Quantitative histochemistry of late luteal phase human endometrium

New techniques are needed to evaluate the luteal phase endometrium in the infertility patient. Toward this goal, we have applied quantitative microbiochemical techniques to the determination of enzyme activities in microdissected samples of each endometrial cell type (i.e., epithelial and stromal) from individual endometrial biopsies. Preliminary data on eight control patients are presented to establish a normal range of epithelial and stromal lactate dehydrogenase (LDH), beta-hydroxyacyl-CoA-dehydrogenase (beta-OH-acyl-CoA-DH), and citrate synthase (CS) enzyme activities. Significantly higher enzyme activities were found in the epithelial cell type, compared with the stromal cell type for all three enzymes. Mean enzyme activities for the eight patients, comparing epithelial to stromal values, respectively, were (1) LDH, 39.9 versus 15.4; (2) CS, 4.0 versus 1.2; and (3) beta-OH-CoA-DH, 3.9 versus 2.3 mol/kgD/hour. Enzyme activities are expressed as moles of substrate reacting per kilogram dry weight per hour (mol/kgD/hour).