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K Dabrowski

Publications and source records attributed to K Dabrowski.

At least 37 records · Page 2Linked to original sources
PubMed1998

Body pool and synthesis of ascorbic acid in adult sea lamprey (Petromyzon marinus): an agnathan fish with gulonolactone oxidase activity.

Although many vertebrates can synthesize ascorbic acid (vitamin C), it is still unclear from the evolutionary perspective when the ability to synthesize the vitamin first appeared in the animal kingdom and how frequently the trait has been lost. We report here ascorbic acid biosynthesis ability in sea lamprey (Petromyzon marinus) which represent the most ancient vertebrate lineage examined thus far for presence of gulonolactone oxidase, the enzyme catalyzing the terminal step in biosynthesis of vitamin C. This finding supports the view that the ancestors of living vertebrates were not scurvy prone and that the loss of gulonolactone oxidase activity subsequently occurred several times in vertebrate phylogeny. Adult sea lamprey allocate significant amounts of ascorbic acid to the gonads to guaranty high-quality gametes. Tissue stores of ascorbate were maintained by de novo synthesis (1.2-1.3 mg of ascorbic acid/300-g sea lamprey per day at 15 degrees C) while sea lamprey fast during spawning migration. We estimate that the in vivo daily renewal rate of ascorbate is 4-5% of the whole-body ascorbate pool based on measurement of its biosynthesis and concentration in the whole animal.

Journal Article↗
PubMed1998

Androgenesis and homozygous gynogenesis in muskellunge (Esox masquinongy): evaluation using flow cytometry.

The purpose of this work was to study the effects of ultraviolet (UV) irradiation on denucleation of eggs and investigate the heat-shock conditions for diploidization for induction of androgenesis in muskellunge, Esox masquinongy. Several egg incubation media, including saline, Ringer's solution, and Ringer's solution supplemented with bovine serum albumin (BSA), were found suitable to maintain the egg fertility as high as in muskellunge ovarian fluid. The optimal doses of UV radiation were 660-1320 J/m2, at which 100% haploid larvae were produced at a hatching rate of 22.5 +/- 2.8%. UV irradiation at low doses (165-330 J/m2) generated abnormal larvae, which were morphologically identical to haploids. Using a flow cytometry method, it was found that cellular DNA content of these larvae was close to that of diploids but significantly lower in value and had a wider distribution (expressed as coefficient of variation) than that of control fish. This suggested that a low dose of UV irradiation might cause gene mutations, alteration of chromosomal conformation and fragmentation, but did not prevent maternal DNA from participating in mitotic division. Interference of maternal DNA residues could be another reason for the poor viability of androgenetic fish. A high dose of UV radiation (1980 J/m2) caused development of severely deformed embryos, indicating that UV radiation also damaged molecules in the eggs other than the denucleation. Our results suggest that classic color and allozyme markers might not be sufficient to prove a complete androgenesis. In order to optimize time and duration of shock for induced diploidization, we investigated the heat-shock conditions for inhibiting the first mitotic cleavage through induction of homozygous gynogenesis. We found that heat-shock treatment at 31 degrees C for 9 min starting at 1.4 tau 0 (a dimensionless factor describing progress in embryo development) after fertilization produced the highest percentage of diploids at hatching.

Animals↗
PubMed1998

Depletion of vitamin C from pig corpora lutea by prostaglandin F2 alpha-induced secretion of the vitamin.

The luteolytic effects of prostaglandin F2 alpha (PGF2 alpha) are thought to be mediated in part by the promotion of an increasingly oxidative cellular environment. Loss of antioxidants is one mechanism by which PGF2 alpha might induce or exacerbate oxidative damage within the corpus luteum. This study was performed to establish whether depletion of vitamin C is an acute effect of PGF2 alpha on the pig corpus luteum and to gain insight into the mechanism of luteal vitamin C loss at luteolysis. Gilts (n = 4) were anaesthetized and both utero-ovarian veins and an ear vein were catheterized. Each corpus luteum on the treated ovary received an intraluteal injection of PGF2 alpha (1 microgram) followed by a sustained release implant containing 100 micrograms of the prostaglandin. The other ovary served as the control and each corpus luteum received corresponding volumes of injection vehicle and blank implant. Blood was collected from the ear vein and both utero-ovarian veins every 15 min beginning 15 min before the onset of treatment. Collection of blood stopped when animals were ovariectomized and corpora lutea were collected at 2 h after treatment. Progesterone and vitamin C (ascorbate) concentrations were measured in tissue and plasma samples. PGF2 alpha-treated luteal tissue had similar progesterone, but significantly lower ascorbate, concentrations when compared with control corpora lutea. PGF2 alpha treatment resulted in a rapid and sustained increase in plasma ascorbate within the treatment-side utero-ovarian vein, while the control utero-ovarian vein and ear vein showed little change in plasma ascorbate during the experimental period. No effect of PGF2 alpha on plasma progesterone was evident. This finding suggests that PGF2 alpha depletes the pig corpus luteum of vitamin C by inducing secretion of the vitamin into the bloodstream. Further studies are necessary to determine whether the depletion of vitamin C that is induced by PGF2 alpha contributes to the demise of the pig corpus luteum.

