Vitamin D3-induced calcemic and phosphatemic responses in the freshwater mud eel Amphipnous cuchia maintained in different calcium environments

Abstract

Vitamin D 3 (100 ng 100 g body weight -l day -l ) was administered intraperitoneally (ip) to the freshwater mud eel Amphipnous cuchia kept in artificial freshwater, calcium-free freshwater, low-calcium freshwater (0.2 mmol/l CaCl 2 ) or calcium-rich freshwater (13.4 mmol/ l CaCl 2 ) for 15 days. Analyses of serum calcium and phosphate levels were performed on days 1, 3, 5, 10 and 15 after the beginning of the experiment (six eels from each group at each interval). Administration of vitamin D 3 elevated the serum calcium [maximum elevation occurred at day 10 in artificial freshwater (vehicle: 10.55 ± 0.298, vitamin D: 13.90 ± 0.324), low-calcium freshwater (vehicle: 11.17 ± 0.220, vitamin D: 12.98 ± 0.297) and calcium-rich freshwater (vehicle: 11.24 ± 0.373, vitamin D: 14.24 ± 0.208) whereas it occurred at day 5 (vehicle: 8.42 ± 0.253, vitamin D: 11.07 ± 0.328) in calcium-free freshwater] and phosphate levels [maximum elevation at day 15 in artificial freshwater (vehicle: 4.39 ± 0.105, vitamin D: 5.37 ± 0.121), calcium-free freshwater (vehicle: 4.25 ± 0.193, vitamin D: 5.12 ± 0.181), low-calcium freshwater (vehicle: 3.93 ± 0.199, vitamin D: 5.28 ± 0.164) and calcium-rich freshwater (vehicle: 3.77 ± 0.125, vitamin D: 5.46 ± 0.151)] of the fish maintained in the above mentioned environmental media, but the responses were more pronounced in the fish kept in calcium-rich media.

The significance of vitamin D for fish: a review

“…A similar observation was performed in freshwater mud eel ( Amphipnous cuchia ) by Srivastav (1983). Magnitude and duration of the increase of plasma calcium in response to vitamin D 3 are clearly dependent on the calcium concentration in the water (Srivastav et al 1997). If calcium is not sufficiently available from the water or from the diet, then fish can apparently supplement plasma calcium from internal sources.…”

New Perspective on the Nanoplastics Disrupting the Reproduction of an Endangered Fern in Artificial Freshwater

“…The artificial freshwater (AFW) was used as the background solution, which was prepared using deionized water with 0.06 mM KCl, 0.20 mM MgCl 2 , 0.45 mM Na 2 SO 4 , 0.8 mM CaCl 2 , and 2.10 mM NaCl. 34 The initial pH of AFW was adjusted to 7.6 using NaHCO 3 solution. The form of PS-NPs in aqueous suspension had been extensively characterized.…”