330 research outputs found
Osteopathic Manipulative Treatment and Cardiovascular Autonomic Parameters in Rugby Players: A Randomized, Sham-Controlled Trial
Objective: The purpose of this study was to investigate the effects of osteopathic manipulative treatment (OMT) on cardiovascular autonomic parameters after a rugby match. Methods: Resting and reactivity (ie, response to orthostasis) measures of mean arterial pressure, heart rate, and heart rate variability were assessed in 23 male players after a single session of OMT, both 18 to 20 hours after a rugby match and in a corresponding no-match condition, in a randomized, sham-controlled, crossover design. Results: Signs of reduced heart rate variability and elevated mean arterial pressure and heart rate were found 18 to 20 hours after a rugby match compared with the no-match condition. A significant increase in heart rate variability and a significant reduction in mean arterial pressure were observed after OMT in both the after-match and no-match conditions. Heart rate and heart rate variability responses to orthostasis were not affected by previous match competition, but were significantly larger after OMT compared with sham treatment. Conclusion: This study suggests the presence of cardiovascular autonomic alterations in rugby players after a competitive match, which may be indicative of prolonged fatigue and incomplete recovery. In these players, favorable changes in cardiovascular autonomic parameters were observed following a single session of OMT
Effects of Administration of Three Different By-Pass Lipids on Growth Performance, Rumen Activity and Feeding Behaviour of Beef Cattle
A study was carried out on beef cattle to compare three different by-pass lipids administration in relation to their intake, performance, bunk behaviour and rumen fermentation characteristics. Ninety-six Charolaise males were subdivided into three groups. Each group was fed a specific diet including differentiated sources of rumen by-pass fats. The first group received 500 g/head/day of calcium salts (CaS), the second and the third received 420 g/head/day of hydrogenated fatty acids (HF) and triglycerides (AL), respectively. The three by-pass fats differ in fatty acids composition, chain length and mean particle size. AL group had average daily gain significantly greater (P = 0.0005) than animals fed calcium soaps. No difference was observed between AL and HF groups (P = 0.08) and between HF and CaS groups. Final body weights of AL animals were significantly higher (P = 0.005) than CaS group. There were no differences between AL group and HF group and between HF group and CaS group. Average dry matter intake (DMI) was higher (P < 0.05) in AL and HF groups compared with CaS group. Feed conversion rate was better for AL and CaS groups (P<0.05) compared with HF group. Evaluating their behaviours in approaching feed, the animals seemed to prefer hydrogenated fats flavour as regard to calcium soaps. No differences were highlighted in ruminal pH and ruminal volatile fatty acids composition among the three groups. When high dosage of fat is included into a beef cattle diet, the administration of hydrogenated triglycerides, characterized by a pleasant flavour and a small mean particle size, is likely to prove more suitable than adding calcium soaps or hydrogenated free fatty acids, probably thanks to its higher DMI and feed conversion rate, respectively. With regard to the latter higher rate, it could be only supposed that it is related to the smaller mean particle size of hydrogenated triglycerides
Replacing sodium bicarbonate with half amount of calcareous marine algae in the diet of beef cattle
This study evaluated the effects of feeding calcareous marine algae or sodium bicarbonate as rumen buffer on the performance, behaviour, in vitro diet digestibility, and meat quality of beef cattle. A total of 180 Charolaise bullocks (536-38 kg; 14-1 months of age) were divided into two homogeneous groups and fed a diet with a mineral mix containing 40% sodium bicarbonate or 20% calcareous marine algae (CMA) for the entire fattening period (130 days). Of the in vivo and in vitro parameters evaluated, CMA supplementation improved average daily gain and feed conversion ratio and reduced the prevalence of bloat and lameness. Bullocks fed CMA tended to exhibit a calmer behaviour while in the pen. Supplementation with CMA improved rumen pH and in vitro digestion. Meat from bullocks fed CMA showed a lower pH and higher lightness and tenderness. The results suggest that CMA is more effective than sodium bicarbonate in buffering beef cattle, with a positive impact on growth performance, feed efficiency, health, and meat quality
Antidepressant-like effects of pharmacological inhibition of FAAH activity in socially isolated female rats
Pharmacological inhibition of the enzyme fatty acid amide hydrolase (FAAH), which terminates signaling of the endocannabinoid N-arachidonoylethanolamine (or anandamide, AEA), exerts favourable effects in rodent models of stress-related depression. Yet although depression seems to be more common among women than men and in spite of some evidence of sex differences in treatment efficacy, preclinical development of FAAH inhibitors for the pharmacotherapy of stress-related depression has been predominantly conducted in male animals. Here, adult female rats were exposed to six weeks of social isolation and, starting from the second week, treated with the FAAH inhibitor URB694 (0.3 mg/kg/day, i.p.) or vehicle. Compared to pair-housed females, socially isolated female rats treated with vehicle developed behavioral (mild anhedonia, passive stress coping) and physiological (reduced body weight gain, elevated plasma corticosterone levels) alterations. Moreover, prolonged social isolation provoked a reduction in brain-derived neurotrophic factor (BDNF) and AEA levels within the hippocampus. Together, these changes are indicative of an increased risk of developing a depressive-like state. Conversely, pharmacological inhibition of FAAH activity with URB694 restored both AEA and BDNF levels within the hippocampus of socially isolated rats and prevented the development of behavioral and physiological alterations. These results suggest a potential interplay between AEA-mediated signaling and hippocampal BDNF in the pathogenesis of depression-relevant behaviors and physiological alterations and antidepressant action of FAAH inhibition in socially isolated female rats
