Uticaj dodavanja zeolita na kvalitet mesa pastrmke

U radu je ispitivan uticaj zeolita tipa "Minazel" kao aditiva hrane za pastrmke primenjenog u koncentraciji od 1% i 2% na sledeće proizvodne parametre: osnovni hemijski sastav mesa, mikotoksikološku ispravnost, senzorne osobine, randman i koncentraciju pojedinih makro i mikroelemenata. Primenjene koncentracije zeolita, kao aditiva hrane nisu uticale na hemijski sastav pastrmskog mesa, koncentraciju minerala (Ca, Cu, Zn, Pb i Mn) i njegove senzorne osobine. Izvesni stepen pozitivnog uticaja ispoljen je u pogledu randmana mesa i prosečne telesne mase pastrmki posle ezenteracije

Potrebe u proteinima u ishrani mlađi šarana

Protein level and quality are of utmost important to growth of fish. Although common carp is a popular experimental fish, contradictory results on protein requirement have been reported by different works. An experiment lasting for 3 months included different protein level in 4 diets: 38.1%, 38.5%, 41.5% and 43.7%. Carp yearlings (body mass 95.5g) were fed in order to investigate effects on growth rate. There were no significant differences in the final individual weights, weight gains, specific growth rates (SGR), feed conversion rate (FCR) and thermal growth coefficient (TGC) among fish fed different diets (P>0.05)

HIF-1 alpha response to hypoxia is functionally separated from the glucocorticoid stress response in the in vitro regenerating human skeletal muscle

Pirkmajer S, Filipovic D, Mars T, Mis K, Grubic Z. HIF-1 alpha response to hypoxia is functionally separated from the glucocorticoid stress response in the in vitro regenerating human skeletal muscle. Am J Physiol Regul Integr Comp Physiol 299: R1693-R1700, 2010. First published October 13, 2010; doi:10.1152/ajpregu.00133.2010.-Injury of skeletal muscle is followed by muscle regeneration in which new muscle tissue is formed from the proliferating mononuclear myoblasts, and by systemic response to stress that exposes proliferating myoblasts to increased glucocorticoid (GC) concentration. Because of its various causes, hypoxia is a frequent condition affecting skeletal muscle, and therefore both processes, which importantly determine the outcome of the injury, often proceed under hypoxic conditions. It is therefore important to identify and characterize in proliferating human myoblasts: 1) response to hypoxia which is generally organized by hypoxia-inducible factor-1 alpha (HIF-1 alpha); 2) response to GCs which is mediated through the isoforms of glucocorticoid receptors (GRs) and 11 beta-hydroxysteroid dehydrogenases (11 beta-HSDs), and 3) the response to GCs under the hypoxic conditions and the influence of this combination on the factors controlling myoblast proliferation. Using real-time PCR, Western blotting, and HIF-1 alpha small-interfering RNA silencing, we demonstrated that cultured human myoblasts possess both, the HIF-1 alpha-based response to hypoxia, and the GC response system composed of GR alpha and types 1 and 2 11 beta-HSDs. However, using combined dexamethasone and hypoxia treatments, we demonstrated that these two systems operate practically without mutual interactions. A seemingly surprising separation of the two systems that both organize response to hypoxic stress can be explained on the evolutionary basis: the phylogenetically older HIF-1 alpha response is a protection at the cellular level, whereas the GC stress response protects the organism as a whole. This necessitates actions, like downregulation of IL-6 secretion and vascular endothelial growth factor, that might not be of direct benefit for the affected myoblasts

In Vitro Innervation as an Experimental Model to Study the Expression and Functions of Acetylcholinesterase and Agrin in Human Skeletal Muscle

Acetylcholinesterase (AChE) and agrin, a heparan-sulfate proteoglycan, reside in the basal lamina of the neuromuscular junction (NMJ) and play key roles in cholinergic transmission and synaptogenesis. Unlike most NMJ components, AChE and agrin are expressed in skeletal muscle and α-motor neurons. AChE and agrin are also expressed in various other types of cells, where they have important alternative functions that are not related to their classical roles in NMJ. In this review, we first focus on co-cultures of embryonic rat spinal cord explants with human skeletal muscle cells as an experimental model to study functional innervation in vitro. We describe how this heterologous rat-human model, which enables experimentation on highly developed contracting human myotubes, offers unique opportunities for AChE and agrin research. We then highlight innovative approaches that were used to address salient questions regarding expression and alternative functions of AChE and agrin in developing human skeletal muscle. Results obtained in co-cultures are compared with those obtained in other models in the context of general advances in the field of AChE and agrin neurobiology

Abstracts

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