Navegando por Palavras-chave "Bothrops jararaca venom"
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- ItemSomente MetadadadosBrain nitric oxide production by a proline-rich decapeptide from Bothrops jararaca venom improves baroreflex sensitivity of spontaneously hypertensive rats(Nature Publishing Group, 2010-12-01) Lameu, Claudiana; Pontieri, Vera; Guerreiro, Juliano R.; Oliveira, Eduardo F. [UNIFESP]; Silva, Carlos Alberto da; Giglio, Joyce M.; Melo, Robson L.; Campos, Ruy Ribeiro [UNIFESP]; Martins de Camargo, Antonio Carlos; Ulrich, Henning; Universidade de São Paulo (USP); Inst Butantan; Universidade Federal de São Paulo (UNIFESP); Univ Fed FABCBaroreflex sensitivity is disturbed in many people with cardiovascular diseases such as hypertension. Brain deficiency of nitric oxide (NO), which is synthesized by NO synthase (NOS) in the citrulline-NO cycle (with argininosuccinate synthase (ASS) activity being the rate-limiting step), contributes to impaired baroreflex. We recently showed that a decapeptide isolated from Bothrops jararaca snake venom, denoted Bj-PRO-10c, exerts powerful and sustained antihypertensive activity. Bj-PRO-10c promoted vasodilatation dependent on the positive modulation of ASS activity and NO production in the endothelium, and also acted on the central nervous system, inducing the release of GABA and glutamate, two important neurotransmitters in the regulation of autonomic systems. We evaluated baroreflex function using the regression line obtained by the best-fit points of measured heart rate (HR) and mean arterial pressure (MAP) data from spontaneously hypertensive rats (SHRs) treated with Bj-PRO-10c. We also investigated molecular mechanisms involved in this effect, both in vitro and in vivo. Bj-PRO-10c mediated an increase in baroreflex sensitivity and a decrease in MAP and HR. the effects exerted by the peptide include an increase in the gene expression of endothelial NOS and ASS. Bj-PRO-10c-induced NO production depended on intracellular calcium fluxes and the activation of a G(i/o)-protein-coupled metabotropic receptor. Bj-PRO-10c induced NO production and the gene expression of ASS and endothelial NOS in the brains of SHRs, thereby improving baroreflex sensitivity. Bj-PRO-10c may reveal novel approaches for treating diseases with impaired baroreflex function. Hypertension Research (2010) 33, 1283-1288; doi: 10.1038/hr.2010.208
- ItemSomente MetadadadosThe effect of experimental Bothrops jararaca envenomation on pregnant mice(Elsevier B.V., 2006-02-01) Spadacci-Morena, D. D.; Tomy, S. C. de; Sano-Martins, I. S.; Katz, S. G.; Butantan Inst; Universidade Federal de São Paulo (UNIFESP)The injury caused by the intramuscular injection of a single dose of Bothrops jararaca venom (0.24 mg/kg body weight) to mice on day 8 of pregnancy and examined on day 9 was investigated. Macroscopic and histological examination showed that the bothropic venom caused an increase in the incidence of fetal resorptions. Histologically, a characteristic involution of mature decidua was noticed in saline-treated mice; however, necrotic trophoblast giant cells and decidual cells were also present in this region of mice treated with B. jararaca venom, mainly close to the embryo. Hemorrhagic areas were also observed at maternal-fetal interface, which contained maternal erythrocytes and polymorphonuclears. Plasma fibrinogen levels were lower in envenomed group (p <= 0.0001), but prothrombin time and activated partial thromboplastin time remained unaltered. Total and differential white blood cell counts were not statistically different between groups. Thus, B. jararaca venom causes injuries not only to the fetus, but also to decidual tissue and blood coagulation of pregnant mice. It is not clear, nonetheless, whether disturbances during the development of pregnancy are due to a direct effect of venom on uterus/fetus or to homeostatic changes in dams, such as clotting disturbances, or to both of them. (c) 2005 Elsevier B.V. All rights reserved.
