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Effect of cadmium and chromium on the intestinal absorption of glucose in the snakehead fish, Channa punctatus
~oxicoiogy Letters, 10 (1982) 293-296 Elsevier
Biomedical
293
Press
EFFECT OF CADMIUM AND CHROMIUM ON THE INTESTINAL ABSORPTION OF GLUCOSE IN THE SNAKEHEAD FISH,
CHANNA
PlJNCTA TUS
K.V. SASTRY
and Km. SUNITA
environmental Toxicology laboratory, De~arin~ent of Zoology, D..4. I/. {P.G.) CoBege, ~u~uffurnagur {India) (Received
August
13th, 1981)
(Accepted
August
21st, 1981)
SUMMARY The effect of five concentrations
of cadmium
0.001 mM) on the rate of absorption
tatus, was studied Maximum increase
decrease
at 23°C.
concentrations
examined;
and chromium
with
the highest
of’ cadmium
10 mM of cadmium.
of cadmium
(10 mM, 1 mM, 0.1 mM, 0.01 mM and
from the intestine
All concentrations
was recorded
in the concentration
of glucose
used.
Chromium
rate of absorption
fish, ~~ff~~a~~~~-
of the snakehead
decreased
the rate of glucose
The rate of transport increased
occurred
glucose
decreased
absorption
transport. with an rate at all
at 0.001 mM of chromium.
INTRODUCTION
Cadmium and chromium are important heavy metal water pollutants. The toxicity of cadmium to teleost fish is well documented. McCarty et al. [l] studied the toxicity of cadmium to gold fish, Carassias aerates, in hard and soft waters. Cadmium has been reported to produce hepatic storage alterations of vitamin Br2 in some freshwater fish [2], hypocalcemia in rainbow trout [3], locomotor hyperactivity in blue gill [4], inhibition of liver catalase activity in killifish, Fundulus heferocfitus [5], enhanced lysosomal activity in hepatic cells, [6] and blood dyscrasia in Colisa fasciatus [7]. Very little information is available on the toxic effects produced by chromium in teleosts. Buhler et al. [8] demonstrated high concentrations of chromium in opercular bone, spleen, kidney, gastrointestinal tract, and gall bladder of rainbow trout. Pickering [9] reported chronic toxic effects of chromium to fathead minnow (Pi~ephal#s promelas). Some quantity of heavy metals can enter the digestive system of fish through consumption of food-chain organisms and may produce disturbances in digestion and absorption of food. The present study was 0378-4274/82/0000-0000/$02.75
0 Elsevier
Biomedical
Press
294
undertaken to examine if cadmium and chromium produce any alteration tinal absorption of glucose in a freshwater fish, Channa punctahs.
MATERIALS
in intes-
AND METHODS
Channa punctatus (20 f 4 cm long; 70 f 10 g) were collected from local freshwater sources and maintained in laboratory glass aquaria. Fish were allowed to acclimatize to laboratory corditions for one week. Five concentrations (10 mM, 1 mM, 0.1 mM, 0.01 mM and 0.001 mM) of cadmium and chromium in KrebsRinger-bicarbonate solution containing 40 mM of glucose were prepared. Intestinal sacs were filled with these solutions according to the method of Musacchia and Bramanate [lo]. In control fish glucose solution alone was used. The luminal fluids of both experimental and control fish were collected after 1 h at 23 “C. The concentration of glucose in the recovered solutions was determined by the method of Park and Johnson [l 11. The dry weight of the intestines was recorded by keeping the tissues at 100°C until the weight became constant. The f-test described by Fisher [12] was employed to estimate the significance of differences between control and experimental
RESULTS
values.
