Medical Research Society
Non-malignant mucosa and tumour tissue from
azoxymethane injected rats showed marked and
characteristic chanaes in sialidase activitv.
Activity &ole/h/mg protein
normal
n non-malig. n tumour
n
ffi
0.015f0.01 9 0.02f0.01 6 0.53f0.27 6
WIG
0.11f0.06 9 0.10f0.07 6 1.35f0.71
6
GA
1.46f0.61 9 0.91i0.36 6 0.06f0.02 4
SL
0.63f0.39 9 0.60f0.29 6 1.79f0.75 6
The dramatic increase of sialidase activity
against MG and decrease of activity against GA
in tumour tissue may s e m e as tumour markers
in this system.
'
5 4 QUANTITATION OF FAECAL SULPHATASE IN
ULCERATIVE COLITIS AND NORMAL CONTROLS
J.M. RHODES, R, GALLIMORE, E. ELIAS AND
J.F. KENNEDY
Department of Medicine, Queen Elizabeth
Hospital, Birmingham and Department of
Chemistry, University of Birningham
Histochemical studies show a reduction in
colonic sulphomucins in active ulcerative colitis (UC) (Ehsanullah et al, Gut 1932:485-89).
One possible explena'iionmight be desulphation
by sulphatoses produced by colonic bacteria.
We have therefore measured faecal sulphatase
activity in patients with UC and normal controls.
Faeces were collected from 6 patients with
inactive UC, 6 with active UC and € normal
controls. Aliquots from each sample were homogenized in 0.22M Tris acetate buffer at pH's
5.5, 6.5, 7.5 and 8.5, centrifuged for 30 min
at 15000g and the supernatants filtered through
0.22um filters to obtain bacteria-free filtn8tes
Sulphatase activity in these filtrates was
assayed fluorimetrically after 10 min incubation
at 37OC with 4me-umbelliferyl sulphate (K salt)
as substrate. Enzyme activity was expressed as
units/g pellet wt. where 1 unit=lpmol of 4meumbelliferone released/min at 37OC.
Sulphatase activity was detectable in 5/6
normal faeces and 11/12 UC faeces. In all samples greatest activity was at pH 8.5 (normals
0.68iu/g 5 0.90 sd, inactive UC 0.3050.34,
active UC2.20i3.54). At lower pH there was
little sulphatase activity in the normal faeces
(0.09+0.09at pH 7.5, 0.05+0.08 at pH 6.5 and
0.03+o.08 at pH 5.5) but in UC, although the
optimal pH'was 8 . 5 in all samples, considerable
activity was present at lower pH (active UC
0.7221.06 at pH 7.5, 0.1250.19 at pH 6.5 and
0.03+0.06 at pH 5.5; inactive UC 0.1550.13 at
pH 7.5. 0.04+0.06 at pH 6.5, 0.01+0.03 at pH5.5)
Considerable sulphatase activity is present in
most faeces. It has an alkaline pH optimum but
some activity at physiorogical pH and stool pH
(spprox 6.5). There is a trend towards increased
Caecal sulphatase activity in active UC,particularly at physiological pH,which may expiain the
mucus desulphation demonstrable histochemically.
Since sulphation increases mucus resistance to
degradation this could be pathogenically
important in UC.
55P
1.5 5 a(-DEXTRINASE HAS NEGLIGIBLE MALTASE ACTIVITY
IN VIVJ: A CONTRADICTORY FINDING
HELEN M. 'BARKER, JEAN E. CANFIELD AND R.H. TAYLOR
Department of Gastroenterology and Nutrition,
Central Middlesex Hospital, London NU10
Brush border hydrolysis of sucrose is known to
be catalysed only by the sucrase moiety of the
nybrid enzyme sucrase-M-dextrinase (sucraseisomaltase). By contrast the relative
contributions of brush border ccglucoamylascs
and the sucrase and edextrinase moieties o f
'sucrase-#-dextrinase to the hydrolysis of
maltose are less clear. UD to 50% of maltase
activity has been attributed to w-dextrinase
(Gray, 1975: N Eng J Med 292, 1225-30). In the
present study a selective competitive inhibitor
of brush border #-glucoamylases and sucrase
(Truscheit et al, 1981: Angew Chem (Int Ed) g,
744-611, acarbose, which has negligible
inhibitory effect on otdextrinase in vitro, has
been used to determine the fractional
contribution of c<-dextri nase catalysed ma1 tose
hydrolysis in vivo.
A 20cm segmeTitof proximal jejunum was
perfused at 0.271111 min-' in 28 adult anaesthetised rats. The solution contained either maltose
or sucrose 11.7mnol 1 - I , 'NaCl 147mnol 1-' and
PEG 4000 39 1-' labelled with lpCi 1% and
included acarbose 30mg 1-' in the second 4h in
half the animals. After Bh equilibration, 10min
collections were taken and analysed for sugars,
electrolytes and PEG concentration. This
concentration of enzyme inhibitor resulted in a
maximal reduction in sucrose disa+pearance rate
of 89?12% (p<O.OOl, n=7) whereas maltose
disappearance rate was reduced by 60:7% (p<0.001,
n=7) under the same conditions.
These results suggest that in vivo most
maltase activity must be due t m c o a m y l a s e s
and sucrase, which are strongly inhibited by
acarbose in vitro. The contribution of
K-dextrinase, which is hardly inhibited by
acarbose, appears to be negligible. Thus
O(-dextrinase appears to have no appreciable
inaltase activity in vivo in this model.
Ue gratefully acknowledge support frorli
lie k'ki1coti.a Tius'; ax! Bayer (M) Ltd.
1 5 6 QnANl'ITATIVE ASSEsSKEWI OF HEPATIC VOLUMES
IN ALCOHOLIC LIVXB DISEASE
N. LE!JNC, K. WARD, P. FARRANF, H.MEZREAND
T.J. PmEW
Divisions of Clinical Cell Biology and Radiology
MRC Clinical Research Centre, Harrow, Middlesex.
Liver size is generally considered to be enlarged in alcoholic liver disease but clinical
assessment is largely subjective and serial
measurements of hepatic volume by ultrasonography have not been previously reported.
Liver volume measurements were performed at
11.00 13.00 hrs with a static B mode ultrasound scanner. Longitudinal s-le
sweep scans
were taken at 1 cm intervals from the tip of the
-