Copper, zinc, phosphorus and sulfur distribution in thin section of rat brain tissues measured by laser ablation inductively coupled plasma mass spectrometry: possibility for small-size tumor analysis

Abstract

A microanalytical method using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) was developed to measure element distribution in rat brain tissues for the detection of a small-size tumor. The stereotaxically guided tumor was implanted by injecting 5 ml of 10 3 F98 cells into the right Caudatus putamen of a male F344 Fisher rat brain hemisphere. The second non-treated rat brain hemisphere is used as control tissue. Tumor investigation of adjacent slices is carried out by LA-ICP-MS and, in addition, autoradiographically with a tritiated ligand (3 H-PK11195) of the peripheral benzodiazepine-receptor, which is not expressed in the brain under normal, physiological conditions but during tumor development. Ion intensities of 63 Cu 1 , 64 Zn 1 , 31 P 1 and 32 S 1 in the rat brain section (thickness: 20 mm; analyzed area 12 mm by 6 mm) containing the local tumor and control area were measured by scanning with a focused laser beam at wavelength 213 nm, diameter of laser crater 50 mm and laser power density 3 Á 10 9 W cm À2 , in a cooled laser ablation chamber coupled to a double-focusing sector field ICP-MS. The quantitative determination of element distribution in a thin slice of the rat brain tissue was carried out using matrix-matched laboratory standards. The mass spectrometric analysis yielded an inhomogeneous distribution for Cu, Zn, S and P in the analyzed rat brain sections. For Cu and Zn a deficiency in and around the tumor region in comparison with the control brain tissue of the second hemisphere was found. The detection limits for distribution analysis of Zn and Cu measured by LA-ICP-MS are in the ng g À1 range. The capability and the limits of LA-ICP-MS will be studied for the imaging of element distribution in thin cross sections of brain tissues in order to create a new diagnostic method for the borders of small-size tumors.

Laser bidezko ablazioaren egungo egoera eta aplikazioak

“…Tumoreek energia-eskakizun eta glikolisi-tasa handia dute [64]. Hortaz, elementu ez-metaliko horren banaketa irudikatzea lagungarria izan daiteke tamaina txikiko tumoreen diagnostiko-erreminta gisa.…”

Inductively coupled plasma- and glow discharge plasma-sector field mass spectrometry : Part II. Applications

“…41 Element distributions in rat and human brain tissue sections have been investigated by LA-ICP-SFMS. 42,43 Pb showed a more or less homogeneous distribution in human brain whereas Zn and Cu were found in higher concentrations in the hippocampus. Laser ablation ICP-SFMS was used for the determination and spatial elemental profiling of Ni concentrations in tissues that had been exposed to nickel wire.…”

A calibration strategy for LA-ICP-MS using isotope dilution for solid reference materials

“…A disadvantage of this method is the timeconsuming and complex preparation of calibration standards at several different concentration levels. 25 The preparation of matrix-matched standards is also very time consuming and complex [26][27][28][29][30] and must be especially adaptable to biological samples. In addition to these problems the homogeneity of matrix-matched standards is oen insufficient, which decreases the accuracy.…”