RESUMO
PURPOSE OF THE STUDY: The prevalence of vitamin D deficiency in pediatric populations is high. In the present study we analyzed associations between vitamin D therapy and pain, mobility, fatigue, and daily functioning in children with musculoskeletal/orthopedic conditions suffering from chronic and recurrent pain, but also diagnosed with vitamin D deficiency. MATERIAL AND METHODS: Children with different musculoskeletal/orthopedic conditions and vitamin D deficiency were prescribed to receive vitamin D over 6 months. Thirty-five children (18 males; age 10.48 ± 3.87 years) completed a 6-month follow-up. Self- and parent/proxy rating scales were used to evaluate pain, movement, fatigue, and daily functioning. RESULTS: At a six-month follow-up assessment involving child- and parent-reported scores, worst pain intensity significantly decreased (p ≤ 0.03) after vitamin D therapy, as well as functioning problems related to pain (p ≤ 0.01). The children reported better movement and balance with less fatigue. The parents reported better functioning in everyday activities of their children. CONCLUSION: This pilot study showed that vitamin D therapy possibly reduces pain intensity and improves mobility and daily functioning in children with musculoskeletal/orthopedic disorders, chronic recurrent pain, and vitamin D deficiency. Further follow-up and randomized studies are required in order to assess the validity of clinical recommendations.
Assuntos
Dor Musculoesquelética/diagnóstico , Dor Musculoesquelética/tratamento farmacológico , Medição da Dor/efeitos dos fármacos , Deficiência de Vitamina D/diagnóstico , Deficiência de Vitamina D/tratamento farmacológico , Vitamina D/uso terapêutico , Adolescente , Criança , Fadiga/tratamento farmacológico , Feminino , Seguimentos , Humanos , Masculino , Doenças Musculoesqueléticas/diagnóstico , Doenças Musculoesqueléticas/tratamento farmacológico , Dor Musculoesquelética/sangue , Projetos Piloto , Prevalência , Vitamina D/análogos & derivados , Vitamina D/sangue , Deficiência de Vitamina D/sangueRESUMO
Rhabdomyosarcoma (RMS) is a highly malignant cancer. Over the last two decades, prognosis for RMS patients has significantly improved, with the exception of those in the high-risk group. In order to identify new prognostic factors, we investigated the expression of nestin in RMS cells and its correlation with clinicopathological features and patient outcome. The analysis of overall survival for all patients (N = 30) revealed 1-, 2-, 3-, 4-, and 5-year survival rates of 93.3, 83.3, 66.7, 63.3, and 63.3%, respectively. Nestin overexpression significantly correlated with survival (P = 0.044). Survival of patients with ≤ 50% nestin-positive cells was 90, 70, and 40% after 1, 2, and 3 years, respectively, and remained unchanged until the end of the investigation period. The study group composed of patients exhibiting nestin expression in >50% of cells showed 1-, 2-, 3-, and 4-year survival rates of 95, 90, 80, and 75%, respectively, remaining stable at 75% for the fifth year of observation. A nestin-positive expression rate lower than 50% was observed more frequently in older patients (43.60 ± 27.58 years; P = 0.028). In addition, higher rates of nestin expression were observed in most embryonal RMS specimens and low-grade tumors, in early stages of the disease, and among younger patients. Our results lead us to propose nestin as possible positive prognostic factor in RMS.
Assuntos
Biomarcadores Tumorais/biossíntese , Nestina/biossíntese , Prognóstico , Rabdomiossarcoma/genética , Adolescente , Adulto , Idoso , Biomarcadores Tumorais/genética , Criança , Pré-Escolar , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Nestina/genética , Rabdomiossarcoma/patologiaRESUMO
We have found that the metabolism of 5-hydroxytryptamine increases in the hippocampus and that the metabolism of dopamine decreases in the striatum and thalamus during slow-wave sleep, and we suggest that these changes are related to this stage of sleep. We have also found that the concentration of dopamine increases in the hippocampus during slow-wave sleep, and suggest that this may be related to the subsequent appearance of paradoxical sleep. These data raise new questions on the hippocampal role in the sleep-wakefulness cycle.
