Transcript How Se and C affect fish health

How Se and C affect Fish
Health
John Emil Halver
School of Aquatic & Fishery Sciences
University of Washington; Seattle, WA.
C FUNCTIONS IN FISH HEALTH
Hydroxylation of procollagen
Hydroxylation of tryptophan
Intracellular reducing agent
Hydroxylation of steriods
Erythrocyte maturation
Rapid wound repair
Serum iron binding
Resistance to Vibrio
Mixed function oxidases
Enhanced phagocytic index
Resistance to Edwardsiella
Enhanced antibody production
A-C-E-Se axis
Ascorbate roles in metabolism
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PROLINE --> HYDROXYPROLINE
TRYPTOPHAN --> SERATONIN
TYROSINE --> NOREPINEPHRINE
OSTEOBLASTS --> WOUND REPAIR
VASO-HUMORAL --> BLOOD FLOW
TOXICANTS -->MIXED Fn OXIDASES
STEROIDS -->STEROLS
Fe3+ -->Fe2+
Cu2+ -->Cu1+
Se4+ --> Se2+
CHOLESTEROL -> BILE ACIDS
Proline to Hydroxyproline
The amino acid proline is hydroxylated through the
reducing action of ascorbic acid in the presence of
ferrric ion to form hydroxyproline, which is polymerized
to form the fiberous structure of tissue membranes.
Tryptophan to Seratonin
Ascorbic acid provides the reducing agent to convert
tryptophan to the hormone seratonin.
Tyrosine to Norepinephrine
Ascorbic acid also provides the reducing factor to convert tyrosine
to the hormone norepinephrine.
Osteoblasts in Wound repair
Osteoblasts are the first cells formed in tissue wound repair, and
cellular restructure. Ascorbic acid is involved in the synthesis of
hydroxyproline amino acid that is a major component of the
cellular membrane.
Vaso-humoral structure and
Blood flow
The elastic characteristics of the vascular system are determined
by the hydroxyproline constituants, which are dependent upon
ascorbate reserves during formation of the fiberous tissues.
Toxicants and Mixed Function
Oxidases
The first tissue reaction to toxicants is hydroxylation of the chemical
compounds involved. The mixed function oxidases require
ascorbate in the oxidation-reduction process involved.
Steroids and Sterols
The conversion of steroids to sterols involves ascorbic acid in the
hydroxylation in the oxidation reduction process involved.
Ferric to Ferrous ions
Ascorbic acid is a reducing agent for the conversion of ferric to
ferrous ions.
Cuppric to cupprus ions
Ascorbic acid acts as a reducing agent to change copper state in
compounds involved in intermediary metabolism.
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Selenium
to
2
Selenium
Ascorbic acid acts as the major intracellular reducing agent to
reduce selenium to an active state for glutathione peroxidase
reduction of lipid peroxides to alcohols.
Cholesterol to Bile acids
The conversion of cholesterol to bile acids occurs with
ascorbate involved in the oxidation-reduction
processes.
Stability of C forms
Compound
Name
Reactions
L-Ascorbic acid
C1
Heat. O2, oxidized cpds, metals
L-Ascorbyl-2-sulfate
C2S
Strong acid to C1
L-Ascorgyl-2-phosphate
C2MP
Acid, base, phosphatases
L-Ascorbyl-2-triphosphate
C2-TP
Acid, base, phosphatases
L-Ascorbyl-2-glycoside
C2G
Acid, base
Dehydro Ascorbic Acid
DHC
Reduced to C1, oxidized easily
L-Ascorbyl-6-phosphate
C6P
Heat, O2, oxidized cpds
CP
Heat, O2, oxidized cpds
L-Ascorbyl-palmitate
Food stability: C2S> C2TP> C2MP> C2G> C6P> CP> DHC> C1
The stability of various forms of ascorbate vary. Many of these
compounds require enzymatic conversion to the active
ascorbic acid or C1 reduced condition.
3 Cs and a stranger
HPLC analysis of tissues indicate 3 recognized ascorbate derivatives,
and a peak lying between ascorbate-2-sulphate and ascorbate-2monophosphate.
C reduces Vibrio mortality
1 gram of C/kg feed dramatically reduces mortality from Vibrio disease in
trout.
Many Cs can cure scurvy
Salmon scurvy can be cured by feeding any of Vitamers C
Disaster at sea
Table 1
Salmon Seawater Survival
(50 day exposure test)
Hatchery site
Groups tested*
% Survival
A
6
71
B
9
54
C
6
41
D
6
21
E
6
80
F
8
90**
G
4
68
H
6
58
J
3
94***
K
3
96***
* Each group contained 200 to 300 fish
** Spring water source with hi Se and CU
*** Fed diet H440 with C, Se, and E supplements
(Source: USFWS reports Marrowstone Field Station, 1992
Salmon smolts on low Se and C diets die
when converted to sea water environment.
The DiStressed Fish 1
GTPX Rises with stress
Glutathione Peroxidase Activity (uM/mg protein)
hatchery smolts, Lower Granite Dam
13-May
5.15 + .7
19-May
16.44 + 4
hatchery smolts, Bonneville Dam
14-May
6.11 + .1
20-May
27.93 + 4
Salmon smolts confined and barged 30 hrs showed stress
and GTPX synthesis.
Microgram/gram
Tissue Selenium Loss in Hatchery Chinook After
30 Hour Barge Transport
4
3
2
1
0
1 Site
Loading
2
Discharge Site
1) Lower Granite Dam on Snake River, Washington
2) Seaward of Bonneville Dam on Columbia River
United States Army Corps Engineer Study, 2001
Dr. Halver speaking at Pecs, Hungary
Dietary Needs (mg/kg dry diet)
Se
No Deficiency
Normal Growth
0.25-0.45
1-2
7-8
Stress
C
10-15
200-300
1000
Zn
25-40
50-60
???
Stress increases the dietary needs for Se & C in GTPX, and
probably also for Cu & Zn that are involved in SOD structures.
Dr. John Emil Halver