Analysis of Variance↗
PubMed1998

Continuous of "pulse-and-withdraw" supply of ascorbic acid in the diet: a new approach to altering the bioavailability of ascorbic acid, using teleost fish as a scurvy-prone model.

In scurvy-prone animals ascorbic acid uptake is regulated by the number of intestinal "brush-border" carriers available for transport. The number of carriers is negatively affected by an increasing dietary ascorbic acid intake, thus limiting the maximum attainable uptake. We tested a new approach towards manipulating the accumulation of ascorbic acid in rainbow trout by repeatedly feeding a 10 day ascorbic acid allowance in a 1 or 3 day "pulse" followed by withdrawal, rather than spread out over the entire 10 day period. Pulse dosing led to initially increased mortalities compared to continuous dosing, but this was reversed after 55 days. Although individual weight and cumulative mortality were not significantly different after 88 days, total liver ascorbic acid levels were significantly higher in the 1-day pulse group (16.3 +/- 3.9 micrograms/g) than in the 3-day pulse (9.8 +/- 0.9 micrograms/g) or continuous (9.3 +/- 0.9 micrograms/g) groups. This led us to conclude that after an initial adaptation phase a feeding profile with intermittent ascorbic acid withdrawal results in a compensatory increase in uptake of ascorbic acid from the diet and/or a better conservation of the body pool of ascorbic acid, opening interesting new avenues for ascorbic acid dosing and therapy.

Animals↗
PubMed1997

Total ascorbate and dehydroascorbate concentrations in porcine ovarian stroma, follicles and corpora lutea throughout the estrous cycle and pregnancy.

Ovarian tissues are thought to require ascorbate as an antioxidant and enzymatic cofactor for the processes of steroid and collagen synthesis. We measured the concentrations of total ascorbate and oxidized ascorbate (dehydroascorbate, DHA) in ovarian stroma, follicles and corpora lutea (CL) throughout the estrous cycle and pregnancy of the sow. Both total ascorbate and DHA concentrations were greatest in luteal tissue and lowest in ovarian stroma across all stages examined. Within the CL, total ascorbate levels were lowest during the early, early-mid, and late luteal phase and were elevated during the mid-luteal phase. Luteal total ascorbate concentrations were further elevated during early pregnancy and were comparable to mid-luteal phase concentrations during the remainder of gestation. Luteal DHA concentrations decreased from mid to late luteal phase, and were elevated throughout pregnancy. As the CL aged during the cycle, the DHA/total ascorbate ratio decreased and remained low throughout pregnancy. Total ascorbate concentrations in follicular tissue increased during the follicular phase and were lowest during the early luteal phase. The DHA concentrations and DHA/total ascorbate ratios in follicular tissue did not differ with stage. Total ascorbate and DHA concentrations in ovarian stroma were low and did not vary with stage. We conclude that periods of maximal luteal and follicular function are associated with increased concentrations of total ascorbate within the tissue. Furthermore, luteolysis appears to be associated with depletion of luteal ascorbate species.

Journal Article↗
PubMed1996

Ascorbic acid protects against male infertility in a teleost fish.

