RESUMO
We evaluated the effects of a substrate in the biosynthesis of nitric oxide (NO)-l-arginine (LARG)-on hepatic lesions caused by ischemia/reperfusion (I/R) injury in rabbit livers. Rabbits were pretreated with LARG (150 mg/kg IV) or saline solution 0.9% (SS) before the hepatic I/R procedure. The effects of LARG on hepatic injury were evaluated before and after I/R. The warm hepatic I/R procedure produced profound acute liver injury, as indicated by elevated values of serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), and lactic dehydrogenase (LDH), as well as a high apoptotic cell count. All changes were attenuated by treatment with LARG before the hepatic I/R procedure. These results suggested that LARG produced protective effects on hepatic I/R lesions. This protective effect of LARG was probably associated with blocking generation of superoxide anions during the hepatic I/R procedure.
Assuntos
Arginina/uso terapêutico , Hepatopatias/prevenção & controle , Traumatismo por Reperfusão/prevenção & controle , Alanina Transaminase/sangue , Alanina Transaminase/efeitos dos fármacos , Animais , Aspartato Aminotransferases/sangue , Aspartato Aminotransferases/efeitos dos fármacos , L-Lactato Desidrogenase/sangue , L-Lactato Desidrogenase/efeitos dos fármacos , Circulação Hepática/efeitos dos fármacos , Masculino , Óxido Nítrico/metabolismo , Coelhos , Traumatismo por Reperfusão/enzimologia , Traumatismo por Reperfusão/patologia , Vasoconstrição/efeitos dos fármacosRESUMO
Immunohistochemistry was used to verify whether choline-acetiltransferase colocalizes with calcium-binding proteins and NMDA receptor subunit NR1 in the rat retina. Whereas calbindin and parvalbumin were not observed in cholinergic amacrine cells, calretinin and NR1 were very frequently colocalized with ChAT. Calretinin/NR1-positive cells were also shown, suggesting that calretinin in cholinergic cells of the rat may be related to the buffering of excess intracellular calcium generated by activation of NMDA receptors.
Assuntos
Acetilcolina/metabolismo , Neurônios/citologia , Neurônios/metabolismo , Receptores de N-Metil-D-Aspartato/metabolismo , Retina/citologia , Retina/metabolismo , Proteína G de Ligação ao Cálcio S100/metabolismo , Animais , Calbindina 2 , Calbindinas , Colina O-Acetiltransferase/metabolismo , Parvalbuminas/metabolismo , Ratos , Ratos WistarRESUMO
Immunohistochemical techniques reveal that the dopamine- and cAMP-regulated phosphoprotein DARPP-32 is detectable in neurons of the chick optic tectum starting on embryonic day 13. The expression levels then increase steadily from embryonic day 15 through the first posthatching day. After 15 days posthatching, expression of DARPP-32 reaches the adult pattern, with many labeled cells in tectal layers 11 and 12. These cells exhibit a bipolar shape, with long processes directed both to the deep and superficial layers. These results suggest that DARPP-32 is present in specific neuronal populations of the chick tectum and that this protein may not have a function in early ontogenetic processes.
Assuntos
Proteínas do Tecido Nervoso/metabolismo , Fosfoproteínas/metabolismo , Colículos Superiores/metabolismo , Animais , Embrião de Galinha , Galinhas , Fosfoproteína 32 Regulada por cAMP e Dopamina , Colículos Superiores/embriologia , Colículos Superiores/crescimento & desenvolvimentoRESUMO
Fos immunohistochemistry was used to characterize neurons in the chick retina activated by optokinetic and stationary stimuli. Higher percentages of co-localization of Fos and the alpha5 subunit of the nicotinic acetylcholine receptor, and Fos and GABA were observed in retinal neurons after optokinetic compared to the stationary stimulation. These results indicate an involvement of the cholinergic and GABAergic circuitries in the motion detection by chick retinal cells.
Assuntos
Percepção de Movimento/fisiologia , Proteínas do Tecido Nervoso/análise , Neurônios/metabolismo , Proteínas Proto-Oncogênicas c-fos/análise , Retina/metabolismo , Acetilcolina/fisiologia , Animais , Galinhas , Imuno-Histoquímica , Retina/citologia , Ácido gama-Aminobutírico/fisiologiaRESUMO
Immunohistochemistry was used to examine the co-occurrence of nicotinic acetylcholine receptor subunits with calcium-binding proteins in ganglion cells of the chick retina. The alpha3 subunit was rarely observed in ganglion cells containing calbindin, calretinin, or parvalbumin. On the other hand, the alpha8 subunit was more often co-localized with all calcium-binding proteins studied. These results may be related to the high calcium permeability of nicotinic receptors that contain the alpha8 subunit.
Assuntos
Proteínas de Ligação ao Cálcio/metabolismo , Receptores Nicotínicos/metabolismo , Células Ganglionares da Retina/metabolismo , Animais , Animais Recém-Nascidos , Calbindina 2 , Calbindinas , Galinhas , Parvalbuminas/metabolismo , Proteína G de Ligação ao Cálcio S100/metabolismo , Distribuição TecidualRESUMO
The Fos protein was immunocytochemically detected in the chick ventral lateral geniculate nucleus after novel stationary and optokinetic stimulation. Fos-positive nuclei were mainly detected in the internal part of the ventral geniculate when the animals were submitted to stationary visual stimulation. On the other hand, Fos-positive nuclei were mainly seen in the external part of the nucleus when optokinetic stimuli were used. These data reveal functional subdivisions of the avian ventral geniculate, and support the hypothesis that this nucleus is involved in several aspects of the visual function.