Is gender crucial for cardiovascular adjustments induced by exercise training in female spontaneously hypertensive rats?

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Acupuntura e implante de fragmentos de ouro em pontos de acupuntura e pontos Acupuntura e implante de fragmentos de ouro em pontos de acupuntura e pontos gatilho para o tratamento de displasia coxo-femoral em Pastor Alemão

Background: Canine hip dysplasia (HD) is characterized by hip joint laxity and subluxation. It is the most common cause of osteoarthritis in dogs, especially in larger breeds. Its management includes nutritional supplements, nonsteroidal anti-inflammatory drugs, physical therapy, acupuncture or surgical procedures. Implantation of gold beads in acupuncture points and trigger points around a joint has been used in the treatment of osteoarthritis in dogs for at least 30 years. Gold bead implants(GBI) acts as continuous acupuncture stimulation and trigger point treatment in canine HD with long lasting results. Electrophysiological investigations of trigger points reveal dysfunctional muscle spindles which indicate that the electrical activity of active loci arises from extrafusal motor endplates.Case: This is a report on the use of acupuncture and GBI for bilateral HD in a nine year old female German Shepherd. The patient has a HD non-responsive to anti-inflammatory drugs and was unable to stand up or walk by its own. Radiographs showed marked dysplasia, significant subluxation with the femoral head partly out of a shallow acetabulum and massive secondary arthritic bone changes, mainly on the right side. The animal was submitted to eight acupuncture sessions with seven days interval. After the first acupuncture session the use of NSAID was interrupted. After eight weeks the dog was considered rehabilitated and underwent GBI in acupoints and trigger points as maintenance treatment. During the one-year follow-up period the improvement remained unchanged with no need of analgesics.Discussion: It has been suggested that acupuncture or GBI can treat the chronic pain resulting from osteoarthritis induced by HD. According to AP theory, GBI is permanent and long-lasting acupoint stimulation. Moreover, the method is inexpensive, quick and easy to perform, with no postoperative pain or need of exercise restriction. Although gold is extremely corrosion-resistant, the surface of the gold implants stimulates a reaction from the immune system causing an oxidative liberation of gold ions with anti-inflammatory actions. It is well known that gold ions are effective inhibitors of the respiratory burst of neutrophils and monocytes and the proliferation of lymphocytes. These findings suggest that gold implantation, on a local scale, mimics the anti-inflammatory and pain-relieving effect of drugs with chemically bound gold ions. The relatively slow speed of the process results in a limited liberation of gold ions securing that they are taken up almost exclusively by cells close to the implant. The nine year old female German shepherd had a positive response to acupuncture with pain relieve and locomotor rehabilitation. For the nine year old female German shepherd previous acupuncture sessions to GBI resulted in no post-implant worsening period. Indeed, the association acupuncture/GBI does not have the anti-inflammatory drugs undesirable effects and brings long lasting results. In conclusion, GBI therefore should be considered for canine HD when conservative or medical treatments fail to give the desired effect.

Reinforcing properties of fencamfamine: Involvement of dopamine and opioid receptors

Fencamfamine (FCF) is a psychostimulant classified as an indirect dopamine agonist. The conditioning place preference (CPP) paradigm was used to investigate the reinforcing properties of FCF. After initial preferences had been determined, animals were conditioned with FCF (1.75, 3.5, or 7.0 mg/kg; IP). Only at the dose of 3.5 mg/kg FCF produced a significant place preference. Pretreatment with SCH23390 (0.05 mg/kg, SC) or naloxone (1.0 mg/kg SC) 10 min before FCF (3.5 mg/kg; IP) blocked both FCF-induced hyperactivity and CPP. Pretreatment with metoclopramide (10.0 mg/kg; IP) or pimozide (1.0 mg/kg, IP), respectively, 30 min or 4 h before FCF (3.5 mg/kg; IP), which blocked the FCF-induced locomotor activity, failed to influence place conditioning produced by FCF. In conclusion, the present study suggests that dopamine D 1 and opioid receptors are related to FCF reinforcing effect, while dopamine D 2 subtype receptor was ineffective in modifying FCF-induced CPP.

