Distribution of ¹⁴C cylindrospermopsin in vivo in the mouse

Abstract

Radiolabelled 14C cylindrospermopsin (CYN) has been prepared and used to investigate the distribution and excretion of CYN in vivo in male Quackenbush mice. At a dose of 0.2 mg/kg (i.e., approx. median lethal dose) the following mean (SD) urinary and faecal recoveries (cumulative) were obtained, respectively: (0-6 hours, n = 4) 48.2 (29.3)%, 11.9 (21.4)%; (0-12 hours, n = 12) 66.0 (27.1)%, 5.7 (5.6)%; (0-24 hours, n = 12) 68.4 (26.7)%, 8.5 (8.1)%. Mean (SD) recoveries from livers at 6 hours were 20.6 (6.4)% (n = 4), at 48 hours 13.1 (7.7)% (n = 8), and 5-7 days were 2.1 (2.1)% (n = 8). A substantial amount (up to 23%) can be retained in the liver for up to 48 hours with a lesser amount retained in the kidneys. The excretion patterns show substantial interindividual variability between predominantly faecal or urinary excretion, but these patterns are not related in any simple manner to the outcome in terms of toxicity. There is at least one methanol-extractable metabolite as well as a nonmethanol-extractable metabolite in the liver. The methanol-extractable metabolite was not found in the kidney and is more hydrophilic than CYN itself on reverse phase.

Influence of Two Depuration Periods on the Activity and Transcription of Antioxidant Enzymes in Tilapia Exposed to Repeated Doses of Cylindrospermopsin under Laboratory Conditions

“…Moreover, studies of the body distribution of 14C-labeled CYN in mice have shown that the main excretory route is through the kidneys, with nearly 50% of an intraperitoneally (i.p.) administered dose appearing in the urine within 6 h, and 20% of the dose present in the liver [37]. …”

Cylindrospermopsin: A Decade of Progress on Bioaccumulation Research

“…Norris et al [97] showed CYN accumulated into the liver and kidney of mice within six hours of dosing via IP injection. The accumulation rate progressively decreased over five to seven days, after a single dosing event.…”

“…Radio-labelling of CYN would enable studies on whether the toxin can permeate all cell membranes [87]. However, only one report has been made of such a study using 14 C-labelling in mice [97]. …”

Immunohistochemical Approach to Study Cylindrospermopsin Distribution in Tilapia (Oreochromis niloticus) under Different Exposure Conditions

“…Moreover, studies of the body distribution of 14 C-labeled CYN in mice showed that CYN was mainly excreted through the kidney, as nearly 50% of an i.p. administered dose of CYN appeared in the urine in 6 h, whereas 20% of the dose was present in the liver [42]. …”