The antioxidant and anti-inflammatory effects of Eremina desertorum snail mucin on experimentally induced intestinal inflammation and testicular damage.

Eremina desertorum snail mucin antioxidant and anti-inflammatory effects were investigated against carbon tetrachloride (CCl4)-intestinal inflammation and testes damage. Male albino mice were intraperitoneally injected with 0.5 ml/kg b.wt of 40% CCl4, twice a week for 8 weeks. The treated groups were treated orally with mucin (after 8 weeks of CCl4 intoxication, twice a week for 4 weeks). CCl4 caused significant increases in C-reactive protein, lipid peroxidation, interleukin-2 levels and caspase-3, while decreasing the total proteins levels, activities of catalase, superoxide dismutase, and glutathione reductase contents, testosterone and 17ß estradiol levels compared with the control mice. The improvements of these parameters occurred after treatment with E. desertorum mucin, where all the biochemical measurements tended to restore to the normal values. Histopathologically, CCl4 caused ulceration in the columnar mucin secreting cells that lined the ileal mucosa, partial loss of goblet cells, abnormal villous/crypt ratio, and submucosal infiltrate of the inflammatory cells. Also, sections of testis showed alterations in the developmental spermatogenic arrangement of the same seminiferous tubules, with no spermatozoa in the center. Improvements in these architectures occurred after administration of mucin, where sections showed almost normal histological structure. In conclusion, E. desertorum mucin could be used as a supplementary material as it has antioxidant and anti-inflammatory effects; besides it has low cost.

Wound-healing activity of glycoproteins from white jade snail (Achatina fulica) on experimentally burned mice.

Burns are a global public health problem and the treatment of burn wounds is a major medical and economic issue. White jade snails (Achatina fulica) are now widely distributed in Asia, and they have been used to treat burns in folk medicine of China. In this study, the glycoproteins from white jade snails were investigated and their effect on burn healing was evaluated by a mouse burn model. The results showed that the snail mucus was mainly composed of proteins and polysaccharides, and it had good adhesion. The main component of snail mucus was glycoprotein from the results of DEAE Sepharose FF ion exchange chromatography. The 2,2-Diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging effect of 1 mg/mL snail mucus reached 13.77%. The wound healing rate of the snail mucus group was higher than that of the control group (p < 0.0001). Histopathological results showed that mice in the snail mucus group had a faster healing than that of the control group. The biochemical analysis was in agreement with the histopathological findings. These results suggested that glycoproteins from snail mucus showed effective wound healing activities in the skin of experimentally burned mice.

Responsiveness of metallothionein and hemocyanin genes to cadmium and copper exposure in the garden snail Cornu aspersum.

Terrestrial gastropods express metal-selective metallothioneins (MTs) by which they handle metal ions such as Zn2+ , Cd2+ , and Cu+ /Cu2+ through separate metabolic pathways. At the same time, they depend on the availability of sufficient amounts of Cu as an essential constituent of their respiratory protein, hemocyanin (Hc). It was, therefore, suggested that in snails Cu-dependent MT and Hc pathways might be metabolically connected. In fact, the Cu-specific snail MT (CuMT) is exclusively expressed in rhogocytes, a particular molluscan cell type present in the hemocoel and connective tissues. Snail rhogocytes are also the sites of Hc synthesis. In the present study, possible interactions between the metal-regulatory and detoxifying activity of MTs and the Cu demand of Hc isoforms was explored in the edible snail Cornu aspersum, one of the most common European helicid land snails. This species possesses CdMT and CuMT isoforms involved in metal-selective physiological tasks. In addition, C. aspersum expresses three different Hc isoforms (CaH ɑD, CaH ɑN, CaH ß). We have examined the effect of Cd2+ and Cu2+ exposure on metal accumulation in the midgut gland and mantle of C. aspersum, testing the impact of these metals on transcriptional upregulation of CdMT, CuMT, and the three Hc genes in the two organs. We found that the CuMT and CaH ɑD genes exhibit an organ-specific transcriptional upregulation in the midgut gland of Cu-exposed snails. These results are discussed in view of possible interrelationships between the metal-selective activity of snail MT isoforms and the synthesis and metabolism of Hc isoforms.