Espinha bífida e mielodisplasia em ruminantes: Relato de caso

Spina bifida with mielodysplasia are described in calf and lamb in this report. Locomotor abnormalities in the pelvic limbs and vertebral malformation were found in both animals, and arthrogryposis was also present in the calf. The mielodysplasia was very similar in these animals, and both were characterized by non separation of ventral and dorsal horns, areas with medular canal duplication and syringomyelia. No cases of spina bifida was previously described in Brazil.

Histoenzymology and morphometry of the masticatory muscles of tufted capuchin monkey (Cebus apella Linnaeus, 1758)

Samples of the anterior and posterior regions of the masseter and temporal muscles and of the anterior belly of the digastric muscle of 4 adult male tufted capuchin monkeys (Cebus apella) were removed and stained with HE and submitted to the m-ATPase reaction (with alkaline and acid preincubation) and to the NADH-TR and SDH reactions. The results of the histoenzymologic reactions were similar, except for acid reversal which did not occur in fibers of the fast glycolytic (FG) type in the mandibular locomotor muscles. FG fibers had a larger area and were more frequent in all regions studied. No significant differences in frequency or area of each fiber type were detected, considering the anterior and posterior regions of the masseter and temporal muscles. The frequency of fibers of the fast oxidative glycolytic (FOG) and slow oxidative (SO) types and of FOG area differed significantly between the anterior belly of the digastric muscle and the mandibular locomotor muscle. The predominance of fast twitch (FG and FOG) fibers and the multipenniform and bipenniform internal architecture of the masseter and temporal muscles, respectively, are characteristics that permit the powerful bite typical of tufted capuchin monkeys.

Envolvimento do sistema dopaminérgico na sensibilização comportamental ao femproporex

The effects of repeated administration of fenproporex (FEN) on motor activity of rats were studied. FEN-treated group (5.0 mg/kg, i.p., single dose, 7 consecutive days), showed a marked increase in the motor activity of rats, indicating that the drug induced behavioral sensitization. Repeated coadministration of haloperidol prevented the development of sensitization to repeated administration of FEN. Repeated administration of FEN increased also locomotor activity measured in the open field, ratifying the occurence of sensitization. These findings indicated development of sensitization to repeated FEN administration and that the dopamine system might be involved in the mechanism of sensitization.

Injeção epidural de cetamina ou cetamina levógira no controle da dor pós-incisional, em eqüinos

The aim of this study was to evaluate the pre-emptive effect of epidural ketamine S (+) (SK) or racemic ketamine (RK) administration, in post-incisional pain in horses. Were used in a blinded, randomized experimental study, sixteen mixed breed mares, 6±2 years old, weighting 273.2±42.0 kg. An epidural catheter was inserted 24 hours before the trials. The thigh region was shaved bilaterally, and mechanical cutaneous sensibility was measured using von Frey filaments (T-30). Using the left side as the control one, local anesthesia was performed at the right side. Twenty-five minutes later, SK was injected in G1 or RK in G2 through the epidural catheter. Five minutes after the ketamine injection, a 10 cm skin incision was made on the right side, and then sutured. Mechanical post-incisional pain was measured using von Frey filaments, at 1, 3 and 5 cm around the incision at 15 minutes intervals, for 2 hours, then 4, 6 and 8 hours after suturing. No changes were observed in the heart and respiratory rate and rectal temperature among groups or times of each group. Hind limb ataxia was observed in 62.5% and 12.5% of G1 and G2 respectively. SK and RK reduced cutaneous sensibility in the right and the left sides to mechanical postincisional pain during all time of experiment. Epidural SK and RK produce similar post-incisional analgesic effects, did not interfere in the cardio-respiratory parameters. The SK induces more intense ataxia in mares and presents a larger analgesic potency in the first 60 minutes after the administration.

