The purpose of the present study was to evaluate the possible effect of melanin-concentrating hormone (MCH) on learning and memory by using the one-trial step-down inhibitory avoidance test in rats. ...The peptide was infused into hippocampus, amygdala, and entorhinal cortex. MCH caused retrograde facilitation when given at 0 or 4 h post-training into hippocampus, but only at 0 h into amygdala. From these results, it seems that MCH modulates memory early after training by acting on both the amygdala and hippocampus and, 4 h after training, on the hippocampus.
Huperzia saururus is reported in Argentinean popular medicine as a memory improver. Chemical studies have shown that the main constituents of the species are
Lycopodium alkaloids. On the basis of ...this information, a purified alkaloid extract was obtained by alkaline extraction of the aerial parts. The aim of this work was to investigate the effects of intra-hippocampal administration of the purified alkaloid extract (AE) on memory retention in vivo, using a step down test, in order to correlate with previous results obtained in vitro in an electrophysiological model. The AE administration significantly increased the latency time in comparison to control animals. For treated animals the latency time was 37.61
±
2.84, 80.94
±
2.37, and 180.00
±
5.74
s for 1, 5, and 10
ng/rat, respectively versus 14.89
±
2.38
s for controls. According to these results there is a good relationship between the ethnopharmacological use and the effects hereby showed.
Highlights • Sauroxine is an alkaloid from Phlegmariurus saururus. • It inhibited the hippocampal long-term potentiation when was tested in vitro. • Sauroxine also impaired memory retention in ...Step-down test. • This alkaloid crossed the blood-brain barrier reaching the brain. • Sauroxine could be a potential therapeutic amnesic agent.
The present study describes the effects of sauroine (1), the main alkaloid obtained from Huperzia saururus, on memory retention and learning. To evaluate this, electrophysiological experiments and ...behavioral tests (step down) were performed on male Wistar rats. The results showed that 1 improved memory retention in the step-down test, significantly increasing hippocampal plasticity. Thus, 1 seems to be a constituent responsible for the activity claimed in folk medicine for H. saururus in Argentina.
Under the name of Creole goats, individuals of various origins, morphological and productivity characters are grouped. To characterize the genetic pool of goats from different sources in central ...Argentina, protein polymorphism revealed by electrophoresis was analyzed. A total of 109 adult animals from Santa Marı́a, Colón and Ischilı́n Districts, Córdoba Province, were studied. The red cells lysates were subjected to starch gel electrophoresis and specific staining procedures to reveal the activity of different enzymes and hemoglobin. Separation of plasmatic proteins was carried out by electrophoresis in polyacrylamide gel and stained with Coomassie Blue. From a total of 14 loci analyzed, eight were polymorphic in at least one flock. Four codominant alleles were detected in the locus βHemoglobin (βHb); three alleles in malic enzyme (Me), glucose 6 phosphate dehydrogenase (G6pdh) and lactate dehydrogenase (Ldh) and two alleles in catalase (Cat), transferrin (Tf), esterase-2 (Es-2) and phosphoglucomutase (Pgm). In all the cases, the observed genotype frequencies were not significantly different from those expected from Hardy–Weinberg equilibrium. The proportion of polymorphic loci (
P%) varied between 21.4% and 42.9% and mean heterozygosity (
H), between 0.061 and 0.117. Alleles at loci Cat, Me and Es-2 showed significantly different frequencies according to the sample origin. The flock from Colón District presented the highest levels of polymorphism. This is the only stock which includes hybrids of varying grade between Creole stocks and male specimens from Saanen and Nubian breeds.
The tricyclic anti-calmodulin drug trifluoperazine (TFP) inhibited growth and motility of epimastigotes of Trypanosoma cruzi, at concentrations lower than 100 microM, and motility and infectivity of ...the bloodstream trypomastigote form at 200 microM. Electron microscopy of TFP-treated epimastigotes showed that the major effect was at the mitochondrial level, with gross swelling and disorganization. The oligomycin-sensitive, mitochondrial ATPase was completely inhibited by 20 microM TFP, and the same drug concentration caused a 60% decrease in intracellular ATP content. The results suggest that the trypanocidal effect of TFP may be related more to mitochondrial damage than to the well-known anticalmodulin effect of the drug.
The scope of this study was to investigate possible relationships between He-Neon laser radiation and mitotic and phase indices in meristematic cells of Allium cepa L. bulbs. Our results indicate ...that mitotic index increased after irradiation depending this modification on the time exposure and the potency of the He-Neon beam. Phase indices were also modified: frequency of prophase increased, while inter- meta- and anaphase decreased: telophases remain unchanged. These variations were significative only when the preparations were irradiated a) with 5 mW for 10 min. or more, b) with 10 mW or c) when the preparations were processed 60 min. after irradiation. These findings could not be attributed to thermal changes. Modifications in RNA or protein synthesis could be responsible.
PDF