Assuntos
Encéfalo/metabolismo , Dopamina/metabolismo , Serotonina/metabolismo , Fases do Sono/fisiologia , Animais , Gatos , Núcleo Caudado/metabolismo , Córtex Cerebral/metabolismo , Corpo Estriado/metabolismo , Hipocampo/metabolismo , Ácido Homovanílico/metabolismo , Ácido Hidroxi-Indolacético/metabolismo , Norepinefrina/metabolismo , Tálamo/metabolismoRESUMO
In this study we compared the effects of PCB126 and PCB153 on adult rat testicular androgenesis and the status of antioxidant enzymes in the interstitial cell compartment 96h after local intratesticular application. Obtained results indicated PCB126-induced inhibition of conversion of progesterone (P) and Δ(4)-androstenedione (A(4)) to testosterone (T), and stimulation of conversion of P to T induced by PCB153, while combined application had no effect. Activities of antioxidant enzymes were unchanged, except of decreased activity of SOD in PCB126-treated group. In parallel experiments, adult purified Leydig cells challenged with PCB congeners were incubated for 2h in the presence of corresponding steroid substrates. Results demonstrated that in the presence of subsaturating substrate concentrations PCB126 induced inhibition of conversion of P and A(4) to T at nM to µM doses, while PCB153 caused stimulation at nM concentrations. Further studies should indicate possible mechanism(s) of modulation of androgenesis by tested PCB congeners.
RESUMO
The immobilization stress induces an acute inhibition of testicular steroidogenesis that is mediated by the nitric oxide (NO) signaling pathway. Here we compared the effects of 2-h immobilization stress on in vivo and in vitro rat steroidogenesis at two time points, 0 h and 6 h after the end of the stress session. As expected, serum androgens and human chorionic gonadotropin (hCG)-stimulated progesterone and testosterone production by testicular tissue were inhibited at 0 h, and also at the 6-h time point. Both the acute and sustained inhibitions of in vitro steroidogenesis were accompanied by a significant increase in nitrite, a stable oxidation product of NO. To clarify which subtype of NO synthase (NOS) (constitutive (cNOS) or inducible (iNOS)) participates in down-regulation of testicular steroidogenesis, aminoguanidine hydrochloride (AG), a selective iNOS inhibitor, was employed. Intratesticular injection of AG prevented the sustained, but not the acute, stress-induced decrease in serum testosterone. When added in vitro, it also prevented the sustained decrease in steroid production and increase in nitrite production by testicular tissue, both in a dose-dependent manner and with EC microM. Furthermore, AG added in vivo and in vitro effectively blocked the sustained decrease in 3beta-hydroxysteroid dehydrogenase (3betaHSD) and 17alpha-hydroxylase/C17-20 lyase (P450c17) activities. In all concentrations employed, AG did not affect serum androgens and in vitro steroid and nitrite production in unstressed animals. These results indicate that the NO signaling pathway participates in acute and sustained stress-induced down-regulation of testicular steroidogenesis, presumably through its direct action on 3betaHSD and P450c17. The acute NO production is controlled by cNOS and the sustained production of this messenger is controlled by iNOS.