Individual differences in plasma catecholamine and corticosterone stress responses of wild-type rats:Relationship with aggression
Plasma noradrenaline (NA), adrenaline (A), and corticosterone (CS) responses to social and nonsocial stressors were studied in male members of a strain of wild-type rats, widely differing in their level of aggression. The aggressiveness was preliminarily established by measuring the latency time to attack (ALT) a male intruder in a standard resident-intruder test. Animals were then provided with a jugular vein cannula for blood sampling during stress exposure. Implanted rats were randomly assigned to 3 experimental treatments: social stress (defeat experience, SD), nonsocial stress (presentation of a shock-prod, SP) and control (animals undisturbed in their home cages, CTR). A significant correlation was found between ALT and the amount of time spent in burying the probe in SP rats: the more aggressive the animal, the higher the rate of burying behavior. SD induced a much stronger effect on plasma NA, A, and CS concentrations than SP. A significant negative correlation was found between ALT scores and values of the area under the response time curve for NA and A, in both SD and SP situations: the more aggressive the animal the higher the catecholaminergic reactivity to the stressors. On the contrary, no evidence of a correlation between aggressiveness and plasma corticosterone responses was found neither in SD nor in SP rats. These findings in an unselected strain of wild-type rats confirmed that an aggressive/active coping strategy is associated with a high sympathetic-adrenomedullary activation and support the concept of individual differentiation in coping styles as a coherent set of behavioral and neuroendocrine characteristics. Copyright (C) 1996 Elsevier Science Inc
Elevated miR-34a expression and altered transcriptional profile are associated with adverse electromechanical remodeling in the heart of male rats exposed to social stress
This study investigated epigenetic risk factors that may contribute to stress-related cardiac disease in a rodent model. Experiment 1 was designed to evaluate the expression of microRNA-34a (miR-34a), a known modulator of both stress responses and cardiac pathophysiology, in the heart of male adult rats exposed to a single or repeated episodes of social defeat stress. Moreover, RNA sequencing was conducted to identify transcriptomic profile changes in the heart of repeatedly stressed rats. Experiment 2 was designed to assess cardiac electromechanical changes induced by repeated social defeat stress that may predispose rats to cardiac dysfunction. Results indicated a larger cardiac miR-34a expression after repeated social defeat stress compared to a control condition. This molecular modification was associated with increased vulnerability to pharmacologically induced arrhythmias and signs of systolic left ventricular dysfunction. Gene expression analysis identified clusters of differentially expressed genes in the heart of repeatedly stressed rats that are mainly associated with morphological and functional properties of the mitochondria and may be directly regulated by miR-34a. These results suggest the presence of an association between miR-34a overexpression and signs of adverse electromechanical remodeling in the heart of rats exposed to repeated social defeat stress, and point to compromised mitochondria efficiency as a potential mediator of this link. This rat model may provide a useful tool for investigating the causal relationship between miR-34a expression, mitochondrial (dys)function, and cardiac alterations under stressful conditions, which could have important implications in the context of stress-related cardiac disease
Bifidobacterium adolescentis as a key member of the human gut microbiota in the production of GABA
Gamma aminobutyric acid (GABA) is the principal inhibitory neurotransmitter playing a key role in anxiety and depression disorders in mammals. Recent studies revealed that members of the gut microbiota are able to produce GABA modulating the gut–brain axis response. Among members of the human gut microbiota, bifidobacteria are well known to establish many metabolic and physiologic interactions with the host. In this study, we performed genome analyses of more than 1,000 bifidobacterial strains publicly available revealing that Bifidobacterium adolescentis taxon might represent a model GABA producer in human gastrointestinal tract. Moreover, the in silico screening of human/animal metagenomic datasets showed an intriguing association/correlation between B. adolescentis load and mental disorders such as depression and anxiety. Interestingly, in vitro screening of 82 B. adolescentis strains allowed identifying two high GABA producers, i.e. B. adolescentis PRL2019 and B. adolescentis HD17T2H, which were employed in an in vivo trial in rats. Feeding Groningen rats with a supplementation of B. adolescentis strains, confirmed the ability of these microorganisms to stimulate the in vivo production of GABA highlighting their potential implication in gut–brain axis interactions
High carbon dioxide tension (PCO2) and the incidence of cardiac arrhythmias in rapidly growing broiler chickens
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