Chronic inhalation exposure to the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) alters cardiac collagen in Wistar rats.

Introduction: 2,4-dichlorophenoxyacetic acid (2,4-D) is one of the most used in the world and exposure to herbicides can affect animals and humans, causing toxic effects that include cardiotoxicity. This is the first study to evaluate cardiac remodeling after experimental simulation of environmental exposure by chronic inhalation (6 months) to the herbicide 2,4-D.

Methods: Thirty male Wistar rats were exposed to two different concentrations of the 2,4-D formulation (low - 187.

The high-intensity interval training mitigates the cardiac remodeling in spontaneously hypertensive rats.

Aim: To evaluate the influence of high-intensity interval training (HIIT) on cardiac structural and functional characteristics and myocardial mitogen-activated protein kinase (MAPK) signaling in hypertensive rats.

Methods: Male rats (12 months old) were divided into three groups: Wistar Kyoto rats (WKY, n = 8); sedentary spontaneously hypertensive rats (SED-SHR, n = 10), and trained spontaneously hypertensive rats (HIIT-SHR, n = 10). Systolic blood pressure (SBP), functional capacity, echocardiography, isolated papillary muscle, and gene expression of MAPK gene-encoding proteins associated with Elk1, cJun, ATF2, MEF2 were analyzed.

Comparison of biological activities of venom from two Colombian regions.

Background: In the present study, we have tested whether specimens of the medically relevant scorpion , collected from two climatically and ecologically different regions, differ in the biological activities of the venom.

Methods: Scorpions were collected in Tolima and Huila, Colombia. Chemical profiles of the crude venom were obtained from 80 scorpions for each region, using SDS-PAGE and RP-HPLC.

Prospective study of a venom batch (Bj2015) - phospholipase A activity, immunogenicity, neurotoxicity, and myotoxicity parameters.

venom's (Bj2015) batch was biomonitored quarterly for one year to assess phospholipase A (PLA) activity, immunogenicity, neurotoxicity, and myotoxicity. models were applied to evaluate losses using decay model and recoveries by predictive trend analysis. Mice were immunized with Bj2015.

Pharmacological Properties of (Vochysiaceae) Extract to Neutralize the Neuromuscular Blockade Induced by Bothropstoxin-I (Lys49 Phospholipase A) Myotoxin.

Bothrops snakes are responsible for more than 70 % of snakebites every year in Brazil and their venoms cause severe local and systemic damages. The pharmacological properties of medicinal plants have been widely investigated in order to discover new alternative treatments for different classes of diseases including neglected tropical diseases as envenomation by snakebites. In this work, we have investigated the ability of Vochysia haenkeana stem barks extract (VhE) to neutralize the neuromuscular effects caused by Bothropstoxin-I (BthTX-I), the major phospholipase A (PLA) myotoxin from B.

Neutralising ability of Terminalia fagifolia extract (Combretaceae) against the in vitro neuromuscular effects of Bothrops jararacussu venom.

The ability of Terminalia fagifolia hydroalcoholic extract (Tf-HE) to neutralise the paralysis and myotoxicity induced by Bothrops jararacussu venom was assayed using mouse phrenic nerve-diaphragm (PND) preparation and two varieties of chick biventer cervicis (BC) preparations. Tf-HE 100 μg/mL and 500 μg/mL were tested against 40 and 200 μg of venom/mL in PND and BC preparations, respectively, using pre- and post-venom incubation treatments. The effects of Tf-HE against the myotoxicity caused by venom were evaluated via histological analysis (PND) and creatine kinase (CK) release (BC).

Ultrastructural aspects of mouse nerve-muscle preparation exposed to Bothrops jararacussu and Bothrops bilineatus venoms and their toxins BthTX-I and Bbil-TX: Unknown myotoxic effects.

Bites by Bothrops snakes normally induce local pain, haemorrhage, oedema and myonecrosis. Mammalian isolated nerve-muscle preparations exposed to Bothrops venoms and their phospholipase A toxins (PLA ) can exhibit a neurotoxic pattern as increase in frequency of miniature end-plate potentials (MEPPs) as well as in amplitude of end-plate potentials (EPPs); neuromuscular facilitation followed by complete and irreversible blockade without morphological evidence for muscle damage. In this work, we analysed the ultrastructural damage induced by Bothrops jararacussu and Bothrops bilineatus venoms and their PLA toxins (BthTX-I and Bbil-TX) in mouse isolated nerve-phrenic diaphragm preparations (PND).

Biological activities of Leptodeira annulata (banded cat-eyed snake) venom on vertebrate neuromuscular preparations.