Assuntos
Óxido Nítrico Sintase/metabolismo , Transdução de Sinais , Estresse Psicológico/metabolismo , Testículo/efeitos dos fármacos , Testosterona/metabolismo , Animais , Di-Hidrotestosterona/metabolismo , Inibidores Enzimáticos/farmacologia , Guanidinas/farmacologia , Masculino , Óxido Nítrico Sintase/antagonistas & inibidores , Óxido Nítrico Sintase Tipo II , Óxido Nítrico Sintase Tipo III , Nitritos/metabolismo , Progesterona/metabolismo , Ratos , Ratos Wistar , Restrição Física , Estatísticas não Paramétricas , Testículo/metabolismo , Fatores de TempoRESUMO
Polychlorinated biphenyl (PCB)-based transformer fluids belong to a class of environmentally persistent mixtures with known toxic effects. Here, we studied the acute effects of Askarel (which contains Aroclor 1260) and two substitute transformer fluids (the silicone oil-based DC561 and the mineral oil-based ENOL C) on rat testicular steroidogenesis. Single intraperitoneal (ip; 10 mg/kg body weight) or bilateral intratesticular (itt; 25 microg/testis) injections of Askarel markedly decreased serum androgen levels 24 hr after administration. In acute testicular cultures from these animals, chorionic gonadotropin-stimulated progesterone and androgen productions were severely attenuated. When itt was injected or added in vitro, Askarel inhibited 3ss-hydroxysteroid dehydrogenase (3ssHSD), stimulated 17[alpha]-hydroxylase/lyase (P450c17), and did not affect 17ss-hydroxysteroid dehydrogenase in testicular postmitochondrial fractions. The ip-injected Askarel did not affect 3ssHSD, but inhibited P450c17, suggesting that a more intensive metabolism of peripherally injected Askarel reduces the circulating levels of active ingredients below the threshold needed for inhibition of 3ssHSD and generates a derivative that inhibits P450c17. In contrast to Askarel, itt-injection (25 microg/testis) of DC561 and ENOL C did not affect in vivo and in vitro steroidogenesis. These findings show the acute effects of Askarel, but not silicone and mineral oils, on testicular steroidogenesis.
Assuntos
Arocloros/efeitos adversos , Bifenilos Policlorados/efeitos adversos , Hormônios Testiculares/biossíntese , Testículo/fisiologia , Animais , Técnicas de Cultura , Infusões Parenterais , Masculino , Ratos , Ratos Wistar , Testículo/efeitos dos fármacosRESUMO
The present in vitro studies using a suspension of Leydig cells from adult rat testis demonstrated that bromocriptine (BR, 2 x 10(-5)M) inhibits hCG-stimulated testosterone production (in the presence of submaximal and maximal doses of hCG), while basal production was unaffected. When the cells were exposed to 8-bromo-cAMP either in the presence or absence of hCG, the inhibitory effect of BR was not reversed. In intact cells, BR inhibited conversion of progesterone and 17-hydroxy-progesterone to testosterone while conversion of androstenedione was not affected. Incubation of homogenates of Leydig cells in the presence of limiting NADPH concentrations (< or = 0.1 mM) resulted in significant BR-induced inhibition of conversion of progesterone (10 microM) to testosterone, while in the presence of "high" concentrations of NADPH (> or = 0.5 mM) BR was without effect. Present results suggest that BR inhibits androgen production at the level of the microsomal enzymes 17 alpha-hydroxylase and/or 17,20-lyase. The inhibitory effect of BR using homogenates of Leydig cells was evident only in the presence of limiting NADPH concentrations that suggests a competitive-like pattern of inhibition, but mechanisms by which BR decreases activity of microsomal enzymes remain to be determined.
