Navegando por Palavras-chave "Pinealectomy"
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- ItemAcesso aberto (Open Access)Melatonin treatment decreases c-fos expression in a headache model induced by capsaicin(Springer, 2009-04-01) Tanuri, Fabiano da Cunha [UNIFESP]; Lima, Eliângela de [UNIFESP]; Peres, Mario Fernando Prieto [UNIFESP]; Cabral, Francisco Romero [UNIFESP]; Naffah-Mazzacoratti, Maria da Graca [UNIFESP]; Cavalheiro, Esper Abrão [UNIFESP]; Cipolla-Neto, Jose; Zukerman, Eliova [UNIFESP]; Amado, Débora [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); Hosp Israelita Albert Einstein; Universidade de São Paulo (USP)The aim of the present work was to analyze c-fos response within the trigeminal nucleus caudalis (TNC) of pinealectomized rats and animals that received intraperitoneal melatonin, after intracisternal infusion of capsaicin, used to induce intracranial trigeminovascular stimulation. Experimental groups consisted of animals that received vehicle solution (saline-ethanol-Tween 80, 8:1:1, diluted 1:50) only (VEI, n = 5); animals that received capsaicin solution (200 nM) only (CAP, n = 6); animals submitted to pinealectomy (PX, n = 5); sham-operated animals (SH, n = 5); animals submitted to pinealectomy followed by capsaicin stimulation (200 nM) after 15 days (PX + CAP, n = 7); and animals that received capsaicin solution (200 nM) and intraperitoneal melatonin (10 mg/kg) (CAP + MEL, n = 5). Control rats, receiving vehicle in the cisterna magna, showed a small number of c-fos-positive cells in the TNC (layer I/II) as well as the sham-operated and pinealectomized rats, when compared to animals stimulated by capsaicin. On the other hand, pinealectomized rats, which received capsaicin, presented the highest number of c-fos-positive cells. Animals receiving capsaicin and melatonin treatment had similar expression of the vehicle group. Our data provide experimental evidence to support the role of melatonin and pineal gland in the pathophysiology of neurovascular headaches.
- ItemAcesso aberto (Open Access)Melatonina e o tecido adiposo marrom em machos adultos(Universidade Federal de São Paulo (UNIFESP), 2018-11-29) Pereira, Caroline Aparecida [UNIFESP]; Amaral, Fernanda Gaspar do [UNIFESP]; http://lattes.cnpq.br/6398402888086154; http://lattes.cnpq.br/9501556756194090; Universidade Federal de São Paulo (UNIFESP)Aim: Evaluate the role of melatonin in the metabolism of brown adipose tissue (BAT) in male adult rats. Methods: Wistar rats (8 weeks) were assigned to three groups: Control, Pinealectomized (PINX) and Pinealectomized treated with oral melatonin (1mg/ kg, PINX/Mel) and kept in a room with controlled 12h/12h light/dark cycle (ZT0 beginning of light phase and ZT12 beginning of the dark phase). Animals were followed up for 13 weeks when euthanasia and tissue analysis occurred. The experimental design included two distinct approaches, named: 1) animals from all groups were euthanized every 3 hours over 24 hours (n = 4 animals/ZT/group) without any challenge to BAT, and 2) animals from all groups were submitted to acute BAT challenge due to cold exposure or high fat diet (HFD) at the end of the experimental period, when they were submitted to euthanasia in ZT10. BAT was collected for the evaluation of gene expression by realtime PCR, quantification of enzymatic activity by kinetic assay, protein expression by Western Blotting and rhythmic analysis by the method of Cosinor. Results: PINX animals presented changes in the gene expression of Dio2, Lhs, Ucp1, Pgc1α and Cidea, differing from the other groups over 24 hours. Similar results were seen in the UCP1 protein expression in identical condition. These changes in PINX animals resulted in rhythmic imbalance that included phase advances, phase delays and no fit to the cosine model, suggesting loss of rhythmicity in the expression of these genes. Regarding protein quantification and enzymatic activity of mitochondrial complexes I, II and IV and the ratio between both, isolated statistical differences were observed and they cannot suggest an effective role of melatonin on these complexes in unchallenged BAT. However, the results point to a rhythmic desynchronization of these complexes in the PINX group. PINX animals acutely fed with HFD (BAT metabolic challenge) presented lower amount of Dio2 transcripts and the HFD PINX/Mel animals had a higher expression of Dio2, Ucp1 and Cidea. Coldexposed PINX rats showed decreased Dio2 and Lhs expression, and melatonin treatment caused higher Adrβ3, Dio2, Ucp1 and Cidea expression and lower Pgc1α expression in the PINX/Mel group. These data suggest that the absence of melatonin impairs BAT responses to metabolic challenges and that melatonin replacement reverses this effect. Conclusion: Based on the analysis of the data presented here, we can conclude that melatonin plays an important role in several key points of the thermogenic activation pathway, influencing both the rhythmic profile of the tissue and its ability to respond to metabolic challenges, that is crucial for the organism homeostasis.
- ItemSomente MetadadadosPinealectomy changes rat ovarian interstitial cell morphology and decreases progesterone receptor expression(Parthenon Publishing Group, 2003-04-01) Soares Júnior, José Maria [UNIFESP]; Simões, Manuel de Jesus [UNIFESP]; Oshima, Celina Tizuko Fujiyama [UNIFESP]; Mora, Oswaldo Alves [UNIFESP]; Lima, Geraldo Rodrigues de [UNIFESP]; Baracat, Edmund Chada [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); Fdn Oncoctr São PauloThe aim of this study was to evaluate the rat ovarian morphological and function changes after pinealectomy (Px). Two months after px, young female Wistar rats were sacrificed and the right ovaries were analysed morphologically and the left ovaries were used for steroid receptor binding experiments. Blood was collected and steroid hormone and melatonin levels were measured using radioimmunoassay kits.Results revealed that in the px group the rat ovaries had an. increase in the number of atretic follicles and interstitial cells. These cells showed hyperactivity features on transmission electron microscopy and morphometric analysis (p < 0.05 compared with control and sham groups). Px-group serum showed an increase in estradiol (p < 0.05) and a decrease in progesterone levels (p < 0.05) compared with other groups. Moreover, progesterone receptor expression was lower than control and sham groups (p < 0.05).We postulate that pinealectomy leads to many morphological alterations of rat ovaries that are associated with functional changes in steroidogenesis and a decrease in progesterone receptor expression.