AND DISCUSSION
Heavy metals like mercury, lead and cadmium are widely distributed in freshwater sources and are harmful to aquatic fauna. Heavy metals can enter the body of fish through the food and may affect digestion and absorption of food material. In the present study transport of glucose by the intestine of Channa punctatus was reduced by inclusion of cadmium in the instilled solution. All five concentrations of cadmium produced significant decreases in the rate of absorption of glucose, but the decreases were not proportional to the increases in the cadmium concentrations (Table I). Further, the decreases in the rate of transport of glucose were more marked in the cadmium concentration range of l-10 mM. Sugar and amino acid transport through the intestine is carrier-mediated. According to Newcomer [13], a protein carrier in the cell membrane binds with amino acid and sodium and then transports the two across the cell membrane, releasing them into the cytoplasm. Csaky [14] and Alvarado [15] have suggested a common carrier mechanism for amino acids and sugars in the intestine. Transport of sugar by carrier protein is sodium-dependent [16]. Heavy metals due to their strong affinity for ligands like phosphate and the cysteinyl and histidyl side chains of proteins, can bind with carrier protein molecules resulting in inhibition of sugar and amino acid transport. Miller et al. [17] have shown that transport of glucose from 2-day- and 21-day-old chick jejunum is markedly reduced by mercuric chloride. Further evidence for inhibition of glucose transport by heavy metals comes from the work of Wapnir et al.
295
[18], who demonstrated inhibition of intestinal glucose transport in rats that received 20 mg of lead acetate kg body weight. In contrast to cadmium, all five concentrations of chromium increased the rate of glucose absorption by the intestine of Channa punctatus (Table II). The rate of glucose transport was highest at 0.001 mM of chromium. Increases in concentrations of chromium in the medium gradually decreased the rate of absorption; this indicated that lower concentrations of chromium are more effective in producing elevated glucose absorption rates. Contrary to the present findings, Stokes and Fromm [19] reported inhibition of glucose uptake by intestinal epithelial cells of rainbow trout exposed to chromium. The mechanism of increased intestinal glucose transport in Crania ~unctatus exposed to chromium is not clear from the present study and deserves further investigation.
TABLE
I
EFFECT
OF CADMIUM
CHANNA
PVNCTA
ON THE RATE OF TRANSPORT
OF GLUCOSE
BY THE INTESTINE
OF
TUS. Rate of transport &mol glucose
Cont.
absorbed/g
dry weight/h)
of n
Control
Experimental
IO
18
14.10 * 0.33
IO.80 rt: 0.45b
1
18
12.19 + 0.20
10.05 + 0.26b
0.1
I4
11.65 f 0.35
9.70 t 0.17a
0.01
14
12.91 + 0.17
11.33 + 0.40a
0.001
18
10.28 + 0.10
cadmium (mM)
Values are mean + SE.;
TABLE EFFECT
9.60 + o.lOb
-
aP < 0.01; bP < 0.001.
II OF CHROMIUM
OF CHANNA
ON THE RATE OF TRANSPORT
OF GLUCOSE
BY THE INTESTINE
PVNCTATVS Rate of transport (pmol glucose
absorbed/g
dry weight/h)
COW. of chromium
n
Control
10
22
10.07 + 0.24
11.09 jr 0.24a
1
22
9.24 t 0.30
10.36 t 0.28a
0.1
19
8.07 k 0.24
9.62 +- 0.22”
0.01
18
8.75 k 0.20
10.85 + 0.45a
7.66 k 0.14
11.22 It O.lob
Experimental
(mM)
0.001 _..
--
20
Values are mean + S.E.; aP ~0.01;
--
bP < 0.001.
296
K.V.S.
is grateful
Award’,
to the University
and to the authorities
Grants
of D.A.V.
Commission, College,
New Delhi for a ‘Career
Muzaffarnager
for facilities.
REFERENCES
1 L.S. McCarty,
J.A.C.
Henry and A.H.
IUS, in hard and soft water, 2 M. Merlini, Contam.
Hepatic
Toxicol,
Toxicity
storage
alteration
Can.,
of vitamin
of cadmium
fish, Curassiurn ULUW
togold
35 (1978) 35.