Assuntos
Aldeído Liases/antagonistas & inibidores , Androgênios/metabolismo , Bromocriptina/farmacologia , Inibidores das Enzimas do Citocromo P-450 , Células Intersticiais do Testículo/enzimologia , Esteroide 17-alfa-Hidroxilase/antagonistas & inibidores , Animais , Gonadotropina Coriônica/farmacologia , Cinética , Células Intersticiais do Testículo/efeitos dos fármacos , Células Intersticiais do Testículo/metabolismo , Masculino , Ratos , Ratos Wistar , Testosterona/metabolismoRESUMO
In rats, acute immobilization (IMO) stress (2 h) induced a fall in the serum androgen concentrations (T+DHT) without detectable changes in serum luteinizing hormone (LH) values. In vitro studies, using a suspension of Leydig cells from adult rat testis, demonstrated that acute stress inhibited conversion of progesterone (P) or 17hydroxyprogesterone (17OHP) to T while conversion of androstendione (delta 4 A) was not affected. Acute IMO reduced activity of 3 beta-hydroxysteroid dehydrogenase (3 beta-HSD) and decreased basal and hCG-stimulated progesterone and androgen production. Chronic IMO stress (2 h daily for 10 days) induced a decrease in serum androgen level with decline in serum LH values. In vitro, hCG-stimulated progesterone and androgen production by suspension of Leydig cells, as well as conversion of P and 17OHP to T were not significantly altered. Our data demonstrates that acute IMO stress impaired testicular steroidogenesis primarily at the testicular level (decreasing the activity of certain enzymes), while chronic IMO stress exerts the effect mainly on the hypothalamic-pituitary axis; reduced serum LH levels elicit a decrease in serum androgen levels.
Assuntos
Células Intersticiais do Testículo/metabolismo , Esteroides/biossíntese , Animais , Células Cultivadas , Imobilização , Células Intersticiais do Testículo/enzimologia , Masculino , Ratos , Esteroides/sangue , Estresse FisiológicoRESUMO
Previous studies indicate that acute immobilization stress (IMO; 2 h) impaired testicular steroidogenesis primarily at the testicular level decreasing the activity of certain steroidogenic enzymes. In the present study unstressed rats as well as IMO rats (2 h) were treated by intratesticular injection of naltrexone methobromide (NMB; peripheral opioid receptor antagonist; 36 microg/testis) or vehicle at the beginning of and at 1 h of the IMO period. In IMO rats the activity of P450c17 was significantly reduced as well as the activity of NADPH-P450 reductase (which catalyzes the transfer of electrons from NADPH to cytochrome P450), while the activity of NADH-b5 reductase was not affected. Present data confirmed previous results that acute IMO reduced testicular P450c17 activity and implicate that decreased activity of NADPH-P450 reductase could be responsible for the inhibition of P450c17 under IMO conditions, while NADH-b5 reductase is probably not involved. NMB treatment antagonized the inhibitory effect of IMO on P450c17 and NADPH-P450 reductase activities. Such results put forward the implication that endogenous opioid peptides are involved in mediating the inhibitory effect of IMO on testicular steroidogenesis, and allow the speculation that NADPH-P450 reductase could be a possible site of such an inhibition.
Assuntos
Células Intersticiais do Testículo/enzimologia , NADH NADPH Oxirredutases/metabolismo , Naltrexona/análogos & derivados , Estresse Fisiológico , Testículo/efeitos dos fármacos , 17-alfa-Hidroxiprogesterona/análogos & derivados , 17-alfa-Hidroxiprogesterona/metabolismo , Androstenodiona/metabolismo , Animais , Redutases do Citocromo/metabolismo , Citocromo-B(5) Redutase , Masculino , NADPH-Ferri-Hemoproteína Redutase , Naltrexona/farmacologia , Antagonistas de Entorpecentes/farmacologia , Progesterona/metabolismo , Compostos de Amônio Quaternário , Ratos , Ratos Wistar , Esteroide 17-alfa-Hidroxilase/metabolismo , Esteroides/metabolismo , Testosterona/metabolismoRESUMO
The messenger role of nitric oxide (NO) in immobilization stress-induced inhibition of testicular steroidogenesis has been previously suggested. In accord with this, here, we show that the intratesticular injection of isosorbide dinitrate (ISDN; 2x2.5 mg/testis), an NO donor, mimicked the action of stress on serum testosterone concentrations and hCG-stimulated testosterone production in rat testicular tissue. When added in vitro, ISDN inhibited testicular 3beta-hydroxysteroid dehydrogenase and 17alpha-hydroxylase/lyase. Immobilization stress and injections of ISDN also decreased the activity of catalase, glutathione peroxidase, glutathione transferase, and glutathione reductase in the interstitial compartment of testis. When stressed rats were treated concomitantly with bilateral intratesticular injections of N(omega)-nitro-L-arginine methyl ester, a non-selective NOS inhibitor (2x600 microg/testis), the activities of antioxidative enzymes, as well as serum testosterone concentration, were partially normalized. These results indicate that stress-induced stimulation of the testicular NO signalling pathway leads to inhibition of both steroidogenic and antioxidant enzymes.
