Conversion of Ascorbyl-2-Phosphate to Ascorbic Acid in Rainbow Trout.

Abstract

Conversion of L-ascorbyl-2-phosphate (ASP) to L-ascorbic acid (AsA) was investigated in vivo in rainbow trout Oncorhynchus mykiss administered with AsP orally and intraperitoneally. AsP magnesium salt or AsA (each 200ƒÊmol in 2g of casein basal diet) was orally administered to each rainbow trout once. The fish were sacrificed at varying intervals during the experimental

Intestinal Absorption and the Activity of Enzymatic Hydrolysis of Ascorbyl-2-Phosphate in Rainbow Trout.

“…It is conceivable that all the AsP transported in such a form is readily hydrolyzed to AsA in the body, because AsP has an equivalent physiologi cal activity to that of AsA 5) and the liver had a high activity of AsP hydrolysis in this investigation. The present in vitro findings support the results of our previous in vivo investigations 5,7) showing the ready conversion of AsP to AsA in the rainbow trout body. DNP is one of the uncouplers that inhibit ATP synthesis.…”

“…The HPLC conditions have been reported previously, 7) with the exception of the UV detector. The detector used was the Hitachi L-4000 UV detector, set at 254 nm.…”

Effect of dietary ascorbic acid on growth and non-specific immune responses of tiger puffer, Takifugu rubripes

“…Thus, an exogenous source of AA is required in fish diets. Many studies reported the positive effects of AA on growth performances of fish [5][6][7][8][9][10]. On the other hand, there were some contradictory reports that dietary AA did not improve the growth performance of seabream [3] and yellow croaker [11].…”

Effects of different dietary levels of L-ascorbyl-2-polyphosphate on growth and tissue vitamin C concentrations in juvenile olive flounder, Paralichthys olivaceus (Temminck et Schlegel)

“…Many reports have focused on finding more stable and bioavailable forms of AA to replace L‐ascorbic acid, which is the thermolabile, unstable vitamin C. Phosphate derivatives of AA have been shown to have antiscorbutic activity in channel catfish, Ictalurus punctatus (Rafinesque) (Wilson, Poe & Robinson 1989; El Naggar & Lovell 1991a,b); tilapia, Oreochromis niloticus (Steindachner) (Soliman, Jauncey & Roberts 1986; Shiau & Hsu 1995); rainbow trout, Oncorhynchus mykiss (Walbaum) (Miyasaki, Sato, Yoshinaka & Sakaguchi 1992; Cho & Cowey 1993); Japanese yellowtail, Seriola quinqueradiata (Temminck et Schlegel) (Kanazawa, Teshima, Koshio, Higashi & Itoh 1992); Kuman shrimp, Penaeus japonicus (Bate) (Shigueno & Itoh 1988) and grass shrimp, Penaeus monodon (Fabricius) (Shiau & Hsu 1994). Matusiewicz & Dabrowski (1995) concluded that fish (rainbow trout) have the ability to utilize ascorbic phosphate derivatives.…”