HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Mixner, J. P. Articles by Anderson, R. R. Search for Related Content PubMed Articles by Mixner, J. P. Articles by Anderson, R. R.

Phenolsulponphthalein Fractional Clearance in Dairy Cattle as a Measure of Renal Function¹

New Jersey Agricultural Experiment Station, Sussex

ABSTRACT

A new test for renal function in dairy cattle has been devised, based on the rate of clearance of phenolsulfonphthalein (PSP or phenol red) from the blood and body fluids by the kidneys. Two bull calves and two lactating cows were used in these experiments, in which PSP was injected intravenously. The blood plasma level of PSP was determined at various time intervals after the injection. The plasma level of PSP fell rapidly at first and less rapidly thereafter. The over-all curve of plasma levels was differentiated into two first-order regressions in which the logs_e of PSP concentration were inversely and rectilinearly related to the time after PSP injection. The first regression was theorized to represent the rate at which PSP moved from the plasma into other body fluids (collectively, its volume of distribution), with a mean slope value in the four animals of 0.171 per min. and a mean biological half-time of 4.4 min. The second regression was theorized to represent the rate at which PSP was eliminated from its volume of distribution (mean of 36.9% of body weight) by the kidneys and has been termed PSP fractional clearance. It is defined as that fraction of the total volume of distribution of PSP which is cleared of the dye per minute on an instantaneous basis. The mean PSP fractional clearance for the four animals was 0.0298, with a mean biological half-time of 24.5 min. PSP fractional clearance is easily measured and is considered to be a dynamic measure of renal function.

¹ Paper of the Journal Series, New Jersey Agricultural Experiment Station, Rutgers University, the State University of New Jersey, Department of Dairy Industry, New Brunswick. This work was supported in part by a grant from Merck Sharpe & Dohme Research Laboratories, Division of Merck & Company, Rahway, New Jersey.