Navegando por Autor "Alves, Leandro Miranda"
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Item Pyridostigmine blunts the increases in myocardial oxygen demand elicited by the stimulation of the central nrvous system in anesthetized rats.(1999) Guimarães, Andrea Grabe; Alves, Leandro Miranda; Tibiriçá, Eduardo Vera; Nobrega, Antonio Claudio Lucas daThe purpose of the present work was to verify the effect of pyridostigmine bromide, a reversible cholinesterase inhibitor, on the increases in cardiac work and myocardial oxygen demand produced by central sympathetic stimulation in pentobarbitalanesthetized Wistar rats. The pharmacological stimulation of the central nervous system with L-glutamate (1 mg/kg, intracerebroventricular) elicited marked increases in arterial pressure, dP/dtma~, rate-pressure product, and triple product, reproducing the cardiovascular alterations observed during physical effort and stressful situations. The oral administration of pyridostigmine bromide (5, 10 and 20 mg/kg) 2 hours before central stimulation blunted the increases in mean arterial pressure, dP/dt .... and triple product elicited by glutamate (29, 28 and 57% for 5 mg/kg; 26, 23 and 46% for 10 mg/kg and 19, 17 and 37% for 20 mg/kg, respectively) when compared to the control group (41, 49 and 106%, respectively; p < 0.05). Our results also showed that the activity of plasmatic cholinesterase was effectively inhibited by pyridostigmine bromide. In conclusion, the increases in endogenous acetylcholine induced by cholinesterase inhibition blunted the centrally-evoked increases in myocardial oxygen demand in anesthetized rats. This effect could represent a cardioprotective action in a situation of ischemic heart disease.Item The pollutant organotins leads to respiratory disease by inflammation : a mini-review.(2018) Silva, Albená Nunes da; Dittz, Dalton; Santana, Higor Scardini; Faria, Rodrigo Alves; Freitas, Katia Michelle; Coutinho, Christiane Rabelo; Rodrigues, Livia Carla de Melo; Alves, Leandro Miranda; Silva, Ian Victor; Graceli, Jones Bernardes; Lima, Leandro Ceotto FreitasOrganotins (OTs) are organometallic pollutants. The OTs are organometallic pollutants that are used in many industrial, agricultural, and domestic products, and it works as powerful biocidal compound against large types of microorganisms such as fungi and bacteria. In addition, OTs are well known to be endocrine-disrupting chemicals, leading abnormalities an “imposex” phenomenon in the female mollusks. There are some studies showing that OTs’ exposure is responsible for neural, endocrine, and reproductive dysfunctions in vitro and in vivo models. However, OTs’ effects over the mammalian immune system are poorly understood, particularly in respiratory diseases. The immune system, as well as their cellular components, performs a pivotal role in the control of the several physiologic functions, and in the maintenance and recovery of homeostasis. Thus, it is becoming important to better understand the association between environmental contaminants, as OTs, and the physiological function of immune system. There are no many scientific works studying the relationship between OTs and respiratory disease, especially about immune system activation. Herein, we reported studies in animal, humans, and in vitro models. We searched studies in PUBMED, LILACS, and Scielo platforms. Studies have reported that OTs exposure was able to suppress T helper 1 (Th1) and exacerbate T helper 2 (Th2) response in the immune system. In addition, OTs’ contact could elevate in the airway inflammatory response, throughout a mechanism associated with the apoptosis of T-regulatory cells and increased oxidative stress response. In addition, OTs induce macrophage recruitment to the tissue, leading to the increased necrosis, which stimulates an inflammatory cytokines secretion exacerbating the local inflammation and tissue function loss. Thus, the main intention of this mini-review is to up to date the main findings involving the inflammatory profile (especially Th1 and Th2 response) in the respiratory tract as a result of OTs’ exposure.