Serum alkaline DNase activity in normal or nonhospitalised individuals.

According to previous observations, the variations in serum alkaline DNase activity (SADA) appeared to be useful in monitoring malignant disease. In this study, SADA was measured in 625 individuals to explore nontumor-related factors which may influence SADA levels. The overall range in SADA was 0.2-82.3 kU/l. Women aged 50-79 years had higher (p less than 0.001) levels of SADA than younger females. A similar but less consistent effect of age was noticed in men (0.01 less than p less than 0.05). Older men had lower (0.01 less than p less than 0.05) SADA levels than the older women. Old women substituted with estrogens had lower (0.01 less than p less than 0.05) levels of SADA than those not treated with estrogens. SADA levels in pregnancy as well as postparturition were lower (p less than 0.001) than SADA values in nonpregnant females of similar age. In fertile women, no SADA variation was observed during the menstrual cycle and there was no significant effect of contraceptive pills. In males, SADA seemed unrelated to testosterone or cortisol levels but varied during the day. Smoking, alcohol consumption and drug therapy appeared to be without effect on SADA.