Baseline and stress-induced plasma corticosterone concentrations of mice selectively bred for high voluntary wheel running

The hypothalamic-pituitary-adrenal (HPA) axis is important in regulating energy metabolism and in mediating responses to stressors, including increasing energy availability during physical exercise. In addition, glucocorticoids act directly on the central nervous system and influence behavior, including locomotor activity. To explore potential changes in the HPA axis as animals evolve higher voluntary activity levels, we characterized plasma corticosterone (CORT) concentrations and adrenal mass in four replicate lines of house mice that had been selectively bred for high voluntary wheel running (HR lines) for 34 generations and in four nonselected control (C) lines. We determined CORT concentrations under baseline conditions and immediately after exposure to a novel stressor (40 min of physical restraint) in mice that were housed without access to wheels. Resting daytime CORT concentrations were approximately twice as high in HR as in C mice for both sexes. Physical restraint increased CORT to similar concentrations in HR and C mice; consequently, the proportional response to restraint was smaller in HR than in C animals. Adrenal mass did not significantly differ between HR and C mice. Females had significantly higher baseline and postrestraint CORT concentrations and significantly larger adrenal glands than males in both HR and C lines. Replicate lines showed significant variation in body mass, length, baseline CORT concentrations, and postrestraint CORT concentrations in one or both sexes. Among lines, both body mass and length were significantly negatively correlated with baseline CORT concentrations, suggesting that CORT suppresses growth. Our results suggest that selection for increased locomotor activity has caused correlated changes in the HPA axis, resulting in higher baseline CORT concentrations and, possibly, reduced stress responsiveness and a lower growth rate. © 2007 by The University of Chicago. All rights reserved.

Experimental envenomation with Crotalus durissus terrificus venom in dogs treated with antiophidic serum - Part I: Clinical evaluation, hematology and myelogram

The present study aimed at evaluating clinical and laboratory aspects during experimental envenomation by Crotalus durissus terrificus in dogs treated with antiophidic serum. Twenty-one dogs were divided into three groups of seven animals each. Group I received 1mg/kg venom (sc); Group II received 1mg/kg venom (sc), 50mg antiophidic serum (iv), and fluid therapy including 0.9% NaCl solution (iv); and Group III received 1mg/kg venom (sc), 50mg antiophidic serum (iv), and fluid therapy including 0.9% NaCl solution containing sodium bicarbonate diluted to the dose of 4mEq/kg. The clinical signs of ataxia, sedation, flaccid paralysis, mydriasis, eyeball paralysis, mandible ptosis, sialorrhea, vomiting and diarrhea observed in the dogs were very similar to those observed in humans. The decrease in hemoglobin, hematocrit, erythrocyte, platelet and fibrinogen levels, prolongation of clotting time, prothrombin time (PT) and activated partial thromboplastin time (APTT), as well as hypocellularity in the bone marrow characterized anemia, thrombocytopenia and blood incoagulability, as well as hypofibrinogenemia and decreased bone-marrow activity. Important bleeding was not observed. Increased numbers of leukocytes and neutrophils and decreased numbers of lymphocytes and eosinophils characterized an acute inflammatory response and stress caused by generalized pain. The employed antiophidic serum was effective and all animals survived.

Comparação dos efeitos da romifidina e de uma emulsão de amitraz na sedação e na atividade locomotora espontânea de eqüinos

Amitraz (AM) and romifidine (RMF), two alpha-2 adrenoceptor agonists, produce sedative effect and decrease spontaneous locomotor activity (SLA) of horses. The behavioral effects and sedation after intravenous injection of RMF (0.06mg/kg) or AM 0.1mg/kg (AM 0.1) or AM 0.4mg/kg (AM 0.4) were compared in horses. RMF caused head ptosis (HP) until 45 min. The lower AM dose induced HP from 45 to 60 minutes and from 120 to 150 minutes, and the higher dose induced HP until 180 minutes. Data concerning changes in SLA were not conclusive. RMF or AM 0.4 caused a greater sedation than AM 0.1 until 20 min. After 20 minutes, the sedation caused by AM 0.4 was greater than that of RMF or AM 0.1. Romifidine caused consistent sedation until 45 minutes. The amitraz emulsion produced a dosedependent sedation until 180 minutes. Comparing to romifidine, the emulsion of amitraz induced a more substantial sedation. At dosages and dilution applied, amitraz is an effective sedative for horses.