Bt: by cadmium
in freshwater
fish, Bull. Environ,
19 (1978) 767.
3 M. Roth and E.J. Maly, Relationship trout
Houston,
J. Fish, Res. Board
of cadmium-induced
(.Srt/nro gffjr~~er~~and the influence
hypocalcemia
of temperature
on toxicity,
with mortality
in rainbow
J. Fish. Res. Board
Can.,
36
(1979) 1297. 4 E.G.
Ellgard,
J.E.
Tusa,
chirus, hyperactivity Biol.,
and F.R. Engelhardt,
production
and
cadmium,
N. Mache,
Srivastava, Buhler,
9 Q.H.
Lysosomal
J. Comp.
R.M.
chromium
Pickering,
Stokes
10 X.J. Musacchia, hybernation,
and
R.S.
catalase
Chronic
toxicity
inhibition
and cadmium cadmium
thionein
exposure,
Mar.
and M.J.
13 A.D.
Newcomer,
14 T.Z.
Csaky,
Johnson,
Digestion
Transport
15 F. Alvarado, Science,
Toxicol.,
and A.Y. Bramanate,
fish induced
Tissue
accumulation
and
enzymatic
goircineri), .I. Fish. Res. Board Can.,
with
chromium
to the fathead
effects
of
34 (1977) 9.
(~i~~e~b~~~s
minnow
of third international
symposium
on mammalian
1967. analysis
of sugars,
in S.P. Colowick
and N.O.
Kaplan
Vol. 111, Academic Press, New York, 1963, pp. 86-87. for Research Workers, I Ith ed., Oliver and Boyd. London,
and absorption
of protein,
biological
of sugars
by
9 (1980) 405.
Proceedings
Calorimetric
through
Transport
cells of a teleost
fish, Coiisa.fa.fciufus, associated
in a teleost
of hexavalent
Contam.
in hepatic
Caldwell, (Salmu
Oliver and Bopd, Edinburgh,
J.T. Park,
membranes.
and aminoacids
Mayo Clin. Proc., Annu.
Rev. Physiol.,
in the intestine,
1950.
48 (1973) 624.
evidence
27 (1965) 415. for a common
carrier,
151 (1966) 1010.
Crane,
G. Forstner
and A. Eichholz,
.X. An effect of Na+
concentration
in vitro,
Studies
concentration
Biochim.
17 D.A. Miller, A.T. Shehata
Biophys.
and J. Lerner,
rats after
S. Moak,
F. Lieshitz
intraperitoneal
Stokes, Physiol.
injections
and P.O. Zool.,
Fromm,
on the mechanism
on the apparent Acta,
(II) chloride
J. Pharmacol.
and S. Teichberg, of lead acetate, Effects
38 (1965) 202.
Michaelis
of intestinal constant
absorption
for intestinal
of sugar
109 (1965) 647.
Mercury
tissue from 2 day and 21 days chicks,
18 R. Wapnir,
trout.
and zinc, .I. Fish.
89 (1979) 609.
trout
(Eds.), Methods in Enzymology, 12 R.A. Fisher, Statistical Methods
19 R.M.
chromium
4 (1980) 357.
Blood dyscrasia Pathol.,
in rainbow
prornekzs), Arch. Environ.
jejunal
uptake,
enhancement
Reports),
and S. Mishra,
poisoning,
hexavalenr
sugars,
LeporrGs macro-
of the blue-gill
heteroclitus) induced by experimental
Cell Biol. (International
cadmium
I6 R.K.
activity
of cadmium,
Res., 3 (1980) 101.
6 S. Ferri,
II
Locomotor
concentrations
Liver cadmium
in the Killifish (Fundulus
Environ.
8 D.R.
Malizia,
by sublethal
12 (1978) 25.
