A B S T R A C T Assay conditions have been developed for the determination of urinary 8-glucuronidase, ,8-galactosidase, a-galactosidase, and, -hexosaminidase using fluorometric substrates. The assay conditions for ,8-glucuronidase overcome interference by both low and high molecular weight inhibitors, a problem that has confused earlier studies of enzyme excretion.The fouir lysosomal enzymes are excreted coordinately; although their absolute levels (in units per milligram of creatinine) vary during the day and from one day to the next, the ratio of one enzyme to another remains relatively constant. The lack of correlationi between plasma aind urine enzyme levels, together with the high molecular weights of these enzymes, suggests that the urinary enzymes are not derived by glomerular filtration. The lack of coordinacy with lactate dehydrogenase suggests they are not derived from exfoliated cells. By analogy with experimental animals, they' may be derived from lysosomes extruded into the lumnen of the proxinmal tubule by epithelial cells.There is considerable variation among a poptulation of 125 healthy adult subjects for total enzyme exeretionl. Both total enzyme excretion and coordinacy ratios are log-normially' distributed, suggesting that they are the resuiltants of many factors, each of which has a relative, or proportional, effect on enzyme excretion. About one-half the population variation resides in a process common to the exeretion of all four enzymes (possibly the lsosomiie extruisioni pathway'), and about one-half r-esides in factors affectiing each enzviye independently.

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Acid hydrolases are present in normal human urine in appreciable amounts. Their source appears to be lysosomes released by kidney proximal tubule epithelial cells. For a given lysosomal enzyme the total amount excreted is the product of two parameters, a general one describing the rate of lysosome secretion and a specific one describing the relative concentration of that enzyme in lysosomes. There is considerable population variation in both parameters. Studies of beta-glucuronidase, beta-galactosidase, beta-hexosaminidase, and alpha-galactosidase in monozygotic and dizygotic twins show that an appreciable part of this variation is genetic in origin. This appears to be true for both total enzyme excretion and lysosome composition. Although it was not possible to test directly whether this is also true for the rate of lysosome secretion, the fact that the two former parameters are both heritable strongly suggests that the rate of lysosome excretion is also a heritable trait. Taken together with previous data, the results suggest polygenic control of these biochemical traits. It is particularly significant that beta-glucuronidase excretion in normal individuals is a heritable trait since the excretion of this enzyme has frequently been used as a measure of normal and pathological physiological changes.

8Hosr AGE ti DNA PRECURSORS ON STAPHYLOCOCCI liver are not able to remove the specific antibodies from the serum.Discussion. Homologous testes antisera contain antibodies that localize with the achrosome of the spermatid and the head of spermatozoa. This specific localization occurs in the testes of sensitized as well as unsensitized animals. I t would appear, therefore, that the autoantigen constituent of testes extracts resides in this cytological component. This finding confirms by fluorescent technics the suggestion of Freund et al. ( 1) and Katsh( 5 ) that aspermatogenic antigen may be a polysaccharide associated with the achrosome. The results are in agreement also with those of Baum(8) whose pictures indicate localization of fluorescence in the mature sperm but do not permit identification of specific cytological regions. The low grade fluorescence we observe in the albuguinea and blood vessel walls can be expected on the basis of previous experiments. I t has been shown that normal serum proteins deposit to a limited extent in the extra-vascular connective tissue structures ( 9 ) . Further evidence for the specificity of fluorescent localization in the spermatid achrosomes and sperm head is provided by the absorption experiments in which lyophylized guinea pig testes are effective in removing antibodies while liver and kidney extracts are not. The lack of correla-tion between circulatory levels of antibodies and morphologic damage to the testes is similar to the results reported by other investigators and points to the fact that much remains to be elucidated with respect to the mechanisrna of the immunological insult to the testes as well as the chemical identification of antigens involved in the induction of asperma t ogenesis.