Overcoming deterrent metabolites by gaining essential nutrients: A lichen/snail case study.

Specialised metabolites in lichens are generally considered repellent compounds by consumers. Nevertheless, if the only food available is lichens rich in specialised metabolites, lichenophages must implement strategies to overcome the toxicity of these metabolites. Thus, the balance between phagostimulant nutrients and deterrent metabolites could play a key role in feeding preferences. To further understand lichen-gastropod interactions, we studied the feeding behaviour and consumption in Notodiscus hookeri, the land snail native to sub-Antarctic islands. The lichen Usnea taylorii was used because of its simple chemistry, its richness in usnic acid (specialised metabolite) and arabitol (primary metabolite) and its presence in snail habitats. Choice tests in arenas with intact lichens versus acetone-rinsed lichens were carried out to study the influence of specialised metabolites on snail behaviour and feeding preference. Simultaneously, usnic acid and arabitol were quantified and located within the lichen thallus using HPLC-DAD-MS and in situ imaging by mass spectrometry to assess whether their spatial distribution explained preferential snail grazing. No-choice feeding experiments, with the pure metabolites embedded in an artificial diet, defined a gradual gustatory response, from strong repellence (usnic acid) to high appetence (D-arabitol). This case study demonstrates that the nutritional activity of N. hookeri is governed by the chemical quality of the food and primarily by nutrient availability (arabitol), despite the presence of deterrent metabolite (usnic acid).

Selenium removal and biotransformation in a floating-leaved macrophyte system.

Selenium (Se) is an essential micronutrient for animals with a relatively narrow margin between essentiality and toxicity. To evaluate Se removal efficiency by a constructed wetland treatment system and its potential eco-risk, a floating-leaved macrophyte system was constructed, consisting of three main trophic levels. Over 21-d treatment, water Se concentration was gradually reduced by 40.40%, while 24.03% and 74.41% of the removed Se were found in the plant Nymphoides sp. and sediment, respectively. Among plant tissues, roots accumulated the highest Se level, although the greatest total Se was found in stems, followed by leaves, roots and rhizomes. X-ray absorption spectroscopy revealed that 82.65% of the absorbed selenite by the plants was biotransformed to other forms, as organo-Se species accounted for 45.38% of the Se retained in the sediment, which was primarily responsible for the entry of Se into the detritus food chain. The proportion of organo-Se compounds increased with trophic levels from sediments to fish, indicating, instead of direct uptake of selenite, the food chain transfer and biotransformation of Se may serve as a key exposure route for Se in aquatic organisms. When exposed to organo-Se compounds, i.e., SeCys and SeMet, the plants, shrimp and fish tended to accumulate more Se. However, the greater trophic transfer factor was obtained for selenate, leading to higher Se levels accumulated in fish. Overall, in addition to key mechanisms involved in Se removal, our research also provides a much better understanding of the potential eco-risk that may be posed by the floating-leaved plant system for bioremediation of Se via food chain transfer and biotransformation, paving the way for a low eco-toxic treatment system for Se remediation.

The use of natural ingredients in innovative Korean cosmeceuticals.

BACKGROUND: The cosmeceutical industry is an ever-growing and in demand market, especially in Asia. Korea has been on the forefront of creating the newest generation and most innovative cosmeceuticals products including ingredients such as snail secretions, starfish powder, botanical extracts, green tea, and red ginseng. Given their increasing prevalence in the cosmeceutical industry, scientists have been conducting investigations into these extracts and their properties. OBJECTIVE: To summarize the current literature surrounding multiple natural ingredients found in Korean cosmeceutical products. METHODS: A review of the literature surrounding natural ingredients found in Korean cosmeceuticals was conducted using PubMed (U.S. National Library of Medicine). RESULTS: Multiple natural extracts have been found to have antiaging, antitumor, and antimelanogenic effects making them useful additives in current cosmeceutical products. CONCLUSION: With the public's increasing awareness of cosmeceutical products, it is important for physicians to understand the properties of these extracts in order to inform patients correctly and ensure patient safety.

