Sharma, HS; Kiyatkin, EA; Patnaik, R; Lafuente, JV; Muresanu, DF; Sjöquist, PO; Sharma, A
In this study, we examined the influence of cold and hot environments on methamphetamine (METH) neurotoxicity in both drug-naive rats and animals previously exposed to different types of nanoparticles (NPs). Since METH induces oxidative stress, we also examined how a potential chain-breaking antioxidant H-290/51 (Astra-Zeneca, Mölndal, Sweden) affects METH-induced neurotoxicity. Exposure of drug-naive rats to METH (9 mg/kg, s.c.) at 4, 21, or 34 °C for 3 h resulted in breakdown of the blood-brain barrier (BBB), brain edema, and neuronal injuries, which all differed in severity depending upon ambient temperatures. The changes were moderate at 21 °C, 120-180 % larger at 34 °C, and almost absent at 4 °C. In rats chronically treated with NPs (SiO2, Cu, or Ag; 50-60 nm, 50 mg/kg, i.p. for 7 days), METH-induced brain alterations showed a two- to fourfold increase at 21 °C, a four- to sixfold increase at 34 °C, and three- to fourfold increase at 4 °C. SiO2 exposure showed the most pronounced METH-induced brain pathology at all temperatures followed by Ag and Cu NPs. Pretreatment with a potent antioxidant compound H-290/51 (50 mg/kg, p.o., 30 min before METH) significantly reduced brain pathology in naive animals exposed to METH at 21 and 34 °C. In NPs-treated animals, however, attenuation of METH-induced brain pathology occurred only after repeated exposure of H-290/51 (-30 min, 0 min, and +30 min). These observations are the first to show that NPs exacerbate METH-induced brain pathology in both cold and hot environments and demonstrate that timely intervention with antioxidant H-290/51 could have neuroprotective effects.
; Animals; Antioxidants/pharmacology; Antioxidants/therapeutic use; Astrocytes/drug effects; Blood-Brain Barrier/drug effects; Body Temperature; Brain/drug effects; Brain/pathology; Brain Edema/chemically induced; Brain Edema/pathology; Cold Temperature/adverse effects; Coloring Agents/pharmacokinetics; Copper/toxicity; Drug Synergism; Evans Blue/pharmacokinetics; Hemodynamics/drug effects; Hot Temperature/adverse effects; Indoles/pharmacology; Indoles/therapeutic use; Male; Methamphetamine/toxicity; Nanoparticles/toxicity; Neurons/drug effects; Neurons/ultrastructure; Neuroprotective Agents/pharmacology; Neuroprotective Agents/therapeutic use; Permeability/drug effects; Rats; Rats; Sprague-Dawley; Silicon Dioxide/toxicity; Silver/toxicity; Skin Temperature; Index Medicus/
