Ovariectomy impairs spatial memory: prevention and reversal by a soy isoflavone diet.

Since a previous study has shown that ovariectomy impairs spatial memory, we, herein, investigate the influence of pre- and post-treatment with a soy diet on the effects elicited by ovariectomy on spatial memory. In the pre-treatment, 20-day-old female Wistar rats were first fed for 60 days on a standard diet with casein (control) or a soy diet. At 80 days of age, the animals were assigned to one of the following groups: sham (submitted to surgery without removal of ovaries) and ovariectomized.

Hypermethioninemia increases cerebral acetylcholinesterase activity and impairs memory in rats.

In the present study we investigated the effect of chronic hypermethioninemia on rat performance in the Morris water maze task, as well as on acetylcholinesterase (AChE) activity in rat cerebral cortex. For chronic treatment, rats received subcutaneous injections of methionine (1.34-2.

Supplementation with vitamins E plus C or soy isoflavones in ovariectomized rats: effect on the activities of Na(+), K (+)-ATPase and cholinesterases.

Since a previous study demonstrated that ovariectomized rats present an activation of Na(+), K(+)-ATPase and acetylcholinesterase (AChE) activities, in the present study we investigated the influence of vitamins E plus C or soy isoflavones on the effects elicited by ovariectomy on the activities of these enzyme in hippocampus of ovariectomized rats. We also determined the effect of the same compounds on the reduction of serum butyrylcholinesterase (BuChE) activity caused by ovariectomy. Female adult Wistar rats were assigned to one of the following groups: sham (submitted to surgery without removal of the ovaries) and ovariectomized.

alpha-Tocopherol and ascorbic acid prevent memory deficits provoked by chronic hyperprolinemia in rats.

In the present study we investigated the action of alpha-tocopherol and ascorbic acid on the effects elicited by chronic hyperprolinemia on rat performance in the Morris water maze. Rats received subcutaneous injections of proline (experimental group) twice a day, with 10 h-interval, from the 6 to 28th days of age or an equivalent volume of 0.9% saline solution (controls).

Vitamins E and C pretreatment prevents ovariectomy-induced memory deficits in water maze.

We investigated whether the pretreatment with vitamins E (alpha-tocopherol) and C (ascorbic acid) would act on ovariectomy-induced memory deficits in Morris water maze tasks. Adult female Wistar rats were divided into three groups: (1) naive (control), (2) sham (submitted to surgery without removal of ovaries) and (3) ovariectomized. Thirty days after surgery, they were trained in the Morris water maze in order to verify ovariectomy effects both on reference and working memory tasks.

Ovariectomy enhances acetylcholinesterase activity but does not alter ganglioside content in cerebral cortex of female adult rats.

In the present work we investigated the effect of ovariectomy on acetylcholinesterase (AChE) activity and ganglioside content in cerebral cortex of female rats. We also studied the activity of butyrylcholinesterase (BuChE) in serum of these animals. Adult Wistar rats were divided into three groups: (1) naive females (control), (2) sham-operated females and (3) castrated females (ovariectomy).

Ovariectomy increases Na+, K+-ATPase, acetylcholinesterase and catalase in rat hippocampus.

In the present work we investigated the effect of ovariectomy on Na+, K+-ATPase and acetylcholinesterase (AChE) activities in rat hippocampus. We also studied some parameters of oxidative stress, namely total radical-trapping antioxidant potential (TRAP), thiobarbituric acid-reactive substances (TBA-RS), as well as the antioxidant enzyme activities superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) activities. Our hypothesis is that ovariectomy might cause alterations in essential enzyme activities necessary to brain normal functioning and that these chances could be caused by oxidative stress.

Metabolism of amino acids by cultured rat Sertoli cells.

Sertoli cells support spermatogenesis both spatially and energetically; for this reason, these cells have important adaptations. The energetic metabolism of Sertoli cells was adapted to provide lactate and pyruvate to developing germ cells, because these substrates are essential for spermatocytes and spermatids. In this study, we investigated whether Sertoli cells use alanine, leucine, valine, and glycine as energetic substrates and whether the simultaneous addition of other nutrients, such as glucose and glutamine, might affect the metabolism of these amino acids.

In vivo and in vitro effects of homocysteine on Na+, K+-ATPase activity in parietal, prefrontal and cingulate cortex of young rats.

In the present study we determined the effect of chronic administration of homocysteine on Na+,K+-ATPase activity in synaptic membranes from parietal, prefrontal and cingulate cortex of young rats. We also studied the in vitro effect of homocysteine on this enzyme activity and on some oxidative stress parameters, namely thiobarbituric acid-reactive substances (TBA-RS) and total radical-trapping antioxidant potential (TRAP) in the same cerebral structures. For the in vivo studies, we induced elevated levels of homocysteine in blood (500 microM), comparable to those of human homocystinuria, and in brain (60 nmol/g wet tissue) of young rats by injecting subcutaneously homocysteine (0.