Investigation of effects of two environmental heavy metals in a combined exposure model on the nervous system in rats

In the present study, the interaction of inhalational and oral exposure to manganese and lead was investigated. Young adult male Wistar rats (2 x 10 per group) were treated orally with MnCl2 (15 and 60 mg/kg b.w.) or Pb acetate (80 and 320 mg/kg) for 3 or 6 weeks. Then, one half of the groups was further treated by intratracheal instillation of nanoparticulate MnO2 (2.63 mg/kg) or PbO (2 mg/kg) for an equal period of time. Body weight gain and signs of general toxicity were regularly checked. Finally, the rats’ motor behavior was tested in an open field box, and their spontaneous and evoked cortical electrical activity was recorded in urethane anesthesia. MnO2 nanoparticles caused disproportionately strong reduction of body weight gain but with Pb the weight effect was more dependent on dose. In the open field test, Mn caused hypomotility, more strongly after 6 weeks oral plus 6 weeks intratracheal than after 6 weeks oral treatment. Pb-treated rats showed increased ambulation but less rearing and somewhat longer local activity. Spontaneous cortical activity was shifted to higher frequencies after oral Mn application, but this change was not intensified by subsequent nanoparticle application. Oral Pb had an opposite effect. Cortical evoked potentials showed latency lengthening. In several cases, the effect of Mn and Pb was about as strong after 3 weeks oral plus 3 weeks intratracheal as after 6 weeks oral administration, although the summed dose was ca. two times lower in the former case. There can be a more-than-additive interaction between the amounts of heavy metals entering the organism in different routes and chemical forms

Consequences of subacute intratracheal exposure of rats to cadmium oxide nanoparticles: Electrophysiological and toxicological effects

Cadmium is a metal used in various industrial applications, whereby exposure to Cd-containing fumes is likely. The submicron sized particles in the fumes represent an extra risk due to their high mobility within the organism and high surface area. Toxicity of Cd on the liver, kidney and bones is well known, but there are less data on its neurotoxicity. Here, male Wistar rats were treated for 3 and 6 weeks by intratracheal instillation of CdO2 nanosuspension. The treated rats’ body weight gain was significantly decreased, and in the high dose rats (0.4 mg/kg Cd daily) the weight of lungs and thymus was significantly increased. In this group, the spectrum of spontaneous cortical electrical activity was shifted to higher frequencies, the latency of sensory evoked potentials was lengthened, and the frequency following ability of the somatosensory evoked potential was impaired – even without detectable Cd deposition in the brain. The data support the role of the nano-sized Cd in the causation of nervous system damage and show the possibility of modeling human neurotoxic damage in rats

Subacute exposure of rats by metal oxide nanoparticles through the airways: general toxicity and neuro-functional effects

In order to create an animal model of human inhalational exposure by industrial trAct metal fumes, nanoparticulate metal oxides (MnO2 , CdO2 , PbO) were synthesized and instilled into the trachea of rats 5 times a week for 6 weeks (metal doses per kg b.w.: 2.63 and 5.26 mg Mn; 0.04 and 0.4 mg Cd; 2 and 4 mg Pb). At the end, the rats’ body weight gain during the treatment was determined, the animals had an open field session to investigate their spontaneous motility, and finally spontaneous and stimulus-evoked cortical activity was recorded in urethane anaesthesia. Mn caused decrease of open field ambulation and rearing, Cd had no effect, whereas Pb caused decreased rearing and increased ambulation. Spontaneous cortical activity was shifted to higher frequencies with each metal. Cortical evoked potentials had lengthened latency, mainly with Mn and Cd; and increased frequency dependence with Cd and Pb but hardly with Mn. The effects proved indirectly that the metal content of the nanoparticles had access form the airways to the CNS. Our method seems suitable for modelling human nervous system damage due to inhaled nanoparticles

Female Sexual Dysfunction in Association with Sexual History, Sexual Abuse and Satisfaction: A Cross-Sectional Study in Hungary

Female sexual dysfunction (FSD) has a negative impact on women’s quality of life, self-esteem, and physical health. The aim of the present study was to explore the prevalence and the factors associated with FSD using an online questionnaire. A cross-sectional survey was conducted among young adults (18−35 years old) in Hungary using the DSM-5 criteria. The participants (n = 5942) were divided into three major groups: FSD (20.3%), an intermediate group (43.9%), and a control group (35.6%). Most of the women showing FSD were affected with female orgasmic disorder (9.2%) and genito-pelvic pain/penetration disorder (4.6%), while female sexual interest/arousal disorder was found in altogether 100 women (1.7%); 4.8% of women were affected by more than one definite disorder. The occurrence of female sexual dysfunction was related to the women’s previous sexual history (first sexual experience, sexual education, early encounter with pornographic content, and sexual abuse), their self-satisfaction (with their own body, genitalia, and sexual attraction), and their sexual orientation. Sexual dysfunction showed a strong association with abuse, sexually transmitted diseases, and self-esteem. The present study identified the relationship between sexual dysfunctions and other health conditions, which can be the basis for some form of screening and early assistance programs for FSD