Premium
Zinc (Zn) accumulation and metallothionein (MT‐1) expression in choroid plexus of spiny dogfish shark (S. acanthias)
Author(s) -
Villalobos Alice R,
Perry Deborah,
Taylor Robert J,
Young Robin K
Publication year - 2011
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.25.1_supplement.lb527
Subject(s) - metallothionein , chemistry , extracellular , zinc , intracellular , choroid plexus , gene expression , spiny dogfish , microbiology and biotechnology , biochemistry , endocrinology , gene , biology , squalus acanthias , organic chemistry , central nervous system
Our objective is to determine whether Zn deficiency elicits changes in Zn accumulation and expression of the Zn‐binding protein, MT‐1 in isolated CP of spiny dogfish shark. Endogenous Zn in lateral CP, IVth CP, plasma and CSF from 5 sharks was analyzed by inductively coupled plasma mass spectrometry (ICP‐MS) and expressed in parts per million (ppm) of tissue wet weight (± 0.1 mg). Zn concentrations (mean ppm ± SE) were 0.22 ± 0.06 and 0.18 ± 0.02 in plasma and CSF but 14.16 ± 0.06 and 10.92 ± 1.78 in lateral CP and IVth CP. Zn accumulation and MT‐1 expression were examined in isolated lateral and IVth CP incubated with 0 or 10 μM ZnCl 2 in elasmobranch L‐15 medium for 24 h. As per ICP‐MS, total Zn was 20 ppm in Zn‐treated CP and 9 ppm in control CP. As per real‐time RT‐PCR, MT‐1 gene expression in Zn‐treated CP was 425‐fold greater than that in control. Separate tissues were incubated with 10 μM Zn or a Zn chelator N,N,N′,N′,‐tetrakis‐2 pyridylmethyl‐ethylenediamine (TPEN, 2 μM) for 24 h. TPEN did not alter total Zn accumulation but suppressed MT‐1 gene expression by 80%. These data suggest that as extracellular Zn increases, CP accumulates additional Zn, but up‐regulation of MT‐1 may serve to bind Zn and regulate intracellular free concentrations. However, despite Zn depletion total intracellular Zn is not markedly decreased; however, decreased MT‐1 expression may in affect increase intracellular Zn availability.