In situ assessment of phyto and zooavailability of trace elements: A complementary approach to chemical extraction procedures.

For an accurate risk assessment of sites contaminated by trace elements (TE), measurements of bioavailability must be performed. This is routinely achieved using the standardized 0.01M CaCl2 method. However, the suitability of chemical extractions as proxies of bioavailability is questionable. We analyzed the correlations between chemically estimated TE bioavailability and TE actually accumulated by coupling plant and snails bioindicators. Results showed a better correlation between plant TE contents and CaCl2 fraction while total soil concentration better explained snail TE contents. However in both cases chemical measures were not suitable to predict TE accumulation and bioavailability. Considering the soil properties only improve the estimation of Cr, Ni and Pb accumulation by plants while for snails, TE contents in viscera were dependent both on soil and plant contents and soil properties. It highlights the complementarities of biomonitoring methods to assess bioavailability. This dual approach allows a "physiologically defined" evaluation of bioavailability.

Response to phosphorus limitation varies among lake populations of the freshwater snail Potamopyrgus antipodarum.

Local adaptation--typically recognized as higher values of fitness-related traits for native vs. non-native individuals when measured in the native environment--is common in natural populations because of pervasive spatial variation in the intensity and type of natural selection. Although local adaptation has been primarily studied in the context of biotic interactions, widespread variation in abiotic characteristics of environments suggests that local adaptation in response to abiotic factors should also be common. Potamopyrgus antipodarum, a freshwater New Zealand snail that is an important model system for invasion biology and the maintenance of sexual reproduction, exhibits local adaptation to parasites and rate of water flow. As an initial step to determining whether P. antipodarum are also locally adapted to phosphorus availability, we examined whether populations differ in their responses to phosphorus limitation. We found that field-collected juvenile P. antipodarum grew at a lower rate and reached an important size threshold more slowly when fed a relatively low vs. a relatively high-phosphorus diet. We also detected significant across-population variation in individual growth rate. A marginally significant population-by-dietary phosphorus interaction along with a two-fold difference across populations in the extent of suppression of growth by low phosphorus suggests that populations of P. antipodarum may differ in their response to phosphorus limitation. Local adaptation may explain this variation, with the implication that snails from lakes with relatively low phosphorus availability should be less severely affected by phosphorus limitation than snails from lakes with higher phosphorus availability.

Apple snails and their endosymbionts bioconcentrate heavy metals and uranium from contaminated drinking water.

PURPOSE: The differential ability of apple snail tissues, endosymbionts, and eggs to bioaccumulate several metals (Sb, As, Ba, Br, Zn, Cr, Fe, Hg, Se, and U) was investigated. METHODS: Metal concentrations were determined by neutron activation analysis in several tissues, endosymbionts, and eggs from mature apple snails cultured in either drinking water or reconstituted water (prepared with American Society for Testing and Materials type I water). RESULTS: The highest bioconcentration factors (BCFs) in the midgut gland were found for Ba, Zn, Se, As, U, Br, and Hg (in decreasing order), while the highest in the kidney were for Ba, Br, and Hg. The foot showed the highest BCFs for Ba, Hg, Br, and Se (in decreasing order). Calcified tissues (uterus, shell) and eggs showed low BCFs, except for Ba. Both C corpuscles and gland tissue showed statistically higher BCFs than K corpuscles for Ba, Fe, U, Br, and Sb. The concentration of most of the studied elements was significantly lower in tissues and endosymbionts obtained from snails cultured in reconstituted water instead of drinking water. Snails cultured in reconstituted water and then exposed or not to Hg, As, and U (at the maximum contaminant level allowed by the US Environmental Protection Agency) also resulted in high levels accumulated in midgut gland, endosymbionts and kidney. CONCLUSIONS: Our findings suggest that the midgut gland (and the symbionts contained therein), the kidney, and the foot of Pomacea canaliculata may be useful bioindicators of Hg, As and U pollution in freshwater bodies and that the unrestricted use of ampullariid snails as human and animal food must be considered with caution.