An animal unable to synthesize ascorbic acid uniquely mimicks human and non-human primates. Therefore, in this study we used the rainbow trout, a teleost fish, as the model animal to study the importance of dietary ascorbic acid on the fertilizing ability of sperm. A high concentration of ascorbic acid in semen plays a key role in maintaining the genetic integrity of sperm cells, by preventing oxidative damage to sperm DNA. This study will show that the concentration of ascorbic acid in seminal plasma reflects the dietary intake of vitamin C. The concentration of ascorbic acid in seminal plasma of fish declined significantly in groups fed either an ascorbate-free diet (from 4.74 +/- 0.9 to 0.16 +/- 0.08 microgram ml-1) or an ascorbate-rich diet (from 37.9 +/- 4.7 to 17.7 +/- 3.2 microgram ml-1) during the spermiation season. The relationship between ascorbate status and fertility was studied in six groups of fish fed graded levels of ascorbic acid, which spermiated over a 150-day-period. Sperm from individual males was used to fertilize several batches of eggs. When the seminal plasma ascorbate concentration decreased to 7.3 microgram ml-1 a significant decrease of fertilization rate and the hatching rate of embryos resulted. This is the first evidence that dietary ascorbate level directly affected sperm quality and influenced male fertility in a scurvy-prone vertebrate.

Animals↗
PubMed1996

Characterization of acrosin-like activity of lake sturgeon (Acipenser fulvescens) spermatozoa.

Acipenserid fish sperm possess trypsin-like activity, resembling acrosin activity of mammalian sperm, which can be measured by hydrolysis of N-alpha-benzoyl-DL-arginine p-nitroanilide (BAPNA) (Ciereszko et al., 1994: J Exp Zool 268:486-491). We found that this activity can be preserved when sperm is frozen on dry ice with 0.6 M sucrose-10% dimethylsulfoxide (DMSO) extender (sperm:extender ratio 1:3), and subsequently stored in liquid nitrogen. However, other methods of freezing (without cryoprotectant at -18 degrees C, -80 degrees C, and -196 degrees C) did not protect this activity. Acrosin-like activity decreased in the course of storage of milt on ice; 88% decline was recorded after 13 days. Acrosin-like activity increased with temperature from 10 degrees C to 30 degrees C, but was inactivated at 40 degrees C to about 40% as compared to the optimum temperature. Triton X-100 inhibited activity by 15% and 72% at 0.01% and 0.1% concentrations, respectively. Activity was not affected by Mg2+ but was inhibited by Zn2+ (30% and 75% in the presence of 0.1 mM and 1 mM, respectively). Maximum velocity of substrate hydrolysis was observed at 2 mM of BAPNA. Acrosin-like activity was effectively inhibited by 4'-acetamidophenyl 4-guanidinobenzoate (AGB), an inhibitor of mammalian acrosin. Sperm acrosin-like activity correlated negatively with antiproteinase activity of seminal plasma. We conclude that sturgeon acrosin-like activity shares many properties with mammalian acrosin. On the other hand, it has some unique properties which may represent adaptations of this enzyme to the environment of external fertilization.

Acrosin↗
PubMed1996

Effect of cryopreservation and theophylline on motility characteristics of lake sturgeon (Acipenser fulvescens) spermatozoa.

Computer-assisted motility analysis (CASA) was used to evaluate the effect of cryopreservation and theophylline treatment on sperm motility of lake sturgeon (Acipenser fulvescens ). Motility was recorded at 0 and 5 min postactivation. The effect of cryopreservation on sperm acrosin-like activity was also measured. Cryopreservation led to a decline in the percentage of motile spermatozoa, while other parameters of sperm motion, curvilinear and straight line velocities, linearity and amplitude of lateral head displacement were unchanged. Reductions in straight line velocity observed with fresh and cryopreserved spermatozoa and in linearity with cryopreserved spermatozoa 5 min postactivation were not seen in the presence of 5 mM theophylline at this time point. Frozen-thawed spermatozoa retained acrosin-like activity, and it correlated with the percentage of post-thaw motility (r = 0.95 and r = 0.90, P < 0.05, for 0 and 5 min post-activation time, respectively).

Journal Article↗
PubMed1996

Utilization of the bone/liver alkaline phosphatase activity ratio in blood plasma as an indicator of ascorbate deficiency in salmonid fish.