Assuntos
Antioxidantes/metabolismo , Óxido Nítrico/metabolismo , Esteroides/biossíntese , Estresse Fisiológico/metabolismo , Testículo/metabolismo , Animais , Catalase/antagonistas & inibidores , Gonadotropina Coriônica/farmacologia , Inibidores Enzimáticos/farmacologia , Glutationa Peroxidase/antagonistas & inibidores , Glutationa Redutase/antagonistas & inibidores , Glutationa Transferase/antagonistas & inibidores , Técnicas In Vitro , Dinitrato de Isossorbida/farmacologia , Masculino , NG-Nitroarginina Metil Éster/farmacologia , Doadores de Óxido Nítrico/farmacologia , Óxido Nítrico Sintase/antagonistas & inibidores , Ratos , Ratos Wistar , Testículo/efeitos dos fármacos , Testosterona/biossíntese , Testosterona/sangueRESUMO
The effects of PCBs (mixture of 2, 3, 4, 5-tetra; 2, 2', 4, 5, 5'-penta; 2, 2', 3, 3', 6, 6'-hexa and 2, 2', 3, 3', 4, 4', 5, 5'-octa congeners) on androgen production were investigated by suspension of Leydig cells from adult rat testis. hCG-stimulated androgen production was significantly inhibited by PCBs while progesterone level was not affected. Progesterone supported testosterone production was also decreased by PCBs, while conversion of androstenedione to testosterone was unchanged. These results suggest that the activity of microsomal enzyme C21 side-chain cleavage P450 was decreased by PCB treatment of Leydig cells in vitro.
Assuntos
Androgênios/biossíntese , Células Intersticiais do Testículo/efeitos dos fármacos , Células Intersticiais do Testículo/metabolismo , Bifenilos Policlorados/toxicidade , Androstenodiona/metabolismo , Animais , Enzima de Clivagem da Cadeia Lateral do Colesterol/antagonistas & inibidores , Gonadotropina Coriônica/farmacologia , Poluentes Ambientais/toxicidade , Técnicas In Vitro , Masculino , Progesterona/metabolismo , Ratos , Ratos Wistar , Testosterona/biossínteseRESUMO
The participation of the nitric oxide (NO) pathway in downregulation of testicular steroidogenesis in normal and stressed rats was investigated both in vivo and in vitro. In Leydig cells from normal animals, isosorbide dinitrate, an NO donor, decreased the human chorionic gonadotropin (CG)-stimulated and progesterone-derived androgen production. Also, the intratesticular injection of a precursor of NO, arginine (10 mg/testis), transiently decreased serum androgen levels and inhibited human CG-stimulated androgen production in acute testicular cultures. These effects were eliminated in rats cotreated with Nomega-nitro-L-arginine methyl ester (L-NAME) (2 X 600 microg/each testis). Acute immobilization stress (2 h) decreased serum androgen levels and inhibited human CG-stimulated androgen production in vitro. These effects were accompanied by a significant increase in nitrite, a stable oxidation product of NO, in testicular cultures. Bilateral intratesticular injection of L-NAME prevented the stress-induced decrease of human CG-stimulated androgen production, and significantly reduced the nitrite levels. These results implicate NO in normal and stress-impaired testicular steroidogenesis.
