RESUMO
Recent studies have shown that tactile stimulation (TS) in pups is able to prevent and/or minimize fear, anxiety behaviors, and addiction to psychostimulant drugs in adult rats. In these studies, animals have been exposed to handling from postnatal day (PND) 1-21. This study was designed to precisely establish which period of preweaning development has a greater influence of TS on neuronal development. After birth, male pups were exposed to TS from PND1-7, PND8-14, and PND15-21. In adulthood, the different periods of postnatal TS were assessed through behavioral, biochemical, and molecular assessments. Animals that received TS from PND8-14 showed lower anxiety-like symptoms, as observed by decreased anxiety index in elevated plus maze. This same TS period was able to improve rats' working memory by increasing the percentage of alternation rate in Y-maze, and induce better ability to cope with stressful situations, as showed in the defensive burying test by a reduced time of burying behavior. On the other hand, animals receiving TS in the first week of life showed longest cumulative burying time, which is directly related to increased anxiety-like behavior. Moreover, TS from PND8-14 showed lower corticosterone levels and better oxidative status, as observed by decreased lipid peroxidation and increased catalase activity in the hippocampus. Brain-derived neurotrophic factor (BDNF) immunocontent was increased in the hippocampus of animals receiving TS from PND8-14, while glucocorticoid receptors immunocontent was decreased in both TS1-7 and TS15-21 , but not TS8-14 . To the best of our knowledge, this study is the first to show TS can be more efficient if applied over a focused period of neonatal development (PND8-14) and this beneficial influence can be reflected on reduced emotionality and increased ability to address stressful situations in adulthood. © 2016 Wiley Periodicals, Inc.
Assuntos
Fator Neurotrófico Derivado do Encéfalo/metabolismo , Manobra Psicológica , Hipocampo/crescimento & desenvolvimento , Hipocampo/metabolismo , Receptores de Glucocorticoides/metabolismo , Tato , Adaptação Psicológica/fisiologia , Animais , Animais Recém-Nascidos , Ansiedade/metabolismo , Catalase/metabolismo , Corticosterona/sangue , Comportamento Exploratório/fisiologia , Peroxidação de Lipídeos/fisiologia , Masculino , Aprendizagem em Labirinto/fisiologia , Memória de Curto Prazo/fisiologia , Atividade Motora/fisiologia , Estimulação Física , Distribuição Aleatória , Ratos Wistar , Método Simples-CegoRESUMO
This study evaluated the biocompatibility of degradable polydioxanone (PDS) electrospun drug delivery systems (hereafter referred as matrices) containing metronidazole (MET) or ciprofloxacin (CIP) after subcutaneous implantation in rats. Sixty adult male rats were randomized into six groups: SHAM (sham surgery); PDS (antibiotic-free matrix); 1MET (one 25 wt% MET matrix); 1CIP (one 25 wt% CIP matrix); 2MET (two 25 wt% MET matrices); and 2CIP (two 25 wt% CIP matrices). At 3 and 30 days, animals were assessed for inflammatory cell response (ICR), collagen fibers degradation, and oxidative profile (reactive oxygen species [ROS]; lipid peroxidation [LP]; and protein carbonyl [PC]). At 3 days, percentages of no/discrete ICR were 100, 93.3, 86.7, 76.7, 50, and 66.6 for SHAM, PDS, 1MET, 1CIP, 2MET, and 2CIP, respectively. At 30 days, percentages of no/discrete ICR were 100% for SHAM, PDS, 1MET, and 1CIP and 93.3% for 2MET and 2CIP. Between 3 and 30 days, SHAM, 1CIP, and 2CIP produced collagen, while 1MET and 2MET were unchanged. At 30 days, the collagen fiber means percentages for SHAM, PDS, 1MET, 1CIP, 2MET, and 2CIP were 63.7, 60.7, 56.6, 62.6, 51.8, and 61.7, respectively. Antibiotic-eluting matrices showed similar or better oxidative behavior when compared to PDS, except for CIP-eluting matrices, which showed higher levels of PC compared to SHAM or PDS at 30 days. Collectively, our findings indicate that antibiotic-eluting matrices may be an attractive biocompatible drug delivery system to fight periodontopathogens. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part B, 2019.
Assuntos
Antibacterianos/química , Materiais Biocompatíveis/química , Ciprofloxacina/química , Metronidazol/química , Nanocápsulas/química , Nanofibras/química , Polidioxanona/química , Animais , Antibacterianos/farmacologia , Ciprofloxacina/farmacologia , Liberação Controlada de Fármacos , Humanos , Masculino , Metronidazol/farmacologia , Oxirredução , Implantação de Prótese , Ratos , Espécies Reativas de Oxigênio/metabolismo , Fatores de Tempo , Engenharia Tecidual , Alicerces TeciduaisRESUMO
The influence of trans fatty acids (TFA) on lipid profile, oxidative damage and mitochondrial function in the skin of rats exposed to ultraviolet radiation (UVR) was assessed. The first-generation offspring of female Wistar rats supplemented from pregnancy with either soybean oil (C-SO, rich in n-6 FA; control group) or hydrogenated vegetable fat (HVF, rich in TFA) were continued with the same supplements until adulthood, when half of each group was exposed to UVR for 12 weeks. The HVF group showed higher TFA cutaneous incorporation, increased protein carbonyl (PC) levels, decreased functionality of mitochondrial enzymes and antioxidant defenses of the skin. After UVR, the HVF group showed increased skin thickness and reactive species (RS) generation, with decreased skin antioxidant defenses. RS generation was positively correlated with skin thickness, wrinkles and PC levels. Once incorporated to skin, TFA make it more susceptible to developing UVR-induced disorders.