The goal of this study was to test the hypothesis that the ratio of liver to bone alkaline phosphatase in blood plasma reflects the ascorbate status in scurvy-prone teleost fish (rainbow trout [Oncorhynchus mykiss]). The studies focused on finding a method for distinguishing bone alkaline phosphatase present in blood plasma from other alkaline phosphatase isoforms. We tested temperature optima and thermostability of liver, kidney, gill cartilage, and intestinal alkaline phosphatases. We did not observe differences among liver, bone, and kidney enzymes with respect to temperature optima and thermostability. We partially purified alkaline phosphatase from juvenile rainbow trout vertebrae and liver using n-butanol solubilization and ammonium sulfate fractionation. We found a difference between bone alkaline phosphatase, which precipitated in 0%-20% ammonium sulfate saturation, and liver enzyme, which required 40%-50% ammonium sulfate saturation to precipitation. We conducted a series of urea inactivation studies on partially purified enzymes from liver and vertebrae. Urea differentially inhibited the enzymes with t 1/2 = 1.1 and 0.4 min, for bone and liver, respectively. Subsequently, we subjected blood plasma alkaline phosphatase to urea inhibition, and using regression analysis we calculated the ratio of liver to bone alkaline phosphatase. We found that thus obtained ratios of bone enzyme in blood plasma correlated with liver ascorbate concentration. Bone alkaline phosphatase declined in ascorbate deficiency 10-fold, whereas low ascorbate status resulted in a 3.5-fold decrease. In order to draw a general conclusion on the linearity of the response of blood plasma/bone alkaline phosphatase as an indicator of ascorbate deficiency in fish, further studies must include analysis of individual fish followed in the process of developing avitaminosis.

Alkaline Phosphatase↗
PubMed1995

Protective effect of seminal plasma proteins on the degradation of ascorbic acid.

The objectives of this study were to determine ascorbic acid stability and its effect on antiproteinase activity of seminal plasma in the presence of an oxidant. Effect of seminal plasma, and additives: glutathione, albumin, hydrogen peroxide and Tris buffer, on ascorbic acid degradation was investigated by UV absorbance. Antiproteinase against trypsin amidase activity was measured spectrophotometrically using N-benzoyl-DL-arginine-p-nitroanilide (BAPNA) as substrate. Ascorbic acid was destroyed much more rapidly with the addition of hydrogen peroxide than in Tris buffer at pH 8.2 alone. Seminal plasma protected ascorbic acid more efficiently than glutathione and albumin alone. The protective effect of seminal plasma on ascorbic acid degradation may closely relate to the function of ascorbic acid in reproductive system of scurvy-prone animals including teleost fish. Within the range of 1-8 mM concentrations, ascorbic acid had a pro-oxidant action on seminal plasma antiproteinase activity in vitro when they were incubated with hydrogen peroxide.

Animals↗
PubMed1995

Ascorbate polyphosphate is a bioavailable vitamin C source in juvenile rainbow trout: tissue saturation and compartmentalization model.

We studied the bioavailability of ascorbic acid ester, ascorbate polyphosphate, to juvenile rainbow trout (Oncorhynchus mykiss). Fish were fed molar equivalents of 0, 20, 40, 80, 160, 320 and 1280 mg ascorbic acid/kg diet in the form of ascorbate polyphosphate. During the 18 wk of the experiment, when body weight increase averaged 3.5-fold, we did not observe any deficiency symptoms in any group. Liver and kidney ascorbate concentrations differed significantly among groups after wk 9. The ascorbic acid concentrations in liver were significantly different in fish fed for 9 wk an equivalent of 0, 40 and 160 mg ascorbic acid/kg as ascorbate polyphosphate, values were 22.7 +/- 3.4, 93.7 +/- 17.0 and 368.0 +/- 60.8 nmol ascorbic acid/g. The ascorbic acid concentrations in kidney were significantly different in fish fed for 18 wk an equivalent of 0,20 and 40 mg ascorbic acid/kg as ascorbic polyphosphate (23.9 +/- 4.0, 72.1 +/- 13.6 and 254.4 +/- 22.7 nmol ascorbic acid/g, respectively). After wk 18, fish from groups fed 0, 20, 320 and 1280 mg ascorbic polyphosphate/kg were intraperitoneally injected with 25 mg/ascorbic acid/kg body wt. We observed differences in the profiles of tissue ascorbate concentration during the 96 h following the injection between groups with high and low tissue ascorbate concentration, i.e., fish fed 320 and 0 ascorbic acid/kg, respectively. We conclude that ascorbic acid metabolism in rainbow trout after intraperitoneal injection followed the three-compartmental model, with the intraperitoneal cavity as the first compartment, blood as the second, and tissues as the third.(ABSTRACT TRUNCATED AT 250 WORDS)

Aging↗
PubMed1995

Reproductive success of female rainbow trout (Oncorhynchus mykiss) in response to graded dietary ascorbyl monophosphate levels.

