Page 124 - 《水产学报》2025年第10期

李森栋，等 水产学报, 2025, 49(10): 109609

[35]
brain liver ment of lipid metabolism under a microscope . It
a
2 000 DMSO b b b was shown that small droplets stained by ORO were
1 500
mRNA relative expression 200 5 mg/kg d de c c c c the control group (Fig.10-a,b), while the lipid
1 mg/kg
dispersally distributed in hepatocytes of fish liver of
1 000
3 mg/kg
500
150
droplets were larger and stained in darker red in
100
those of the physical stimulus treated groups (Fig.
50
10
10-c,d). This suggested that the extern stress
0 5 de de de de e de triggered the lipid accumulation and disordered the
lipid metobolism in darkbarbel catfish liver. On the
mapk8b crhr1 nr3c2 iars1
(a) contrary, in the dietary WS groups, the lipid droplets
40 were stained in light red color (Fig. 10-e —h),
a
implying the lipid metabolism in liver were obvi-
ously enhanced and lipid accumulation were
30 decreased by dietary WS in darkbarbel catfish.
COR/(ng/mL) 20 b analysis revealed that the PCNA expression was
Moreover, the immunofluorescence staining

10 b stronger (Fig. 11-a,b) and the proportion of the
PCNA-positive cells was significantly higher in the
c
dietary WS groups than the basic dietary groups or
0 control groups (P < 0.05) (Fig. 11-c).

DMSO 1 mg/kg 3 mg/kg 5 mg/kg
(b) 3 Discussions
Fig. 6 The related genes and serum cortisol level regu-

lated by intramuscular injection of Withanolide A in
3.1 The stress and immune responses allevi-
young darkbarbel catfish
ated by dietary WS in darkbarbel catfish
Totally, 5 groups of fish, 10 pieces in each group, were used. One group
was set as blank without any treatment, one group as the control group
Stress is commonly occurred in aquaculture
(injected with equal volume of 0.1% DMSO), and the fish of other 3
and always significantly affect the health and pro-
groups were injected with Withanolide A at different dose (1, 3, 5 mg/kg:
[6]
Withanolide A was dissolved in dimethyl sulfoxide (DMSO) for the ductivity of farmed fish species . The physiolo-
stock solution at 100 mg/mL, then diluted by sterile normal saline to pre- gical and biochemical responses to stress are regu-
pare a working solution for injection). The fish were treated by intramus-
lated by several systems and molecular signaling
rd
st
th
cular injection on the 1 , 3 , 5 day and sacrificed for samples collection
th
on the 7 day. Briefly brain and liver were collected for genes’ expres- pathways, including the HPA axis, immune system,
sion by qPCR, the serum samples were for examination of cortisol level and oxidative stress [36-38] . These pathways play a cru-
by ELISA kit. (a) The mRNA expression analysis of Target genes by
cial role in modulating the overall health and adapt-
qPCR, including mapk8b, crhr1, nr3c2 mRNA expression level in the
ability of fish under stressful conditions [39-41] . It was
brain tissues and iars mRNA expression in liver tissues. (b) The serum
cortisol (COR) level in fish of different groups. Different letters indicate found that activation of the HPA axis could sup-
the significant differences (P < 0.05), and the same letters for no signific-
press immune and inflammatory responses because
ant difference.
the cortisol, as a key stress hormone, can inhibit lots
[42]
2.8 Lipid Metabolism and PCNA Expression of immune components of immune response . In
regulated in Liver the present study, in the darkbarbel catfish, the
physical stimuli triggered strong stress response and
ORO is always utilized to detect neutral lipids,
modulated a series of genes associated with immune
such as triglycerides, in tissue sections by staining regulation and neuronal signaling, such as csf1a and
lipids red or orange-red, thus facilitating the assess- grin1b, were significantly upregulated in response
https://www.china-fishery.cn 中国水产学会主办 sponsored by China Society of Fisheries
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