220
A. Vidal et al.
spectrometer (Thermo Fisher Scientific) with an electrospray interface, following
the method of Gerssen et al. (2009). The chromatographic separation was carried
out using a Gemini NX C18 column. The mobile phase consisted of 100 % water
(A) and acetonitrile: water (95:5 %) (B), both containing 2 mM ammonium formate
and 50 mM formic acid (pH 2.6). An isocratic elution consisting of a 10 % mobile
phase B and 90 % mobile phase A, was run. The mobile phase flow was 0.4 mL/min
and the injection volume was 20 L.
OA was quantified by comparison with reference materials from NRC-CRM,
Canada.
Results and Discussion
During our study three toxic episodes, caused by D. acuminata and D. acuta,
occurred between June 18, 2001 and August 6, 2002 (INTECMAR: www.intecmar.
org), during which our results showed that OA was accumulated by mussels
(Fig. 19.1). DTXs were not detected in any samples.
Considering all enzymatic activities evaluated, only CPR, GST, GR, GLO I,
GPXtot and CAT showed significant variations, which were related to the accumulation of OA in mussels.
The CPR activity showed a significant increase, mainly in males, inversely
related to decrease of OA accumulated (r: 0.375, p < 0.05) (Fig. 19.1a; Table 19.1).
This enzyme provides electrons to different oxygenases from the endoplasmic
reticulum, between them to the oxygenase- dependant cytochrome P450, which is
CPR
6000
4000
2000
0
1000
750
250
0
500
mUI/g tissue
OA (µg/kg)
GR
1800
1200
600
0
1000
750
250
0
500
mUI/g tissue
OA (µg/kg)
GPX-Tot
1600
1200
400
0
800
1000
750
250
0
500
mUI/g tissue
OA (µg/kg)
Jn Jl Au
Jl Au
S
O
2001
2002
Month/year
GST
12
8
4
0
1000
750
250
0
500
UI/g tissue
OA (µg/kg)
GLO I
16
12
4
0
8
1000
750
250
0
500
UI/g tissue
OA (µg/kg)
CAT
4500
3000
1500
0
1000
750
250
0
500
mUI/g tissue
OA (µg/kg)
Jn Jl Au
Jl Au
S
O
2001
2002
Month/year
a
b
c
d
e
f
Fig. 19.1 OA accumulation and variation of CPR, GST, GR, GPX, CAT and GLO I activities
from M. galloprovincialis digestive gland during three toxic episodes of D. acuminata. Bars:
concentration of OA accumulated in mussel soft tissues. Enzymatic activities in females () and
in males ()
A. Vidal et al.
spectrometer (Thermo Fisher Scientific) with an electrospray interface, following
the method of Gerssen et al. (2009). The chromatographic separation was carried
out using a Gemini NX C18 column. The mobile phase consisted of 100 % water
(A) and acetonitrile: water (95:5 %) (B), both containing 2 mM ammonium formate
and 50 mM formic acid (pH 2.6). An isocratic elution consisting of a 10 % mobile
phase B and 90 % mobile phase A, was run. The mobile phase flow was 0.4 mL/min
and the injection volume was 20 L.
OA was quantified by comparison with reference materials from NRC-CRM,
Canada.
Results and Discussion
During our study three toxic episodes, caused by D. acuminata and D. acuta,
occurred between June 18, 2001 and August 6, 2002 (INTECMAR: www.intecmar.
org), during which our results showed that OA was accumulated by mussels
(Fig. 19.1). DTXs were not detected in any samples.
Considering all enzymatic activities evaluated, only CPR, GST, GR, GLO I,
GPXtot and CAT showed significant variations, which were related to the accumulation of OA in mussels.
The CPR activity showed a significant increase, mainly in males, inversely
related to decrease of OA accumulated (r: 0.375, p < 0.05) (Fig. 19.1a; Table 19.1).
This enzyme provides electrons to different oxygenases from the endoplasmic
reticulum, between them to the oxygenase- dependant cytochrome P450, which is
CPR
6000
4000
2000
0
1000
750
250
0
500
mUI/g tissue
OA (µg/kg)
GR
1800
1200
600
0
1000
750
250
0
500
mUI/g tissue
OA (µg/kg)
GPX-Tot
1600
1200
400
0
800
1000
750
250
0
500
mUI/g tissue
OA (µg/kg)
Jn Jl Au
Jl Au
S
O
2001
2002
Month/year
GST
12
8
4
0
1000
750
250
0
500
UI/g tissue
OA (µg/kg)
GLO I
16
12
4
0
8
1000
750
250
0
500
UI/g tissue
OA (µg/kg)
CAT
4500
3000
1500
0
1000
750
250
0
500
mUI/g tissue
OA (µg/kg)
Jn Jl Au
Jl Au
S
O
2001
2002
Month/year
a
b
c
d
e
f
Fig. 19.1 OA accumulation and variation of CPR, GST, GR, GPX, CAT and GLO I activities
from M. galloprovincialis digestive gland during three toxic episodes of D. acuminata. Bars:
concentration of OA accumulated in mussel soft tissues. Enzymatic activities in females () and
in males ()