Ascorbic acid is an essential nutrient in rainbow trout diets and has been shown to play an important role in fish reproduction. Recommended dietary levels are based on immature fish, and the specific requirements for brood stock are unknown. To establish the optimum dietary level for mature rainbow trout, six graded levels of ascorbyl-2-monophosphate were fed to groups of female fish over a period of 10 mo until spawning. Increasing dietary levels of ascorbyl monophosphate resulted in significantly increased ascorbic acid concentrations in liver, kidney, ovaries, and ovulated eggs. Liver and egg concentrations were saturable at 109.3 and 266.6 micrograms ascorbic acid/g tissue, respectively. Tissue saturation levels of 83.7% and 91.2%, respectively, were reached at the highest dietary level (870 mg ascorbyl monophosphate/kg diet) tested. Both fecundity and embryo survival increased significantly with dietary ascorbyl monophosphate levels. The results indicated that the present National Research Council recommended dietary level of 50 mg ascorbic acid/kg diet for rainbow trout is inadequate for brood stock fish. An amount 8 times higher is necessary to optimize tissue ascorbic acid levels and achieve maximum reproductive success.

Animals↗
PubMed1995

Sperm quality and ascorbic acid concentration in rainbow trout semen are affected by dietary vitamin C: an across-season study.

High concentrations of ascorbic acid occur in scurvy-prone, teleost fish plasma. We quantified seasonal relationships between 1) dietary level of vitamin C and level of seminal plasma ascorbic acid, and 2) seminal plasma ascorbic acid concentration and sperm quality, in rainbow trout (Oncorhynchus mykiss). We maintained six groups of 2-yr-old rainbow trout on diets supplemented with 0, 30, 110, 220, 440, and 870 ppm ascorbyl monophosphate beginning in May 1992. Sperm were produced during the end of October 1992 through April 1993; we collected milt 13 times from 3-8 fish per treatment. We quantified ascorbic acid concentration in seminal plasma, and sperm concentration, motility, and weight. Seminal plasma ascorbic acid concentrations were affected directly by the ascorbyl monophosphate level in the diet. Seminal plasma ascorbic acid concentrations also were affected by season. Ascorbic acid deficiency did not influence semen quality (sperm concentration and motility) at the beginning of the spawning season. However, sperm concentration and motility in a group fed an ascorbic acid-free diet declined during the period of study. Ascorbic acid deficiency reduced both sperm concentration and motility, and thus fertility, of rainbow trout. These results indicate that vitamin C is important for male fish reproduction; the dietary requirement for seminal plasma ascorbic acid saturation exceeds that for optimum growth.

Animals↗
PubMed1994

Efficacy of magnesium-L-ascorbyl-2-phosphate as a vitamin C source for weanling and growing-finishing swine.

Two experiments were conducted, one with weanling pigs (n = 288) and the second with grower-finisher swine (n = 216), to evaluate the efficacy of dietary vitamin C on various performance and serum measurements. Magnesium-L-ascorbyl-2-phosphate (46% L-ascorbic acid) served as the vitamin C source and was incorporated at dietary levels of 0, 50, or 500 ppm in both experiments. Pigs were allotted by sex, weight, and litter to randomized complete block designs. The nursery trial was conducted at four time periods and contained 12 replicates, whereas the grower-finisher experiment was over four time periods and contained nine replicates. Blood samples were collected initially from nine randomly selected pigs in both experiments, and from each pig within each pen at 2 and 5 wk postweaning, and at the 4- and 8-wk period in the grower-finisher trial. A killed Salmonella typhinurium bacterin was injected i.m. into starter pigs at 2 wk postweaning and at wk 4 and 6 in grower-finisher pigs. Hemagglutination titers were evaluated at 5 wk with the nursery pigs and at the 8-wk period with the grower-finisher swine. At the end of the grower-finisher trial, liver and kidney tissue were analyzed for ascorbate. Starter pigs grew faster (P < .05) and had improved gain:feed ratios (P < .05) when vitamin C was provided during the first 2 wk postweaning, but not during the latter 3-wk period. There was no improvement in pig gain or feed efficiency to vitamin C supplementation during any phase of the grower-finisher period.(ABSTRACT TRUNCATED AT 250 WORDS)

Animal Feed↗
PubMed1993

Ascorbate-2-sulfate sulfohydrolase in fish and mammal. Comparative characterization and possible involvement in ascorbate metabolism.

