A Spectrophotofluorometric Micromethod for the Determination of Cortisol (Hydrocortisone) in Plasma and Tissue Obtained by Needle Biopsies

Abstract

A spectrophotofluorometric micromethod which allows the quantitative determination of cortisol in 30–70 mg tissue (sampled by needle biopsies) or 100 μ1 blood plasma is described. The method is evaluated for recovery, accuracy, precision and specificity, and is found to satisfy the expectations for a micromethod. Plasma cortisol is found within the range of values from the literature obtained by ordinary macro-scale methods. The concentration of cortisol in peripheral tissue (skin plus subcutaneous tissue) varies from 0–180 ng/g wet weight. Females around menopause have a lower tissue content than younger and older females and males, with no changes in the plasma concentration.