Assuntos
Óxido Nítrico/fisiologia , Esteroides/biossíntese , Estresse Psicológico/metabolismo , Testículo/metabolismo , Animais , Arginina/farmacologia , Inibidores Enzimáticos/farmacologia , Imobilização , Masculino , NG-Nitroarginina Metil Éster/farmacologia , Óxido Nítrico Sintase/antagonistas & inibidores , Nitritos/sangue , Ratos , Ratos Wistar , Testículo/efeitos dos fármacos , Testosterona/sangueRESUMO
The present study examined the effects of naloxone (N) and naltrexone-methobromide (NMB; an opioid receptor antagonist that does not cross the blood-brain barrier) on testicular steroidogenesis during acute immobilization stress (IMO; 2 h) in adult rats. Unstressed rats as well as IMO rats were treated by unilateral intratesticular injection of N (20 micrograms/testis), NMB (36 micrograms/testis), or vehicle at the beginning of and at 1 h of the IMO period. In IMO rats serum T levels were significantly reduced, while serum luteinizing hormone levels were not affected. N and NMB normalized serum T levels in IMO rats and had no effects in controls. In IMO rats the activities of 3 beta-hydroxysteroid dehydrogenase (HSD) and P450(17 alpha, lyase) were significantly reduced, while the activity of 17 beta-HSD was not affected. N and NMB antagonized the inhibitory effect of IMO on 3 beta-HSD and P450(17 alpha, lyase) but did not alter enzyme activity in freely moving rats. Acute IMO decreased basal and human chorionic gonadotropin-stimulated androgen production by hemitestis preparation, but N (10(-4) M) added directly to the incubation medium blocked the decrease and had no effect on testes from freely moving control rats. These results support the conclusion that endogenous opioid peptides are potentially important paracrine regulators of testicular steroidogenesis under stress conditions.
Assuntos
Naloxona/farmacologia , Naltrexona/análogos & derivados , Antagonistas de Entorpecentes/farmacologia , Estresse Fisiológico/metabolismo , Testículo/efeitos dos fármacos , Testículo/metabolismo , 3-Hidroxiesteroide Desidrogenases/metabolismo , Animais , Injeções , Masculino , Naloxona/administração & dosagem , Naltrexona/administração & dosagem , Naltrexona/farmacologia , Compostos de Amônio Quaternário , Ratos , Ratos Wistar , Restrição Física , Testosterona/biossíntese , Testosterona/sangueRESUMO
Starting from a 16-oximino derivative of 5-androstene the newly-synthesized 16-oximino-17-hydroxy-17-substituted derivatives 2-4 gave by the Beckmann fragmentation reaction the corresponding D-seco derivatives 6-9. Besides, in the case of the 17-hydroxy-17-methyl-16-oximino derivative 2, as a result of the rearrangement, the hydrolysis product 5 of the 16-oximino group with the opposite configuration at the C-17 was obtained. By the Oppenauer oxidation and/or by dehydration of 7 with 2,3-dichloro-5,6-dicyanobenzoquinone (DDQ), the corresponding derivatives 12, 13, and 14 were obtained. The structures of 6 and 12 were unambiguously proved by the appropriate X-ray structural analysis. Kinetic analysis for anti-aromatase activity showed that compound 12 expressed the highest inhibition in the denucleated rat ovarian fraction in comparison to other androstene derivatives (IC(50) was 0.42 microM). In comparison to aminoglutethimide (AG) activity, it was 3.5 times lower. The inhibition was competitive, with K(i) of 0.27 microM. Introduction of additional units of unsaturation (compounds 13 and 14) in D-seco derivatives did not increase anti-aromatase activity.
