RESUMO
Horses are outstanding athletes, performing in many different disciplines involving different kinds of efforts and metabolic responses. Depending on exercise intensity, their skeletal muscle oxygenation decreases, and the reperfusion at cessation of the exercise can cause excessive production of free radicals. This study on cultured primary equine myoblasts investigated the effect of different kinds of anoxia/reoxygenation (A/R) on routine respiration, mitochondrial complex I specific activity and free radicals production. Our data revealed that short cycles of A/R caused a decrease of all the parameters, opposite to what a single long period of anoxia did. A preconditioning-like effect could explain our first pattern of results whereas mild uncoupling could be more appropriate for the second one. Anyway, it seems that mitochondrial complex I could play a major role in the regulation of the balance between metabolic and antioxidant protection of the muscular function of athletic horses.
Assuntos
Radicais Livres/metabolismo , Mitocôndrias Musculares/metabolismo , Mioblastos/metabolismo , Trifosfato de Adenosina/metabolismo , Animais , Células Cultivadas , Cavalos , Hipóxia/metabolismo , Canais Iônicos/metabolismo , Mitocôndrias Musculares/fisiologia , Proteínas Mitocondriais/metabolismo , Mioblastos/fisiologia , Oxigênio/metabolismo , Proteína Desacopladora 3RESUMO
Horses are particularly sensitive and exposed to excessive inflammatory responses evolving toward an important stimulation of polymorphonuclear neutrophils (PMNs). The aim of this work was to stimulate equine neutrophils in whole blood and to evaluate their response by measuring the release of total and active myeloperoxidase (MPO) and total elastase, considered as markers of neutrophil stimulation and degranulation. Because of the critical importance of the concomitant presence of LPS and TNF-α in equine pathological situations, we combined these two natural mediators to stimulate PMN and compared the response with those obtained after the PMN stimulation with each mediator used alone and well-known artificial stimulation systems such as 12-phorbol 13-myristate acetate (PMA) and the combination of cytochalasin B (CB) and N-formyl-methionyl-leucyl-phenylalanine (fMLP). All the activation systems, PMA, CB/fMLP, TNF-α, LPS and LPS/TNF-α, induced a significant release of total MPO in whole blood but only the combinations CB/fMLP and LPS/TNF-α significantly favored the release of active MPO. Regarding the total elastase, we did not observe a significant release in all the stimulated conditions except with PMA. It appears clearly that the choice of the neutrophil stimulation model is fundamental for the selection of potentially active pharmacological agents, especially on MPO activity.
Assuntos
Cavalos/sangue , Neutrófilos/metabolismo , Elastase Pancreática/metabolismo , Peroxidase/metabolismo , Animais , Biomarcadores , Regulação Enzimológica da Expressão Gênica , Lipopolissacarídeos/metabolismo , Modelos Biológicos , Elastase Pancreática/genética , Peroxidase/genética , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/metabolismoRESUMO
In the human and equine species, different kinds of free floating intra-articular particles are related to certain disorders. Osteochondral fragments formed during osteochondrosis dissecans are the most common finding in the equine species, whereas in humans rice bodies due to rheumatoid arthritis are more frequent. Herein we report a third type of floating body inside the stifle of an adult draught horse stallion, in macroscopic appearance similar to articular rice bodies known in humans. As revealed by histologic examination, the two particles consist of polypoid degenerated structures derived from synovial villi. Their formation was probably induced by ischemia.