Quantification of protein thiols in morphologically intact cells of the cervical epithelium. II. Effects of cell differentiation.

Protein-SH-groups (PSH) were determined quantitatively in basal (B), parabasal (P), intermediary (I) and superficial (S) cells of normal portio epithelium in order to obtain information about the correlation between PSH and cell differentiation. It was found that total PSH increase from B to S by 67 per cent, the main step occuring from B to P. Nuclear PSH drop continuously from B to S by 80 per cent. Thus, cytoplasmic PSH must raise (by 400%). The area of the increases strongly from B to S (by more than 1000%). Thus, differentiation is accompained by a drastic "dilution" of total PSH and PSH per area unit (1 micron2) both of nuclear and cytoplasm drop considerably. The findings about nuclear PSH are interpreted in terms of the loss of proliferative activity during differentiation, about cytoplamic PSH as expression of decreasing activities of PSH depending metabolic processes.