[Study on liver injury of Oncomelania hupensis caused by Eomecon chinanthe sanguinarine].

OBJECTIVE: To analyze the effects of Eomecon chinanthe sanguinarine (SAN) on glucogen, enzyme activity and lipid peroxidation of Oncomelania hupensis liver so as to explore the mechanism of SAN against Oncomelania hupensis. METHODS: SAN was extracted and purified from the dry powder of Eomecon chionantha. Oncomelania hupensis were immersed in 5 mg/L sanguinarine (50 Oncomelania hupensis per 500 ml solution) or clean water at 25 degrees C for 36 h, the livers were isolated from live snails. Total glucogen content, malondialdehyde (MDA) level, activities of alanine aminotransferase (ALT), aspartate aminotransferase (AST), acid phosphatase (ACP), alkaline phosphatase (AKP), superoxide dismutase (SOD), peroxidase (POD) were determined respectively and the data were analyzed by independent t test. RESULTS: The glucogen content of snail livers in the SAN group and the control group were (12.151 +/- 0.204) and (18.113 +/- 0.163) mg/g respectively, the difference between the two groups was significant (P < 0.05); the MDA levels of the two groups were (5.298 +/- 0.441) and (4.351 +/- 0.197) nmol/mgprot respectively, and the difference was not significant (P > 0.05); the activities of ALT, AST, ACP, AKP, SOD in the SAN group were (2.760 +/- 0.076) U/mgprot, (68.723 +/- 2.295) U/mgprot, (407.949 +/-19.868) U/gprot, (191.287 +/- 0.771) U/ gprot and (48.452 +/- 0.193) U/mgprot respectively, the activities of these enzymes in the control group were (1.104 +/- 0.000) U/mgprot, (49.448 +/- 1.626) U/mgprot, (344.475 +/- 30.186) U/gprot, (121.905 +/- 3.127) U/gprot and (38.814 +/- 2.765) U/mgprot respectively, the activities of ALT, AST, ACP, AKP and SOD were significantly increased after immersed in 5 mg/L SAN for 36 h, the differences were significant (All P values < 0.05); yet the difference of POD between the SAN group [(22.170 +/- 0.018) U/mgprot] and the control group [(21.747 +/- 0.264) U/mgprot] was not significant (P > 0.05). CONCLUSION: SAN can destroy liver functions of Oncomelania hupensis through decreasing glucogen content and changing activities of some important enzymes in snail liver.

Patterning a spiralian embryo: a segregated RNA for a Tis11 ortholog is required in the 3a and 3b cells of the Ilyanassa embryo.

Spiralian embryogenesis is found in a number of animal phyla, but the molecular mechanisms that pattern these embryos remain poorly understood. A hallmark of spiralian development is the production of tiers of cells, called quartets, that share distinct developmental potentials. Many RNAs have been discovered that are segregated into particular quartets, raising the possibility that such RNAs could be involved in establishing quartet-specific developmental potentials. In the spiralian embryo of the mollusc Ilyanassa, the IoTis11 RNA is segregated into the second and third quartets, then decays in nearly all lineages except for the ventral-anterior cells of the third quartet, 3a and 3b. Previously published fate-mapping studies, extended here, show that 3a and 3b make bilaterally symmetrical contributions to the esophagus, head ectoderm, and larval musculature. Deletion of either 3a or 3b has only mild effects on development, but ablating both cells impairs development of the esophagus and several other organs. Knockdown of IoTis11 with a translation-blocking morpholino oligonucleotide causes a very similar set of phenotypes as ablation of 3a and 3b, showing that translation of this transcript is required for normal development of 3a and 3b. These results show that a segregated RNA is necessary for the cells that inherit it in a spiralian embryo. Given that RNAs are asymmetrically segregated in nearly all the early cleavages in this embryo, these results suggest that the embryo is extensively patterned by segregated factors. Our experiments also uncovered two previously unappreciated non-autonomous events during Ilyanassa development. First, we found that the embryo can regulate to develop normal esophagus after deletion of either 3a or 3b. Second, we found that the 3a or 3b lineages are required for normal development of the digestive glands, which arise from the fourth order macromeres.

