DETERMINATION OF BLOOD AND PLASMA VOLUMES, THIOCYANATE SPACE, AND BROMSULFALEIN CLEARANCE IN RATS

Abstract

Methods are described for the simultaneous detn. of blood and plasma vol., thiocyanate space and bromsulfalein clearance which are suitable for use with rats. In agreement with previous investigators, Evan''s Blue dye utilized for the detn. of blood and plasma volumes was uniformly distributed in the blood before the lapse of 5 min. after injn. Thiocyanate also appears to have been uniformly distributed after 5 min. although 10 min. were allowed as a matter of precaution. Rats have a great ability to remove bromsulfalein In rats of the same size (equal blood vol.), the rate of removal from the blood during the first 20 min. after injection is such that concn. at X time is a constant; correction may thus be made for variations in the time when blood samples are taken. With rats of 60-400 g. in wt., the clearance from the blood per 100 g. of body wt. was directly related to the dose per 100 g. of body wt.