5 R.J. Pruell,
7 A.K.
and A.A.
induced
Alterations J. Lab. Clin.,
of chromate
inhibition
Exp. Ther.,
on glucose
of n-glucose
transport
in
214 (1980) 101.
of intestinal
and renal functions
in
94 (1979) 144. transport
by the gut of rainbow
Biomedical
293
Press
EFFECT OF CADMIUM AND CHROMIUM ON THE INTESTINAL ABSORPTION OF GLUCOSE IN THE SNAKEHEAD FISH,
CHANNA
PlJNCTA TUS
K.V. SASTRY
and Km. SUNITA
environmental Toxicology laboratory, De~arin~ent of Zoology, D..4. I/. {P.G.) CoBege, ~u~uffurnagur {India) (Received
August
13th, 1981)
(Accepted
August
21st, 1981)
SUMMARY The effect of five concentrations
of cadmium
0.001 mM) on the rate of absorption
tatus, was studied Maximum increase
decrease
at 23°C.
concentrations
examined;
and chromium
with
the highest
of’ cadmium
10 mM of cadmium.
of cadmium
(10 mM, 1 mM, 0.1 mM, 0.01 mM and
from the intestine
All concentrations
was recorded
in the concentration
of glucose
used.
Chromium
rate of absorption
fish, ~~ff~~a~~~~-
of the snakehead
decreased
the rate of glucose
The rate of transport increased
occurred
glucose
decreased
absorption
transport. with an rate at all
at 0.001 mM of chromium.
INTRODUCTION
Cadmium and chromium are important heavy metal water pollutants. The toxicity of cadmium to teleost fish is well documented. McCarty et al. [l] studied the toxicity of cadmium to gold fish, Carassias aerates, in hard and soft waters. Cadmium has been reported to produce hepatic storage alterations of vitamin Br2 in some freshwater fish [2], hypocalcemia in rainbow trout [3], locomotor hyperactivity in blue gill [4], inhibition of liver catalase activity in killifish, Fundulus heferocfitus [5], enhanced lysosomal activity in hepatic cells, [6] and blood dyscrasia in Colisa fasciatus [7]. Very little information is available on the toxic effects produced by chromium in teleosts. Buhler et al. [8] demonstrated high concentrations of chromium in opercular bone, spleen, kidney, gastrointestinal tract, and gall bladder of rainbow trout. Pickering [9] reported chronic toxic effects of chromium to fathead minnow (Pi~ephal#s promelas). Some quantity of heavy metals can enter the digestive system of fish through consumption of food-chain organisms and may produce disturbances in digestion and absorption of food. The present study was 0378-4274/82/0000-0000/$02.75
0 Elsevier
Biomedical
Press
294
undertaken to examine if cadmium and chromium produce any alteration tinal absorption of glucose in a freshwater fish, Channa punctahs.
MATERIALS
in intes-
AND METHODS
Channa punctatus (20 f 4 cm long; 70 f 10 g) were collected from local freshwater sources and maintained in laboratory glass aquaria. Fish were allowed to acclimatize to laboratory corditions for one week. Five concentrations (10 mM, 1 mM, 0.1 mM, 0.01 mM and 0.001 mM) of cadmium and chromium in KrebsRinger-bicarbonate solution containing 40 mM of glucose were prepared. Intestinal sacs were filled with these solutions according to the method of Musacchia and Bramanate [lo]. In control fish glucose solution alone was used. The luminal fluids of both experimental and control fish were collected after 1 h at 23 “C. The concentration of glucose in the recovered solutions was determined by the method of Park and Johnson [l 11. The dry weight of the intestines was recorded by keeping the tissues at 100°C until the weight became constant. The f-test described by Fisher [12] was employed to estimate the significance of differences between control and experimental
RESULTS
values.