Uranium exposure to the tropical duckweed Lemna aequinoctialis and pulmonate snail Amerianna cumingi: fate and toxicity.

The discharge of catchment-management water from the Ranger uranium (U) mine into Magela Creek upstream of the Ramsar-listed Magela Floodplain in Kakadu National Park is an important part of the mine's water-management system. Because U is one of the primary toxicants associated with this water, a receiving-water trigger value (TV), based on chronic toxicity data from five local native species, was derived for U. To strengthen the data set underpinning the derivation of the TV, the chronic toxicity of U to two additional tropical freshwater species, duckweed Lemna aequinoctialis (96-hour growth rate), and pulmonate gastropod, Amerianna cumingi (96-hour reproduction), was determined. The fate of U within the test systems was an important component of the study because analysis of U concentrations during the snail tests indicated that a substantial proportion of U (approximately 25%) was being lost from the test solutions when integrated during the entire test duration. Analysis of the snails and their food for U indicated that only a small proportion that was lost from solution was being taken up by the snails. Therefore, the majority of U that was lost was considered unavailable to the snails, and thus the exposure concentrations used to calculate the toxicity estimates were adjusted downward. Integrating the loss of U from the L. aequinoctialis test solutions over time showed that only a small proportion (6% to 13%) was lost during the test: Of that, almost half (2-5%) was taken up by the plants (constituting exposure). Uranium was only moderately toxic to L. aequinoctialis, with no observed-effect concentrations, lowest observed-effect concentrations, and inhibition concentrations causing 10% and 50% effects (IC10 and IC50) values of 226, 404, 207, and 1435 microg/l, respectively. A. cumingi was found to be more sensitive to U than L. aequinoctialis, with NOEC, LOEC, IC10, and IC50 values of 60, 61, 15, and 278 microg/l, respectively. The data for these two additional species will be used to revise the current TV for U in Magela Creek.

Can phosphorus limitation contribute to the maintenance of sex? A test of a key assumption.

Why sex is so common remains unclear; what is certain is that the predominance of sex despite its profound costs means that it must confer major advantages. Here, we use elemental and nucleic acid assays to evaluate a key element of a novel, integrative hypothesis considering whether sex might be favoured because of differences in body composition between sexuals and asexuals. We found that asexual Potamopyrgus antipodarum, a New Zealand snail, have markedly higher bodily phosphorus and nucleic acid content per unit mass than sexual counterparts. These differences coincide with and are almost certainly linked to the higher ploidy of the asexuals. Our results are the first documented body composition differences between sexual and asexual organisms, and the first detected phenotypic difference between sexual and asexual P. antipodarum, an important natural model system for the study of the maintenance of sex. These findings also verify a central component of our hypothesis that competition between diploid sexuals and polyploid asexuals could be influenced by phosphorus availability.

Characterizing dissolved Cu and Cd uptake in terms of the biotic ligand and biodynamics using enriched stable isotopes.

The biotic ligand model considers the biological and geochemical complexities that affect metal exposure. It relates toxicity to the fraction of physiological active sites impacted by reactive metal species. The biodynamic model is a complementary construct that predicts bioaccumulation and assumes that toxicity occurs when influx rates exceed rates of loss and detoxification. In this paper we presume that metal influx rates are mechanistically the resulting processes that characterize transmembrane transport. We use enriched stable isotopes to characterize, both in terms of the biotic ligand and biodynamics, dissolved metal uptake by a freshwater snail at water hardness varying up to 180-fold. Upon 24 h exposure, metal uptake was linear over a range encompassing most environmental concentrations; although saturation kinetics were observed at higher concentrations. Cadmium influx rates correlate with changes in the affinity of the biotic ligand, whereas those of Cu correlate with changes in both site affinity and capacity. A relationship between metal influx rate and ligand character asks whether toxicity is the result of accumulation at the biotic ligand or the rate at which metal is transported by that ligand.

