralose anesthesia gave similar flow values, but cardiac efficiency was increased in the latter case.An analysis of the relationships between coronary flow, left ventricular oxygen consumption, and the arteriovenous oxygen difference is presented.

ISSN:0009-7330    

出版商:OVID    

年代:1959

数据来源: OVID

摘要:

Coefficients of correlation between coronary sinus blood flow and several cardiac variables have been analyzed from data obtained by the nitrous oxide desaturation method in dogs. Thervalue for flow and left ventricular oxygen consumption is an example of the correlation of two variables having a common element. The high values reported in the literature for this relationship may also be obtained with numbers drawn at random. Accordingly such values should not be accepted as valid evidence of a functional relationship between coronary blood flow and myocardial oxygen consumption.A high positive correlation, between flow and heart rate in the normal dogs and a significant inverse correlation between flow and arteriovenous oxygen difference in the chronic sympathectomized dogs, was observed.

ISSN:0009-7330    

出版商:OVID    

年代:1959

数据来源: OVID

摘要:

Right bundle branch block was produced in dogs, and activation of the free wall of the right ventricle was studied by means of multipolar electrodes. After block, accession spread radially at the earliest activated endocardial point and tangentially at later activated points. Direct current stimulation of selected endocardial points resulted in patterns of activation resembling those obtained after right bundle branch block in controls and after block. It is concluded that the Purkinje network does not participate in normal fashion in endocardial spread of the excitation impulse after right bundle branch block.

ISSN:0009-7330    

出版商:OVID    

年代:1959

数据来源: OVID

摘要:

Segments of both normal and atherosclerotic rabbit aortas were placed in the anterior chamber of host rabbits according to the Higginbotham technic. Normal aorta segments placed in the eyes of cholesterol fed rabbits quickly became infiltrated with fat and cholesterol. The intensity of this infiltration exceeded that observed in the host's own aorta. Atherosclerotic aorta segments placed in the eyes of normal rabbits quickly lost both lipid and cholesterol.

ISSN:0009-7330    

出版商:OVID    

年代:1959

数据来源: OVID

摘要:

Precordial potentials were synthesized from the components of the SVEC III vectorcardiographic system as an application of the Becking-Burger technic for testing the validity of the single dipole concept. The data was further utilized to construct Burger image loops from living subjects. Discrepancies from pure dipole theory and from the applicability of the SVEC III system are quantified. Limitations of even a perfect vectorcardiographic lead system are defined and discussed.

ISSN:0009-7330    

出版商:OVID    

年代:1959

数据来源: OVID

摘要:

Dogs were bled to a mean arterial pressure of 40 mm. Hg until 10 per cent of the shed blood had automatically reinfused from an elevated reservoir. The remaining blood was then rapidly infused intravenously. The procedure was fatal to all 13 dogs. Arterial blood epinephrine levels were followed during the time of hemorrhage and the post-hemorrhagic survival period in 9 of these animals. Arterial blood epinephrine levels in the 9 dogs increased from control values of less than one μg./L. to a maximum of 29 μg./L. during early hemorrhage, and then decreased during the period of spontaneous reinfusion to 7.5 μg./L. After complete reinfusion the blood pressure returned to normal, and epinephrine disappeared from the circulation. The blood pressure then gradually failed under normovolemic conditions, and the animals died in shock after an average of 220 minutes. Blood samples obtained immediately before death when the mean arterial pressure was 45 mm. Hg contained only 3.5 μg./L. epinephrine.

ISSN:0009-7330    

出版商:OVID    

年代:1959

数据来源: OVID

摘要:

Rats were rendered hypertensive by two different technics. Isometric tensions developed by strips of aorta from these rats, when exposed to various concentrations of epinephrine and levarterenol, were compared with those developed by aortic strips from normotensive controls. Almost all of the aortic strips from the DCA-salt hypertensive rats responded with smaller contraction tensions to both pressor agents than did the corresponding control strips from the normotensive animals. The same was true for most of the strips obtained from the renal hypertensive rats. These results do not lend support to the hypothesis that vascular hyperreactivity is the basis of many forms of hypertension.

ISSN:0009-7330    

出版商:OVID    

年代:1959

数据来源: OVID

摘要:

Testosterone in large doses in intact cholesterol-fed cockerels partially inhibited hypercholesteremia, without effecting aorta or coronary atherosclerosis. Castration, with and without testosterone administration in young male and female chicks, was without influence on hypercholesteremia and atherogenesis.

ISSN:0009-7330    

出版商:OVID    

年代:1959

数据来源: OVID

摘要:

The reported inhibition of fibrinolytic activity of blood plasma after ingestion of fat has been confirmed. It is shown that the chylomicrons present in such plasma are responsible for this phenomenon.

ISSN:0009-7330    

出版商:OVID    

年代:1959

数据来源: OVID