1. Phenol-glucuronide is a convenient substrate for
the assay of (ß-glucuronidase,using the Folin and
Giocalteu (1927) reagent for the estimation of free
2. ß-Glucuronidase from mouse liver, kidney and
spleen contains two fractions which may be separated by ammonium sulphate precipitation. Uterus
contains only one fraction. For total enzyme and
fraction B in liver,kidney and spleen a citrate
buffer at pH 5.2 was used in the estimation and for
uterine enzyme and fraction A in liver,kidney and
spleen a buffer at pH 4.5. A substrate concentration of 0.015M was used in all cases.
3. The mean recovery of added phenol in the assay
procedure was 100; ,and the standard deviat.ión of a single observation from the mean was 0.6%
4. The effect of menthol in increasing the glucuranidase activity in liver and kidney is secondary to
I repair following damage provoked by that agent
rather than due to its glucuronidogenic properties.
This is confirmed by the changes in enzyme activity
observed after administration of many nonglucuronidogenic compounds and by the manner in which the enzyme
activity reflected the sex -linked nature of chloroform poisoning in kidney.
5. The two enzyme fractions in liver and kidney
respond indifferently to agents causing changes in
the enzyme activity.
6. In uterus,as in other organs,changes in glucuronidase activity reflect changes in growth. The
action of oestrone on the enzyme is antagonised by
testosterone and progesterone.
7. Oestrone causes a marked increase in glucuronid&::
ase activity in liver accompanied by an increase in
cell division. Both effects may be antagonised by
testosterone and progesterone. Oesftadiol,oestriol
and oestriol- glucuronide,in doses comparable to that
of oestrone, are without effect on liver enzyme and
their action in stimulating mitosis is slight.
8. During liver regeneration,as after partial hepatectomy,uterine weight and glucuronidase activity
increaee_in ovariectomised mice in the absence of
administered oestrogen. Testosterone and progesterone antagonise this effect.
9. Colchicin.e,substituted stilbenes and anilines
and the antiolic acid factor,known to inhibit cell
proliferation,are without effect on the in vitro
hydrolysis of phenol -glucuronide by glucuronidase.
Saccharate,an efficient inhibitor of glucuronidase
in vitro,is without effect on mitosis.
10. Sorbic acid is a most efficient inhibitor of
11. A depression in the high glucuronidase level in
an organ in which mitosis had been stimulated is
only obtained after an inhibition of cell division.