Stoichiometry of consumer-driven nutrient recycling across nutrient regimes in streams.

Stoichiometric constraints within ecological interactions and their ecosystem consequences may depend on characteristics of the abiotic environment such as background nutrient levels. We assessed whether consumer identity, via differing body stoichiometry, could regulate periphyton stoichiometry across nutrient regimes in open systems. In 60 flow-through artificial streams, we factorially crossed dissolved inorganic nitrogen levels (elevated = 294 micog L(-1), ambient = 26 microg L(-1)) with dissolved inorganic phosphorus levels (DIP: elevated = 15 microg L(-1), ambient = 3 microg L(-1)) and consumer type [crayfish (body N : P = 18), snails (body N : P = 28) or a control]. At ambient DIP, periphyton in the crayfish treatment had a lower %P and a lower C : P than periphyton in the snail treatment suggesting that consumer identity, probably mediated by differing P-excretion, regulated periphyton P content. At high DIP, consumer identity no longer affected periphyton elemental composition. Therefore, the stoichiometry of consumer-driven nutrient recycling and consumer identity may be less important to ecosystem functioning in environments with elevated nutrient levels.

Toxic effect of stem bark and leaf of Euphorbia hirta plant against freshwater vector snail Lymnaea acuminata.

The aqueous stem bark and leaf extracts of plant Euphorbia hirta (family-Euphorbiaceae) have potent molluscicidal activity. Sub-lethal doses (40% and 80% of LC50) of aqueous stem bark and leaf extracts of this plant also significantly (P<0.05) alter the levels of total protein, total free amino acid, nucleic acids (DNA and RNA) and the activity of enzyme protease and acid and alkaline phosphatase in various tissues of the vector snail Lymnaea acuminata in time and dose dependent manner. Euphorbia hirta (family-Euphorbiaceae) commonly known as Dudhi, is a common medicinal plant of India, which is used in variety of diseases i.e. cough, asthma, colic, dysentery, genito urinary diseases.

Modulation of a feeding neural circuit by microinjection of K+ channel expression genes into a single identified neuron in Aplysia kurodai.

In Aplysia buccal ganglion expression genes for voltage-dependent K(+) channels (AKv1.1a) were injected into one of four electrically coupled multi-action (MA) neurons that directly inhibit jaw-closing (JC) motor neurons and may cooperatively generate their firing pattern during the feeding response. Following the DNA injection, the firing threshold increased and the spike frequency at the same current decreased in the current-induced excitation of the MA neuron; indicating a decrease in excitability of the MA neuron. This procedure also reduced the firing activity of MA neurons during the feeding-like rhythmic responses induced by the electrical nerve stimulation. Moreover, the firing pattern in JC motor neurons was remarkably changed, suggesting the effective contribution of a single MA neuron or electrically coupled MA neurons to the generation of the firing pattern in the JC motor neurons. This method appears useful for exploring the functional roles of specific neurons in complex neural circuits.

Integrated assessment of heavy metal (Pb, Zn, Cd) highway pollution: bioaccumulation in soil, Graminaceae and land snails.

