RED CELL, PLASMA, AND BLOOD VOLUME IN HEALTHY WOMEN MEASURED BY RADIOCHROMIUM CELL-LABELING AND HEMATOCRIT*

Abstract

In a previous study of 201 healthy men (1), red cell volume (Vrbc) was measured by a modification of Sterling and Gray's radiochromium method (2), and whole blood and plasma volumes (Vwb and Vpl) were derived from venous he- miatocrits.The influence of factors other than body size on the variance of the data was studied, and standards for predicting normal volumes were derived.The present report describes a similar examination of 101 women. SUBJECTS AND METHODSThe women, all of whom volunteered for study, were actively employed as housewives, laboratory personnel, nurses, or office workers, and most were white (Table I).None were taking medications regularly or were subject to dietary control other than mild voluntary caloric restriction, and none were pregnant.Although some engaged in sports regularly, none were trained athletes.All had been living at sea level for at least a year.Cases of gross clinical obesity were not included.No subject was a regular blood donor, and none had given blood within 10 weeks.Health screening tech- niques included a medical history, physical examination, chest X-ray, and urinalysis.A hematocrit below 37 per cent, the limit of normal as defined by Wintrobe (3), caused exclusion of only one volunteer.In no subject was the arterial blood pressure over 140 mm Hg systolic or 90 mm Hg diastolic.The method' of labeling the autologous cells with NaCr5O4 and of determining their volume of distri- bution (VCr"1) was as described in the study on men (1, 4).Tests were performed before breakfast or, rarely, in the afternoon when lunch had been omitted.Subjects lay down for at least 30 minutes before the labeled cells were delivered and until sampling was completed no less than 35 minutes later.