The physiological properties of colubrid snake venoms are largely unknown and less frequently investigated. In this study, we assessed the enzymatic properties and biological activities of Leptodeira annulata (banded cat-eyed snake) venom, an opistoglyphous snake from Colombia. The proteolytic, phospholipase A2 and amidolytic activities are assessed using colorimetric assays and the biological activities were analyzed in avian and mammalian neuromuscular preparations.

The neuromuscular activity of Bothriopsis bilineata smaragdina (forest viper) venom and its toxin Bbil-TX (Asp49 phospholipase A2) on isolated mouse nerve-muscle preparations.

The presynaptic action of Bothriopsis bilineata smaragdina (forest viper) venom and Bbil-TX, an Asp49 PLA2 from this venom, was examined in detail in mouse phrenic nerve-muscle (PND) preparations in vitro and in a neuroblastoma cell line (SK-N-SH) in order to gain a better insight into the mechanism of action of the venom and associated Asp49 PLA2. In low Ca(2+) solution, venom (3μg/ml) caused a quadriphasic response in PND twitch height whilst at 10μg/ml the venom additionally induced an abrupt and marked initial contracture followed by neuromuscular facilitation, rhythmic oscillations of nerve-evoked twitches, alterations in baseline and progressive blockade. The venom slowed the relaxation phase of muscle twitches.

Neuromuscular activity of Micrurus laticollaris (Squamata: Elapidae) venom in vitro.

In this work, we have examined the neuromuscular activity of Micrurus laticollaris (Mexican coral snake) venom (MLV) in vertebrate isolated nerve-muscle preparations. In chick biventer cervicis preparations, the MLV induced an irreversible concentration- and time-dependent (1-30 µg/mL) neuromuscular blockade, with 50% blockade occurring between 8 and 30 min. Muscle contractures evoked by exogenous acetylcholine were completely abolished by MLV, whereas those of KCl were also significantly altered (86% ± 11%, 53% ± 11%, 89% ± 5% and 89% ± 7% for one, three, 10 and 30 µg of venom/mL, respectively; n = 4; p < 0.

Pharmacological study of a new Asp49 phospholipase A(2) (Bbil-TX) isolated from Bothriopsis bilineata smargadina (forest viper) venom in vertebrate neuromuscular preparations.

The neuromuscular activity of Bbil-TX, a PLA2 with catalytic activity isolated from Bothriopsis bilineata smargadina venom, was examined in chick biventer cervicis (BC) and mouse phrenic nerve-diaphragm (PND) preparations. In BC preparations, Bbil-TX (0.5-10 μg/ml) caused time- and concentration-dependent blockade that was not reversed by washing; the times for 50% blockade were 87 ± 7, 41 ± 7 and 19 ± 2 min (mean ± SEM; n = 4-6) for 1, 5 and 10 μg/ml, respectively.

Biochemical, pharmacological, and structural characterization of new basic PLA2 Bbil-TX from Bothriopsis bilineata snake venom.

Bbil-TX, a PLA2, was purified from Bothriopsis bilineata snake venom after only one chromatographic step using RP-HPLC on μ-Bondapak C-18 column. A molecular mass of 14243.8 Da was confirmed by Q-Tof Ultima API ESI/MS (TOF MS mode) mass spectrometry.

Mipartoxin-I, a novel three-finger toxin, is the major neurotoxic component in the venom of the redtail coral snake Micrurus mipartitus (Elapidae).

The major venom component of Micrurus mipartitus, a coral snake distributed from Nicaragua to northern South America, was characterized biochemically and functionally. This protein, named mipartoxin-I, is a novel member of the three-finger toxin superfamily, presenting the characteristic cysteine signature and amino acid sequence length of the short-chain, type-I, α-neurotoxins. Nevertheless, it varies considerably from related toxins, with a sequence identity not higher than 70% in a multiple alignment of 67 proteins within this family.

Presynaptic action of Bothriopsis bilineata smargadina (forest viper) venom in vitro.

In this work, we examined the neuromuscular activity of Bothriopsis bilineata smargadina (forest viper) venom in vertebrate isolated nerve-muscle preparations. In chick biventer cervicis preparations the venom caused concentration-dependent (0.1-30 μg/ml) neuromuscular blockade that was not reversed by washing, with 50% blockade occurring in 15-90 min.

Effect of Mikania glomerata (Asteraceae) leaf extract combined with anti-venom serum on experimental Crotalus durissus (Squamata: Viperidae) envenomation in rats.

Crotalic envenomation represents the highest number of deaths when compared to other snakebite envenomations of medical interest. Crotalic venom has important characteristics such as neurotoxicity, myotoxicity, nephrotoxicity, and clotting and hemolytic action. We evaluated the clinical and laboratory aspects of Crotalus durissus terrificus experimental envenomation in Wistar rats treated with antivenom and the aqueous extract of the plant Mikania glomerata.