Simultaneous Measurement Of Changes Research Articles

Estimation of the protein concentration of the capillary filtrate by an isotope technique.

AbstractA method for direct estimation of the protein content of the capillary filtrate during venous congestion and muscular exercise is descr bed. The volume changes of the calf muscles of the cat are recorded plethysmo‐graphically. Changes in the albumin content of the calf are recorded by external monitoring of the activity from intravenously injected radioactive iodinated human serum albumin. Corrections for changes of activity due to variations in regional blood volume are made possible by the simultaneous measurement of changes of the activity from Cr51‐labelled erythrocytes. The difficulties and errors of the method are discussed. The protein content of the capillary filtrate is low both during venous congestion and exercise, about 0.3 g/100 ml or less than 10 % of that of plasma.As a control of the method the protein content of the filtrate formed during continuous intraarterial infusion of histamine was also studied. In these experiments the protein concentration of the capillary filtrate rose to as much as 75% of that in plasma.

Longitudinal and radial strain in pulse wave transmission.

Simultaneous measurements of changes in aortic length, circumference and pressure reveal that at the beginning of systole aortic lengthening precedes the increased aortic circumference and pressure. Slight differences which were observed between circumference and pressure may be accounted for by longitudinal motion and by instrumental artifacts. The concept of active rhythm contraction of the vessel walls is not regarded as necessary to explain any of the observed phase differences between aortic pressure and dimensions.