Peripheral venous monitoring with acute blood volume alteration: cuff-occluded rate of rise of peripheral venous pressure.

We investigated the use of a new peripheral hemodynamic monitoring technique, the cuff-occluded rate of rise of peripheral venous pressure (CORRP), in the assessment of volume status in fluid overload. Seven adult mongrel dogs were given a general anesthetic, and monitoring lines were inserted. The animals were then subjected to an incremental volume overload of approximately 13% of estimated initial blood volume at 5-min intervals until a total volume infusion nearly equal to the animal's initial blood volume was reached. Comparison of the various monitoring techniques (e.g., cardiac output, CVP, systemic BP, pulmonary wedge pressure) demonstrated that the peripheral measurement of CORRP had better correlation with known administered volume (r = .96) than any of the other variables. The sensitivity of each of the variables in assessing small amounts of volume overload was also studied. The volume of crystalloid infusion necessary to cause a clinically significant change (defined as greater than 2 SD above the baseline mean) was compared for each of the monitoring variables. CORRP was equivalent to the other variables in sensing early volume overload. In summary, in the anesthetized animal model CORRP appears to be a sensitive, minimally invasive method of assessing volume status in acute volume overload. The efficacy of CORRP in a canine hemorrhagic shock and reperfusion model had previously been demonstrated. This technique could be clinically applicable in situations such as trauma with hemorrhagic shock, intraoperative volume changes, and in the assessment of intravascular volume after resuscitation.

The purification and characterization of human kidney L-arginine:glycine amidinotransferase.

Human kidney L-arginine:glycine amidinotransferase (transamidinase) has been purified to a homogeneous state as defined by native and sodium dodecyl sulfate gel electrophoresis and by ultracentrifugation (sedimentation equilibrium) experiments. The four steps in the isolation procedure were chromatography with DEAE-cellulose, gel filtration with Sephadex G-150, chromatography with phenyl Sepharose, and high-pressure liquid chromatography with hydroxylapatite. The final product represented a 90-fold purification of the enzyme. Human kidney transamidinase is a dimer with a molecular mass of 89,000 Da and subunit masses of 44,000 Da. The Km for arginine and glycine were both 2.5 mM and the Vmax was 0.5 mumol ornithine/min/mg protein. The ultraviolet absorption spectrum, specific activity, and isoelectric points were determined for human kidney transamidinase. Multiple forms of the enzyme were obtained by isoelectric focusing. Human kidney transamidinase cross-reacted with polyclonal antibodies raised to rat kidney transamidinase. All of the properties of human kidney transamidinase that we have examined were similar to those of rat kidney transamidinase. A close evolutionary relationship between the rat and human kidney transamidinase is suggested.