Synthesis of diene prostaglandins in freshwater fish

Bandyopadhyay, Gautam; Dutta, J.; Ghosh, Sudhamoy

doi:10.1007/bf02534663

Cited by 21 publications

(7 citation statements)

References 19 publications

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“…Conversion of AA to prostanoids in gills and other tissues has been reported in several teleost fish ( Nomura and Ogata 1976;Ogata et al 1978;Anderson et al 1981;Bandyopadhyay et al 1982, Cagen et al 1983; Srivastava and Mustafa 1984;Henderson et al 1985;Van Praag et al 1987). The high PGE 2 synthesis in rainbow trout gills reported in this study is consistent with observations on carp gills (Ogata et al 1978), eel and flounder gills (Srivastava and Mustafa 1984), and killifish gills (Van Praag et al 1987).…”

Section: Discussionsupporting

confidence: 81%

Arachidonic acid metabolism in gill homogenate and isolated gill cells from rainbow trout, Oncorhynchus mykiss: the effect of osmolality, electrolytes and prolactin

Beckman¹,

Mustafa²

1992

Fish Physiol Biochem

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An assay method based on thin layer chromatography to study the arachidonic acid (AA) metabolism in gill tissues was optimized and the effect of osmotically different incubation mediums on AA metabolism was evaluated. Rainbow trout gill tissues metabolize AA into PGE2 in highest concentration followed by PGD2, PGF2α and 6-keto-PGF1α (the stable metabolite of PGI2) among the prostanoids tested. Approximately 40% of PGE2 is synthesized within the first minute of incubation and is directly dependent on the substrate concentration (AA). As in mammalian tissues, PGE2 synthesis in fish gills is inhibited by the cyclooxygenase inhibitor indomethacin. PGE2 synthesis in gill homogenate and isolated gill cells incubated in trout Ringer was 0.45 and 1.9 ng/mg protein, respectively, and increased to 8.9 and 4.3 ng/mg protein, respectively, when incubated in KPO4 buffer, due to a ten-fold increase in the free AA. The hydroxy acid synthesis of the gill homogenate was higher (13%), and that of the isolated gill cells incubated in KPO4 buffer was lower (44%) compared to gill homogenate and cells incubated in trout Ringer. Gill homogenate incubated in 50 mM phosphate buffer with increasing sodium or potassium concentrations (up to 250 mM) exhibited a concentration-dependent increase in PGE2 synthesis (220% and 72%, respectively). Prolactin stimulated the PGE2 synthesis up to 30% while PGD2, PGF2α and 6-keto-PGF1α synthesis was not affected. This effect of prolactin was maximal when PGE2 synthesis was estimated 30 minutes after prolactin addition and diminished after two hours. These results suggest that rainbow trout gills possess the ability to metabolize AA through the cyclooxygenase and lipoxygenase pathways. PGE2 synthesis may be under the influence of ion balance and prolactin availability, indicating the probable involvement of AA metabolites in the regulation of ion balances across the gill membrane.

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Section: Discussionsupporting

confidence: 81%

Arachidonic acid metabolism in gill homogenate and isolated gill cells from rainbow trout, Oncorhynchus mykiss: the effect of osmolality, electrolytes and prolactin

Beckman¹,

Mustafa²

1992

Fish Physiol Biochem

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“…ArA and its metabolites, e.g., prostaglandin E 2 , are known to influence the hypothalamus-pituitaryinterrenal cell (HPI) axis in fish, analogous to the modulation of the mammalian hypothalamus-pituitary-adrenal (HPA) axis by prostaglandins and other eicosanoids (Gupta et al 1985;Harel et al 2001;Koven et al 2003). Tilapia (O. mossambicus) is capable of synthesizing prostaglandins from ArA via the cyclooxygenase pathway (Bandyopadhyay et al 1982), and these metabolites appear to have a dual role regulating cortisol release. The basal release of cortisol appears controlled by the cyclooxygenase metabolites of ArA, whereas the response to confinement in FW has been shown to be independent of prostaglandins Van Anholt et al 2004a).…”

Section: Discussionmentioning

confidence: 98%

The effects of arachidonic acid on the endocrine and osmoregulatory response of tilapia (Oreochromis mossambicus) acclimated to seawater and subjected to confinement stress