Assuntos
Androstanos/química , Androstanos/farmacologia , Inibidores da Aromatase , Animais , Benzoquinonas/farmacologia , Ligação Competitiva , Cristalografia por Raios X , Feminino , Hidrólise , Concentração Inibidora 50 , Cinética , Espectroscopia de Ressonância Magnética , Modelos Moleculares , Ratos , Ratos WistarAssuntos
Encéfalo/fisiologia , Sincronização Cortical , Eletroencefalografia , Sono , Animais , Nível de Alerta , Mapeamento Encefálico , Gatos , Aqueduto do Mesencéfalo/fisiologia , Ventrículos Cerebrais/fisiologia , Corpo Caloso/fisiologia , Diencéfalo/fisiologia , Eletrofisiologia , Feminino , Corpos Geniculados/fisiologia , Hipocampo/fisiologia , Hipotálamo/fisiologia , Sistema Límbico/fisiologia , Masculino , Vias Neurais , Condutos Olfatórios/fisiologia , Septo Pelúcido/fisiologia , Fases do Sono , Teto do Mesencéfalo/fisiologia , Tegmento Mesencefálico/fisiologia , Lobo Temporal/fisiologia , Tálamo/fisiologia , Vias Visuais/fisiologia , VigíliaAssuntos
Aves/fisiologia , Sono , Animais , Ritmo Circadiano , Escuridão , Eletroencefalografia , Eletromiografia , Movimentos Oculares , Frequência Cardíaca , Luz , Atividade Motora , Respiração , Sono REM , VigíliaRESUMO
The adsorption of heavy metal ions from synthetic solutions was performed using sawdust of beech, linden and poplar trees. The adsorption depends on the process time, pH of the solution, type of ions, initial concentration of metals and the sawdust concentration in suspension. The kinetics of adsorption was relatively fast, reaching equilibrium for less than 20 min. The adsorption equilibrium follows Langmuir adsorption model. The ion exchange mechanism was confirmed assuming that the alkali-earth metals from the adsorbent are substituted by heavy metal ions and protons. On lowering the initial pH, the adsorption capacity decreased, achieving a zero value at a pH close to unity. The maximum adsorption capacity (7-8 mg g(-1) of sawdust) was achieved at a pH between 3.5 and 5 for all the studied kinds of sawdust. The initial concentration of the adsorbate and the concentration of sawdust strongly affect the process. No influence of particles size was evidenced. A degree of adsorption higher than 80% can be achieved for Cu(2+) ions but it is very low for Fe(2+) ions, not exceeding 10%.
Assuntos
Íons , Metais Pesados/química , Adsorção , Concentração de Íons de Hidrogênio , Cinética , Metais , Tamanho da Partícula , Prótons , Espectrofotometria Atômica , Espectrofotometria Ultravioleta/métodos , Fatores de Tempo , Árvores , Eliminação de Resíduos Líquidos/métodos , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/isolamento & purificação , Purificação da Água/métodos , MadeiraRESUMO
Young adult Louis rats were implanted for chronic sleep recording to test the effect of diethyldithiocarbamate (DDC) on sleep. Recordings of EEG and EMG were done continuously for 12 h during the 12 consecutive days. There were 2 days of baseline recording, 3 days of recording with a single daily injection of placebo, 3 days of recording with a single daily injection of DDC (500 mg/kg i.p.), and 3 days of DDC withdrawal recording with placebo injection. Placebo injections did not change the proportion of time spent in different behavioural states. With daily injection of DDC there was an increase in wakefulness, no change in slow-wave sleep and elimination or drastic reduction in paradoxical sleep (PS). There was no PS rebound during the DDC withdrawal days. These results suggest that the reduction of PS produced by DDC and the absence of PS rebound may be due to a lowering in norepinephrine in the brain. In other experiments rats were injected with DDC (500 mg/kg i.p.) daily for 3 days and whole brains were analysed chemically. Norepinephrine was significantly decreased, while 5-hydroxytryptamine, 5-hydroxyindolacetic acid, dopamine and homovanilic acid were unchanged. Seizure activity appeared during relaxed wakefulness in all rats treated with DDC. Taken together it seems that lowering of brain NE is responsible for the appearance of seizure activity and also, for PS reduction. PS reduction might, per se, produce seizure activity.