AND DISCUSSION
Heavy metals like mercury, lead and cadmium are widely distributed in freshwater sources and are harmful to aquatic fauna. Heavy metals can enter the body of fish through the food and may affect digestion and absorption of food material. In the present study transport of glucose by the intestine of Channa punctatus was reduced by inclusion of cadmium in the instilled solution. All five concentrations of cadmium produced significant decreases in the rate of absorption of glucose, but the decreases were not proportional to the increases in the cadmium concentrations (Table I). Further, the decreases in the rate of transport of glucose were more marked in the cadmium concentration range of l-10 mM. Sugar and amino acid transport through the intestine is carrier-mediated. According to Newcomer [13], a protein carrier in the cell membrane binds with amino acid and sodium and then transports the two across the cell membrane, releasing them into the cytoplasm. Csaky [14] and Alvarado [15] have suggested a common carrier mechanism for amino acids and sugars in the intestine. Transport of sugar by carrier protein is sodium-dependent [16]. Heavy metals due to their strong affinity for ligands like phosphate and the cysteinyl and histidyl side chains of proteins, can bind with carrier protein molecules resulting in inhibition of sugar and amino acid transport. Miller et al. [17] have shown that transport of glucose from 2-day- and 21-day-old chick jejunum is markedly reduced by mercuric chloride. Further evidence for inhibition of glucose transport by heavy metals comes from the work of Wapnir et al.
295
[18], who demonstrated inhibition of intestinal glucose transport in rats that received 20 mg of lead acetate kg body weight. In contrast to cadmium, all five concentrations of chromium increased the rate of glucose absorption by the intestine of Channa punctatus (Table II). The rate of glucose transport was highest at 0.001 mM of chromium. Increases in concentrations of chromium in the medium gradually decreased the rate of absorption; this indicated that lower concentrations of chromium are more effective in producing elevated glucose absorption rates. Contrary to the present findings, Stokes and Fromm [19] reported inhibition of glucose uptake by intestinal epithelial cells of rainbow trout exposed to chromium. The mechanism of increased intestinal glucose transport in Crania ~unctatus exposed to chromium is not clear from the present study and deserves further investigation.
TABLE
I
EFFECT
OF CADMIUM
CHANNA
PVNCTA
ON THE RATE OF TRANSPORT
OF GLUCOSE
BY THE INTESTINE
OF
TUS. Rate of transport &mol glucose
Cont.
absorbed/g
dry weight/h)
of n
Control
Experimental
IO
18
14.10 * 0.33
IO.80 rt: 0.45b
1
18
12.19 + 0.20
10.05 + 0.26b
0.1
I4
11.65 f 0.35
9.70 t 0.17a
0.01
14
12.91 + 0.17
11.33 + 0.40a
0.001
18
10.28 + 0.10
cadmium (mM)
Values are mean + SE.;
TABLE EFFECT
9.60 + o.lOb
-
aP < 0.01; bP < 0.001.
II OF CHROMIUM
OF CHANNA
ON THE RATE OF TRANSPORT
OF GLUCOSE
BY THE INTESTINE
PVNCTATVS Rate of transport (pmol glucose
absorbed/g
dry weight/h)
COW. of chromium
n
Control
10
22
10.07 + 0.24
11.09 jr 0.24a
1
22
9.24 t 0.30
10.36 t 0.28a
0.1
19
8.07 k 0.24
9.62 +- 0.22”
0.01
18
8.75 k 0.20
10.85 + 0.45a
7.66 k 0.14
11.22 It O.lob
Experimental
(mM)
0.001 _..
--
20
Values are mean + S.E.; aP ~0.01;
--
bP < 0.001.
296
K.V.S.
is grateful
Award’,
to the University
and to the authorities
Grants
of D.A.V.
Commission, College,
New Delhi for a ‘Career
Muzaffarnager
for facilities.
REFERENCES
1 L.S. McCarty,
J.A.C.
Henry and A.H.
IUS, in hard and soft water, 2 M. Merlini, Contam.
Hepatic
Toxicol,
Toxicity
storage
alteration
Can.,
of vitamin
of cadmium
fish, Curassiurn ULUW
togold
35 (1978) 35.
Bt: by cadmium
in freshwater
fish, Bull. Environ,
19 (1978) 767.
