Serum and urinary N-acetyl-beta-D-glucosaminidase activity among the inhabitants of a rural area in Japan--the effect of age and hypertension.

In this paper, the normal values, distribution, and variations in serum and urinary activities of the lysosomal enzyme, N-acetyl-beta-D-glucosaminidase (NAG), were estimated in a rural area of Japan. The frequency distribution of NAG activities both in the serum and urine of 1,152 males and females (aged 35 to 87), living in a rural area of Gifu Prefecture in Japan, showed an approximately log-normal distribution. Geometric mean values (with S.D. ranges) in healthy subjects (876 males and females) were 12.61 U/l (9.56-16.63) for serum NAG and 8.05 U/l (4.03-16.07) for urinary NAG. There was no significant difference between those of males and females. Serum and urinary NAG activities increased with advancing ages, and these NAG activities in hypertensive subjects were higher than those in normotensives. Since the serum and urinary levels of several commonly measured cytosolic chemicals were within normal limits, the above results could not be ascribed to tissue necrosis. Thus, the estimation of serum and urinary NAG could be a useful indicator discriminating the essential hypertensive patients from the normal subjects.