1. The new assay conditions were determined for crude and purified enzyme ascorbate-2-sulfate sulfohydrolase from liver tissues of two fish species and bovine. 2. The major departure from the existing indirect method, based on reduction of 2,6-dichlorophenolindophenol (DCIP) by released ascorbic acid and change from pink-blue to a colorless molecule, takes into account the shift of maximum absorbance of DCIP from 516 nm at pH 5.14 to 600 nm at pH 6.5. 3. The direct method is based on colorimetric assay of liberated ascorbic acid including correction for interfering substances. The optimum pH for both fish ascorbate sulfatases was 5.5. 4. The Km for bovine ascorbate sulfatase was confirmed to be approximately 7 mM at 37 degrees C. 5. Partly purified ascorbate-sulfate sulfohydrolase has a Km value in rainbow trout of 0.4 mM and it changes very little in the range of water temperatures characteristic for this stenothermic fish species. 6. In eurythermic chub, the Km values increased from 1.2 to 4.3 mM with rising temperatures.

2,6-Dichloroindophenol↗
PubMed1991

The effect of large doses of vitamin C and magnesium on stress responses in common carp, Cyprinus carpio.

1. Plasma magnesium, cortisol, lactate and ascorbic acid were examined in common carp subjected to various dietary treatments and following handling stress. 2. Under conditions of satisfied dietary magnesium and ascorbate requirements, plasma cortisol concentration after stress increased less pronouncedly than in fish fed large doses of ascorbate and/or magnesium. 3. Plasma lactate increased significantly in all groups after stress, although the increase seemed to be more severe (detrimental) in fish on large doses of ascorbate, either as ascorbic acid (AA) or ascorbic monophosphate Mg salt (AP). 4. Large doses of dietary ascorbate, both AA and AP, resulted in a significant increase of total ascorbate concentration in kidney and hepatopancreas of carp in comparison to pre-experimental level. 5. Kidney total ascorbate concentration decreased by 10-23% in all groups but one in which fish fed diet supplemented with AA displayed a significant increase (30%) of tissue ascorbate. The opposite trend was found in hepatopancreas of AA group with 21.5% ascorbate depletion. 6. The present results suggest that plasma cortisol and kidney (steroidogenesis site) and hepatopancreas ascorbate concentration responses to stress may not be related. Our results also do not support the hypothesis of the primary role of the high concentration of ascorbate in the kidney inhibiting steroidogenesis.

Animals↗
PubMed1990

Absorption of ascorbic acid and ascorbic sulfate and ascorbate metabolism in common carp (Cyprinus carpio L.).

Ascorbate metabolism was analyzed in fasted common carp and carp offered diets lacking ascorbic acid or supplemented with ascorbic acid (AA) or ascorbic sulfate (AS). Ascorbic acid and ascorbic sulfate were analyzed in the contents collected from various parts of the digestive tract. The major site of the dietary ascorbate absorption was located in the first 20% of the anterior intestine region (58.7 +/- 10.2%), whereas absorption increased to 94.3 +/- 1.9% (in the whole gut). Considerable secretion of ascorbate into the initial part of the intestine was found (71 micrograms AA.g-1 dry food) in fish offered the diet lacking ascorbate, but this amount was completely reabsorbed in the following portions of the intestine. AS was concentrated in the contents of the digestive tract and the external marker method revealed no absorption of AS from the intestine. In fish fed the AA-supplemented diet, the concentration of ascorbate in plasma, hepatopancreas, kidney, intestine, spleen, and brain was significantly (P less than 0.01) higher than in similar tissues from the other groups, suggesting that ascorbic sulfate hydrolysis was ineffective. Small amounts of AS were found in the intestine and spleen of fish fed a diet supplemented with AS. Ascorbate analysis in the whole fish allowed the estimate of the catabolic rate of fasting and scorbutic-diet-fed fish, which amounted to 0.7% and 1.46% daily of the ascorbate body pool, respectively. There was no indication that ascorbic sulfate sulfohydrolase activity was induced in hepatic, kidney, or intestinal tissue of fish offered a diet with AS in comparison to other groups. It seems unlikely that cyprinid fish are able to utilize ascorbic sulfate as a vitamin C source, and thus resemble scurvy-prone mammals in this respect.

Animals↗