We have demonstrated that central administration of zinc in minute amounts induces a significant antidipsogenic action in dehydrated rats as well as in rats under central cholinergic and angiotensinergic stimulation. Here we show that acute third ventricle injections of zinc also block water intake induced by central ß-adrenergic stimulation in Wistar rats (190-250 g). Central inhibition of opioid pathways by naloxone reverses the zinc-induced antidipsogenic effect in dehydrated rats. After 120 min, rats receiving third ventricle injections of isoproterenol (160 nmol/rat) exhibited a significant increase in water intake (5.78 ± 0.54 ml/100 g body weight) compared to saline-treated controls (0.15 ± 0.07 ml/100 g body weight). Pretreatment with zinc (3.0, 30.0 and 300.0 pmol/rat, 45 min before isoproterenol injection) blocked water intake in a dose-dependent way. At the highest dose employed a complete blockade was demonstrable (0.54 ± 0.2 ml/100 g body weight). After 120 min, control (NaAc-treated) dehydrated rats, as expected, exhibited a high water intake (7.36 ± 0.39 ml/100 g body weight). Central administration of zinc blocked this response (2.5 ± 0.77 ml/100 g body weight). Naloxone pretreatment (82.5 nmol/ rat, 30 min before zinc administration) reverted the water intake to the high levels observed in zinc-free dehydrated animals (7.04 ± 0.56 ml/ 100 g body weight). These data indicate that zinc is able to block water intake induced by central ß-adrenergic stimulation and that zincinduced blockade of water intake in dehydrated rats may be, at least in part, due to stimulation of central opioid peptides.
Correspondence
The aim of the present study was to investigate the role of central 5-HT3 receptors on the control of blood glucose in stressed and non-stressed rats in both fasted and fed states. Adult Wistar male rats had each their third ventricle cannulated 7 days before the experiments. Injections of m-CPBG, a selective 5-HT3 receptor agonist, induced a significant increase in blood glucose in non-stressed rats in both fasted and in fed states. The same procedure was unable to modify stress-induced hyperglycemia. The hyperglycemic effect of m-CPBG central administration was blocked by pretreatment with ondansetron, a specific 5-HT3 receptor antagonist, indicating that the effects here obtained with m-CPBG were a result of its interaction with 5-HT3 receptors. Third ventricle injections of ondansetron alone were not able to modify blood glucose in non-stressed animals and did not change the hyperglycemic responses observed after immobilization stress. We conclude that pharmacological activation of the central 5-HT3 receptor induces a hyperglycemic effect in non-stressed animals.
Introduction Myelin oligodendrocyte glycoprotein (MOG) is a nervous system protein expressed by oligodendrocytes to constitute the myelin sheath. Autoantibodies against MOG have been widely described in neurological and autoimmune diseases such as MOG-IgG-associated disorder (MOGAD). Although underlying mechanisms have not yet been understood, an overlap of MOGAD and Systemic Lupus Erythematosus (SLE) has been shown in the literature. Objectives The aim of this systematic review was to assess the possible correlations between MOGAD and SLE based on reported features found in the literature that support the association of the two. Methods A keyword-based literature search was conducted, applying a ten-year filter and using the following key-words: “MOG autoantibody-associated disease and Systemic Lupus Erythematosus”; “MOG and Systemic Lupus Erythematosus” “Anti-MOG and Lupus”; “MOG and SLE”; “MOG and LUPUS” on MEDLINE/PUBMED, ScienceDirect, SciELO, LILACS and Cochrane; and “MOG antibody-associated disease and SLE” on Google Scholar. Results Eleven publications reporting on the MOGAD and SLE correlation were included in qualitative synthesis: animal experiment (1), cross-sectional (3), prospective (2), retrospective (1), non-systematic review (3), and case report (1) studies. Conclusion Not much is known about the connection between MOG-IgG-associated disorder and SLE. Unfortunately, only observational studies have been conducted in humans so far, providing us with limited data. While MOGAD features have been reported to develop in SLE patients, this is not an universal finding. In fact, many different issues impair these results, making it difficult to match the findings of different studies.
There have been several clinical manifestations associated with SARS-CoV-2 infection since 2019, including dermatological signs and symptoms. In this article, the authors report a case of a previously healthy patient with COVID-19 who was mistakenly diagnosed with dengue fever due to the skin rash. By the time the patient's investigation was initiated, Joinville (Santa Catarina, Brazil) had approximately 5,000 confirmed cases of dengue fever and 1,700 cases of COVID-19 in 2020. Thus, the authors emphasize that in endemic regions such as Brazil, the two diseases must be considered until proven otherwise. Finally, the authors warn of the possibility of co-infection with these two viruses in regions that are fighting both epidemics at the same time.
The emergence of SARS-CoV-2 is a challenge in the actual medical scenario. Besides the classical lung and respiratory disease, patients infected with the virus can present with cardiac injury, and pathogenic mechanisms point to a direct infection of the heart.
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