Intracellular and extracellular ion variation measurement in alpha(α)-particle irradiated cells using t-FROZEN! and laser-induced breakdown spectroscopy

Many radiobiological changes occur in unirradiated cells due to concealed signals transmitted from the irradiated cells through the Radiation-induced bystander effect (RIBE). Calcium ions (Ca2+) remain the only ion–molecule extensively studied so far amongst the ions that control cell function. This is partly due to using fluorescent indicators to investigate the signaling process that suffers limitations in labelling procedure and ion specificity. To understand the ion imbalance in irradiated cells and cell medium serving as donor and carrier of the bystander signals. Here, we investigate ion concentrations in the extracellular and intracellular space of α-particle (Am-241) irradiated Chinese hamster ovary (CHO) cells exposed to two different radiation doses (0.3 nGy, and 0.7 nGy). Laser-induced breakdown spectroscopy (LIBS) with our novel t-FROZEN! method separating the cells from its extracellular matrix was employed as a tool. Also, X-ray fluorescence spectroscopy (XRF), inductively coupled plasma-optical emission spectrometry (ICP-OES), and electrical impedance measurements were employed as complementary techniques. Our results show that influx of K+ and outflux of Na+, Mg2+, Cl- and Ca2+ occur in the irradiated cells, compared with controls, leading to an imbalance in the concentration of crucial signaling ions across the cell membrane. Our study has provided vital insights into comprehensive composition of ion-based radiation-induced bystander signals and guide the development of Na+, Mg2+, Cl- and K+ channel targeting drugs

Lithium in breast milk transiently affects the renal electrolytic balance of infants

Background: The use of lithium during breast-feeding has not been comprehensively investigated in humans due to concerns about lithium toxicity. Procedure: We analyzed lithium in the kidneys of nursed pups of lithium medicated mothers, using analytical spectroscopy in a novel rat model. The mothers were healthy rats administered lithium via gavage (1000 mg/day Li2CO3 per 50 kg body weight). Results: Lithium was detected in the breast milk, and in the blood of pups (0.08 mM), of lithium-exposed dams at post-natal day 18 (P18), during breast-feeding. No lithium was detected after breast-feeding, at P25 (4 days after cessation of nursing). The lithium pups blood had elevated urea nitrogen at P18 and reduced total T4 at P18 and P25, indicating a longer-term effect on the kidneys and the thyroid gland. Multivariate machine-learning analysis of spectroscopy data collected from the excised kidneys of pups showed elevated potassium in lithium-exposed animals both during- and after breast-feeding. The elevated renal potassium was associated with low nephrin expression in the kidneys measured immunohistochemically during breast-feeding. After lithium exposure is stopped, the filtration of lithium from the kidneys reverses these effects. Our study showed that breastfeeding during lithium use has an effect on the kidneys of the offspring in rats