Anholt

Spanings

Nixon

et al. 2011

Fish Physiol Biochem

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In previous studies in freshwater tilapia (Oreochromis mossambicus), dietary supplementation with arachidonic acid (ArA; 20:4n - 6) had considerable, opposing effects on the main ion-transporting enzyme Na(+)/K(+)-ATPase in gills and kidneys and changed the release of osmoregulatory hormones, such as cortisol. The present study was performed to assess the influence of dietary ArA on (1) the osmoregulatory capacity of tilapia acclimated to seawater (SW) (34‰) and (2) the osmoregulatory imbalance associated with acute stress. The increased ambient salinity was associated with significant alterations in the tissue fatty acid composition, particularly the n - 6 polyunsaturated fatty acids (PUFAs). Tissue levels of ArA were further increased as a result of dietary supplementation, whereas docosahexaenoic acid (DHA, 22:6n - 3) and eicosapentaenoic acid (EPA, 20:5n - 3) decreased in gills and kidneys. Basal plasma cortisol as well as lactate levels were elevated in the ArA-supplemented SW-acclimated tilapia compared with the control group. The 5 min of confinement (transient stress) increased plasma cortisol, glucose, and lactate levels with significantly higher levels in ArA-supplemented tilapia. Confinement was also associated with significantly elevated plasma osmolality, sodium, chloride, and potassium levels. ArA-supplemented tilapia showed markedly lower ionic disturbances after confinement, suggesting that dietary ArA can attenuate the hydromineral imbalance associated with acute stress. These results emphasize the involvement of ArA and/or its metabolites in the endocrine and osmoregulatory processes and the response to confinement stress.

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“…For example, cultured gill cells from Atlantic salmon and rainbow trout can form the cyclooxygenase eicosanoids TXA2, 6-keto-PGFI,, PGE2, and PGD2 Beckman and Mustafa 1992), cultured killifish and Atlantic salmon gill homogenates can produce the lipoxygenase eicosanoids LTB,, LTC,, LTD,, and LTE, from AA (Praag et a1 . 1987;, and microsomes from liver, kidney, and intestinal tissues of carp, tilapia, and Asian catfish can metabolize exogenous AA to PGD,, PGE2, and PGF2, (Bandyopadhya et al 1982). In addition, thrombocytes from rainbow trout can produce TXA2 (Matsumoto et al 1989), and thrombocytes and microsomes from plaice can form TXB3 and PGE3 (Kayama et al 1986).…”

Section: Discussionmentioning

confidence: 98%

Effects of polyunsaturated fatty acids and some of their metabolites on mitotic activity of vascular smooth muscle explants from the coronary artery of rainbow trout (Oncorhynchus mykiss)

Gong¹,

Townley²,

Farrell³

1997

Can. J. Zool.

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This study is the first to examine the effects of polyunsaturated fatty acids and some of their metabolites on [3H]thymidine incorporation into vascular smooth muscle explants from the coronary artery of rainbow trout (Oncorhynchus mykiss). At a concentration of 120 pM, eicosapentaenoic acid (EPA; 20:5w3), arachidonic acid (AA; 20:4w6), and eicosatrienoic acid (ETA; 20:3w6) all approximately doubled [3H]thymidine incorporation relative to controls. At a conceqtration of 20 pM, EPA had no significant effect, while ETA inhibited and AA caused an almost 5-fold increase in ["]thymidine incorporation. The large mitogenic effect of 20 pM AA was completely inhibited by simultaneous addition of EPA to the culture medium. ETA only partially inhibited the mitogenic effect of 20 pM AA. Four AA-derived eicosanoids (or their stable analogues) were also tested. [3H]Thymidine incorporation was at least doubled with 1000 ng/mL carbacyclin (a prostacyclin analogue), 120 ng/mL prostaglandin F,,, and U-46619 (a thromboxane A, analogue), but did not reach the level of stimulation produced by 20 pM AA. Leukotriene C, had no significant effect. We conclude that dietary modulation of polyunsaturated fatty acids (PUFAs) in salmonids could have significant effects on coronary vascular smooth muscle mitosis through the incorporation of PUFAs into cell membranes and the production of eicosanoids.

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Synthesis of diene prostaglandins in freshwater fish

Cited by 21 publications

References 19 publications

Arachidonic acid metabolism in gill homogenate and isolated gill cells from rainbow trout, Oncorhynchus mykiss: the effect of osmolality, electrolytes and prolactin

Arachidonic acid metabolism in gill homogenate and isolated gill cells from rainbow trout, Oncorhynchus mykiss: the effect of osmolality, electrolytes and prolactin

The effects of arachidonic acid on the endocrine and osmoregulatory response of tilapia (Oreochromis mossambicus) acclimated to seawater and subjected to confinement stress

Effects of polyunsaturated fatty acids and some of their metabolites on mitotic activity of vascular smooth muscle explants from the coronary artery of rainbow trout (Oncorhynchus mykiss)

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