Determination of broiler femur parameters at different growth phases

The objective of this experiment was to analyse macroscopically the femur and determine the biochemical values at 8, 22 and 42 days of age, producing basic results that can help to understand the pathogeny of the locomotor problems and the broiler physiologic growth. A total of 60 Cobb male broilers were distributed in three age groups (8, 22 and 42 days of age) of 20 birds. All macroscopic measurements, except the cranial compact layer increased (p<0.05) over the course of the ages. The cranial compact layer presented the biggest measure at 22 days of age. The ash percentage increased (p<0.05) until 22 days of age, but at 42 days of age this values decreased. Calcium and phosphorus percentage in ash increased (p<0.05) until 22 days of age and evidenced constancy from 22 to 42 days of age. The biomechanical adaptation capacity of femur was evidenced by the increase of the macroscopic measures over the course of the ages and the different behavior of cranial compact layer at 22 days of age suggested an adaptation attempt of the immature bone to muscle mass increase. The ash and mineral percentage confirmed that the relative growth occurs with more intensity until 21 days of age. The calcium and phosphorus percentage evidenced the physiologic balance acting on the deposition of these minerals in femur. © Asian Network for Scientific Information, 2011.

Alterações eletromiográficas e histopatológicas da musculatura de cães naturalmente infectados por Leishmania infantum

The aim of this study was to evaluate the electromyographic and histopathological changes in skeletal muscles of dogs naturally infected by L. infantum. Twenty five mixed breed adult dogs with parasitological, molecular and serological diagnosis were selected. The evaluated muscles were: triceps brachial, extensor carpi radialis, biceps femoris and gastrocnemius. One dog had locomotor clinical signs with hind limbs paresis associated with severe muscle atrophy. Twenty-three (92%) had some type of muscular change, and in 22 (88%) such changes were directly identified by electromyography. Even without any clinical signs of the disease, 10 (40%) dogs had electromyographic and histopathological changes. Leishmania antigens were detected in muscles of four (16%) dogs. The electromyographic evaluation indicated the occurrence of chronic polymyositis in 13 (52%) dogs, the presence of both acute and chronic muscle inflammation four (16%), acute myopathy in two (8%) and absence of electromyographic abnormalities in three (12%) dogs. The most frequently observed histopathological changes were degeneration and necrosis of myofibers and inflammatory infiltration observed in 12 (48%) dogs. Other changes were decreased diameter of muscle fibers in 15 (60%) and peri or endomysial fibrosis in 14 (56%) animals. The changes observed in the present study showed that even in the absence of clinical signs, most dogs infected by Leishmania infantum have chronic polymyositis.

Citrus aurantium L. essential oil exhibits anxiolytic-like activity mediated by 5-HT1A-receptors and reduces cholesterol after repeated oral treatment