To assess the contamination induced by traffic at the vicinity of a highway (A31, France), several complementary studies were carried out on two sites, with different profiles and traffic intensity. Concentrations of zinc, lead and cadmium were measured by atomic absorption spectrophotometry in deposits, roadside soil and autochthonous plants (Graminaceae) gathered at the vicinity of the highway (1-320 m), and in the viscera of snails Helix aspersa, transferred as sentinel in the sites. According to the results obtained for different compartments, the highway induces a contamination on the surrounding environment, up to 320 m, but with the maximum contamination observed between 5 and 20 m: the concentrations measured in plants at the vicinity of the highway were 2.1 mg Pb kg(-1) DW, 0.06 mg Cd kg(-1) DW, 62 mg Zn kg(-1) DW and the concentrations measured in snails were 21.3 mg Pb kg(-1) DW, 5.7 mg Cd kg(-1) DW, 510.8 mg Zn kg(-1) DW. The levels measured decreased with increasing distance from the highway. Results of the three metals studied indicated that lead seems to be the best metal to evaluate road transport contamination.

Anoxia-induced transcriptional upregulation of sarp-19: cloning and characterization of a novel EF-hand containing gene expressed in hepatopancreas of Littorina littorea.

Many marine molluscs have well-developed biochemical adaptations that allow them to live without oxygen for long periods of time, but very little is currently known about the molecular biology underlying these processes. Differential screening of a cDNA library derived from the hepatopancreas of the marine snail Littorina littorea revealed a novel anoxia-induced gene, sarp-19 (snail anoxia-responsive protein, 19 kDa). Examination of the sarp-19 transcript revealed an open reading frame that encoded a protein of 168 amino acids containing an N-terminal signal sequence and two putative EF-hand domains. Expression analysis of transcript levels established that sarp-19 accumulated over a time course of anoxia exposure, reaching a maximum 5.6-fold increase after 96 h compared with aerobic controls. However, transcript levels were reduced by 50% within 1 h when aerobic conditions were reestablished. Nuclear runoff assays confirmed transcriptional upregulation of sarp-19 during anoxia exposure, and organ explant experiments showed that the gene was also responsive to anoxia exposure in vitro. sarp-19 transcripts were also elevated in response to freezing, suggesting that the protein may have a role in the physiological responses of this intertidal snail to both aerial exposure and winter freezing. Hepatopancreas explants treated with a calcium ionophore showed increased levels of the sarp-19 transcript, suggesting a possible feedback mechanism regulated by levels of intracellular calcium. Expression was also responsive to tissue incubation with cyclic GMP and phorbol 12-myristate 13-acetate but was not affected by cyclic AMP, implicating involvement of protein kinases G and C but not protein kinase A in the expression of sarp-19. The SARP-19 protein may play a role in calcium-activated signaling during anoxia exposure in L. littorea.

Metabolic responses to dietary cholecalciferol and phosphorus in abalone Haliotis discus hannai ino.

Metabolic responses of cholecalciferol (VD(3)) and minerals (Ca, P and Mg) in abalone Haliotis discus hannai Ino to dietary VD(3) and phosphorus (P) were investigated. Based on a 2 x 2 factorial design, four casein-gelatin-based diets were formulated. The basal diet was supplemented with either 0 or 2000 IU VD(3)/kg diet and 0 or 10 g P/kg diet. The abalone was reared in P-free artificial seawater for 55 days. Results showed that dietary VD(3) was hydroxylated to 25-hydroxyvitamin D(3) [25(OH)D(3)] and 1 alpha,25-dihydroxyvitamin D(3) [1 alpha,25(OH)(2)D(3)] in abalone, and subsequently raised the serum levels of these two VD(3) metabolites. Dietary P deficiency elevated serum 1 alpha,25(OH)(2)D(3) level only when the dietary VD(3) supplementation was sufficient. The supplementations of either dietary VD(3) or P significantly increased the levels of P in serum, mantle and hepatopancreas, and only the addition of VD(3) significantly raised the concentrations of Ca in serum and mantle (P<0.05). Interaction between dietary VD(3) and P was only found significant on the concentrations of P and Mg in mantle (P<0.05). The concentrations of Ca, P and Mg in muscle were not significantly influenced by these dietary treatments. Hence, the metabolic responses in serum, muscle, mantle and hepatopancreas of abalone to dietary VD(3) and P were in different manners.