3 M. Roth and E.J. Maly, Relationship trout
Houston,
J. Fish, Res. Board
of cadmium-induced
(.Srt/nro gffjr~~er~~and the influence
hypocalcemia
of temperature
on toxicity,
with mortality
in rainbow
J. Fish. Res. Board
Can.,
36
(1979) 1297. 4 E.G.
Ellgard,
J.E.
Tusa,
chirus, hyperactivity Biol.,
and F.R. Engelhardt,
production
and
cadmium,
N. Mache,
Srivastava, Buhler,
9 Q.H.
Lysosomal
J. Comp.
R.M.
chromium
Pickering,
Stokes
10 X.J. Musacchia, hybernation,
and
R.S.
catalase
Chronic
toxicity
inhibition
and cadmium cadmium
thionein
exposure,
Mar.
and M.J.
13 A.D.
Newcomer,
14 T.Z.
Csaky,
Johnson,
Digestion
Transport
15 F. Alvarado, Science,
Toxicol.,
and A.Y. Bramanate,
fish induced
Tissue
accumulation
and
enzymatic
goircineri), .I. Fish. Res. Board Can.,
with
chromium
to the fathead
effects
of
34 (1977) 9.
(~i~~e~b~~~s
minnow
of third international
symposium
on mammalian
1967. analysis
of sugars,
in S.P. Colowick
and N.O.
Kaplan
Vol. 111, Academic Press, New York, 1963, pp. 86-87. for Research Workers, I Ith ed., Oliver and Boyd. London,
and absorption
of protein,
biological
of sugars
by
9 (1980) 405.
Proceedings
Calorimetric
through
Transport
cells of a teleost
fish, Coiisa.fa.fciufus, associated
in a teleost
of hexavalent
Contam.
in hepatic
Caldwell, (Salmu
Oliver and Bopd, Edinburgh,
J.T. Park,
membranes.
and aminoacids
Mayo Clin. Proc., Annu.
Rev. Physiol.,
in the intestine,
1950.
48 (1973) 624.
evidence
27 (1965) 415. for a common
carrier,
151 (1966) 1010.
Crane,
G. Forstner
and A. Eichholz,
.X. An effect of Na+
concentration
in vitro,
Studies
concentration
Biochim.
17 D.A. Miller, A.T. Shehata
Biophys.
and J. Lerner,
rats after
S. Moak,
F. Lieshitz
intraperitoneal
Stokes, Physiol.
injections
and P.O. Zool.,
Fromm,
on the mechanism
on the apparent Acta,
(II) chloride
J. Pharmacol.
and S. Teichberg, of lead acetate, Effects
38 (1965) 202.
Michaelis
of intestinal constant
absorption
for intestinal
of sugar
109 (1965) 647.
Mercury
tissue from 2 day and 21 days chicks,
18 R. Wapnir,
trout.
and zinc, .I. Fish.
89 (1979) 609.
trout
(Eds.), Methods in Enzymology, 12 R.A. Fisher, Statistical Methods
19 R.M.
chromium
4 (1980) 357.
Blood dyscrasia Pathol.,
in rainbow
prornekzs), Arch. Environ.
jejunal
uptake,
enhancement
Reports),
and S. Mishra,
poisoning,
hexavalenr
sugars,
LeporrGs macro-
of the blue-gill
heteroclitus) induced by experimental
Cell Biol. (International
cadmium
I6 R.K.
activity
of cadmium,
Res., 3 (1980) 101.
6 S. Ferri,
II
Locomotor
concentrations
Liver cadmium
in the Killifish (Fundulus
Environ.
8 D.R.
Malizia,
by sublethal
12 (1978) 25.
5 R.J. Pruell,
7 A.K.
and A.A.
induced
Alterations J. Lab. Clin.,
of chromate
inhibition
Exp. Ther.,
on glucose
of n-glucose
transport
in
214 (1980) 101.
of intestinal
and renal functions
in
94 (1979) 144. transport
by the gut of rainbow