Background: The current treatments for anxiety disorders and depression have multiple adverse effects in addition to a delayed onset of action, which has prompted efforts to find new substances with potential activity in these disorders. Citrus aurantium was chosen based on ethnopharmacological data because traditional medicine refers to the Citrus genus as useful in diminishing the symptoms of anxiety or insomnia, and C. aurantium has more recently been proposed as an adjuvant for antidepressants. In the present work, we investigated the biological activity underlying the anxiolytic and antidepressant effects of C. aurantium essential oil (EO), the putative mechanism of the anxiolytic-like effect, and the neurochemical changes in specific brain structures of mice after acute treatment. We also monitored the mice for possible signs of toxicity after a 14-day treatment.Methods: The anxiolytic-like activity of the EO was investigated in a light/dark box, and the antidepressant activity was investigated in a forced swim test. Flumazenil, a competitive antagonist of benzodiazepine binding, and the selective 5-HT1A receptor antagonist WAY100635 were used in the experimental procedures to determine the mechanism of action of the EO. To exclude false positive results due to motor impairment, the mice were submitted to the rotarod test.Results: The data suggest that the anxiolytic-like activity observed in the light/dark box procedure after acute (5 mg/kg) or 14-day repeated (1 mg/kg/day) dosing was mediated by the serotonergic system (5-HT1A receptors). Acute treatment with the EO showed no activity in the forced swim test, which is sensitive to antidepressants. A neurochemical evaluation showed no alterations in neurotransmitter levels in the cortex, the striatum, the pons, and the hypothalamus. Furthermore, no locomotor impairment or signs of toxicity or biochemical changes, except a reduction in cholesterol levels, were observed after treatment with the EO.Conclusion: This work contributes to a better understanding of the biological activity of C. aurantium EO by characterizing the mechanism of action underlying its anxiolytic-like activity. © 2013 Costa et al; licensee BioMed Central Ltd.

Intravenous Tramadol Injection has no Antinociceptive Effect in Horses Undergoing Electrical and Thermal Stimuli

Tramadol combines an μ opiate and nonopiate analgesic mechanism and might be a useful opioid in horses. This study evaluated the effect of IV tramadol on spontaneous locomotor activity (SLA), head height, and hoof withdrawal reflex (HWR) after thermal or electrical nociceptive stimuli in horses. Doses of 2 and 3 mg/kg tramadol did not affect HWR after electrical and thermal nociception, respectively. Head height and SLA were not modified by 2, 3, or 5 mg/kg tramadol. All horses treated with 5 mg/kg tramadol developed trembling in pectoral triceps, and gluteal muscles and adopted a base-wide stance. In conclusion, 2 and 3 mg/kg tramadol IV neither induced sedation nor prolonged HWR after thermal or electrical stimuli in conscious horses. The dose of 5 mg/kg tramadol IV produced excitement, and it is apparently unsuitable for clinical use. © 2013 Elsevier Inc. All rights reserved.

Ethopharmacological evaluation of the rat exposure test: A prey-predator interaction test

The rat exposure test (RET) is a prey (mouse)-predator (rat) situation that activates brain defensive areas and elicits hormonal and defensive behavior in the mouse. Here, we investigated possible correlations between the spatiotemporal [time spent in protected (home chamber and tunnel) and unprotected (surface) compartments and frequency of entries into the three compartments] and ethological [e.g., duration of protected and unprotected stretched-attend postures (SAP), duration of contact with the rat's compartment] measures (Experiment 1). Secondly, we investigated the effects of systemic treatment with pro- or anti-aversive drugs on the behavior that emerged from the factor analysis (Experiment 2). The effects of chronic (21 days) imipramine and fluoxetine on defensive behavior were also investigated (Experiment 3). Exp. 1 revealed that the time in the protected compartment, protected SAP and rat contacts loaded on factor 1 (defensive behavior), while the total entries and unprotected SAP loaded on factor 2 (locomotor activity). Exp. 2 showed that alprazolam (but not diazepam) selectively changed the defensive factor. Caffeine produced a mild proaversive-like effect, whereas yohimbine only decreased locomotor activity (total entries). Fluoxetine (but not imipramine) produced a weak proaversive-like effect. 5-HT1A/5-HT2 receptor ligands did not change any behavioral measure. In Exp. 3, chronic fluoxetine (but not imipramine) attenuated the defensive behavior factor without changing locomotion. Given that the defensive factor was sensitive to drugs known to attenuate (alprazolam and chronic fluoxetine) and induce (caffeine) panic attack, we suggest the RET as a useful test to assess the effects of panicolytic and panicogenic drugs. © 2012 Elsevier B.V.