- ItemAcesso aberto (Open Access)Envenenamento experimental por Bothrops jararaca em camundongos prenhes: Eficácia do soro antibotrópico(Universidade Federal de São Paulo (UNIFESP), 2011-03-30) Ferreira, Karla Vanessa [UNIFESP]; Godosevicius, Sima [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)Introduction: Snakebite accidents are considered a rare event among pregnant women, but serotherapy is indicated even when envenomation is not severe. However, antivenom can cause maternal adverse reactions and consequently fetal death. Experimental Bothrops jararaca (Bj) envenomation can provoke marked morphological alterations in the antimesometrial (AM) region of uterus in pregnant mice which can culminate in the end of gestation. This investigation aimed to verify whether Bothrops antivenom (BAV) could restore the normal morphology of murine uterus, after Bj envenomation. Methods: On the morning of day 7,5 of pregnancy, animals received Bj venom (0.24mg Bj venom/kg body weight) i.m., and after 3 hours they were treated with BAV i.v. (VBj+BAV). Control groups received saline and was treated with BAV (Sal+BAV) or Bj venom (VBj). On day 8,5, uterine morphology was analyzed, especially at the maternal-fetal interface in the AM region. Plasma fibrinogen (Fg) was assayed in plasma samples of pregnant animals. Aiming to study the external appearance and the skeletal morphology of fetuses, as well as the incidence of fetal resorptions, another group of animals on day 7,5 received the same treatments mentioned and was sacrificed on day 18,5. Results: Histological analysis of most dams of the VBj group revealed the maternal and fetal tissues disorganized, showing hemorrhagic areas and a prominent inflammatory infiltrate at the maternal-fetal interface. Additionally, decidual cells (maternal) and trophoblastic giant cells (fetal) exhibited evident signs of necrosis. The antimesometrial decidua of most dams of the VBj+BAV revealed the maternal fetal tissues organized, similarly to the uteri of dams of the Sal+BAV group. Analyses of the external appearance and skeletal morphology of fetuses on day 18,5 showed no difference among groups; however, the dams that received Sal+BAV and were treated with ABS showed smaller fetuses than VBj+BAV group. Plasma Fg levels of the VBj+BAV group were similar to those of Sal+BAV group. However, experimental Bj envenomation showed lower plasma Fg levels. Conclusion: Our results indicated that the treatment with the antibothropic serum was capable to maintain the development of the gestation, preserving the morphology in the maternal-fetal interface, in the animals.
- ItemSomente MetadadadosA novel phospholipase A2, BJ-PLA2, from the venom of the snake Bothrops jararaca: Purification, primary structure analysis, and its characterization as a platelet-aggregation-inhibiting factor(Academic Press Inc, 1999-07-01) Serrano, Solange Maria de Toledo [UNIFESP]; Reichl, Antonia P.; Mentele, Reinhard; Auerswald, Ennes A.; Santoro, Marcelo Larami; Sampaio, Claudio Augusto Machado [UNIFESP]; Camargo, Antonio Carlos Martins de [UNIFESP]; Assakura, Marina Tizuko; Inst Butantan; Universidade Federal de São Paulo (UNIFESP); Univ MunichThis paper describes the isolation and primary structure analysis of a new phospholipase A2 with platelet-aggregation-inhibiting activity from the venom of Bothrops jararaca. the protein, named BJ-PLA2, was isolated by means of ammonium sulfate precipitation and anion-exchange and reversed-phase chromatographies and behaved as a homogeneous single-chain protein on SDS-PAGE. Its amino acid sequence was determined by N-terminal sequencing and analysis of overlapped chemical and proteolytic fragments by automated Edman degradation and mass spectometry determination. BJ-PLA2 consists of 124 amino acid residues and has the structural features of snake venom class II phospholipases A2, Chemical modification with p-bromophenacylbromide caused complete loss of enzymatic activity and partially affected the platelet-aggregation-inhibiting activity of BJ-PLA2. (C) 1999 Academic Press.
- ItemSomente MetadadadosProteomic identification of gender molecular markers in Bothrops jararaca venom(Elsevier Science Bv, 2016) Zelanis, Andre [UNIFESP]; Menezes, Milene C.; Kitano, Eduardo S.; Liberato, Tarcisio [UNIFESP]; Tashima, Alexandre Keiji [UNIFESP]; Pinto, Antonio F. M.; Sherman, Nicholas E.; Ho, Paulo L.; Fox, Jay W.; Serrano, Solange Maria de Toledo [UNIFESP]Variation in the snake venom proteome is a well-documented phenomenon