Changes in water solubility of proteins in aging rat brain

Effect of hormone replacement therapy in normalizing age related neuronal markers in different age groups of naturally menopausal rats

Aging of the normal brain is accompanied by changes in its structure, function, and metabolism. There are significant gender differences in aging brain. Most of these changes increase during menopausal condition in females when the level of estradiol and progesterone are decreased. The objective of this study was to determine the effect of estradiol and progesterone (separate as well as combined) hormones in neuronal tissues from naturally menopausal rats of different age groups. Results show decreased activity of Acetylcholine esterase (AChE) whereas the level of lipid peroxidation increased with age, and after the hormone treatments both AChE activity and level of lipid peroxidation returned to control values. The deposition of lipofuscin, a pigment that accumulated intraneuronally in brain and other tissues and is considered a marker of aging, was increased with aging and the hormone treatment decreased this deposition. The present study clearly shows reduction in risk factors associated with aging in the murine model system by hormone treatments, namely estrogen and progesterone by increasing the activity of acetylcholine esterase and decreasing the levels of lipid peroxidation and lipofuscin deposition in different parts of aging brain. This study suggests that hormone replacement therapy may either reduce or delay the onset of age related diseases like Alzheimer's, Parkinson's and other neurological disorders.

Effect of postmortem storage on the [3H]hemicholinium-3 binding site in the rat brain. Preliminary study for investigations of human patients with Alzheimer's disease

The effect of postmortem storage at room temperature (24-26 degrees C, 0-4 h) and cold-room temperature (4 degrees C, (0-24 h) on the [(3)H]hemicholinium-3 binding sites in the brain hippocampus, cortex and cerebellum of 3-month-old Wistar rats was studied. A slow decrease in the density of the binding sites was observed at both temperatures, which was best fit by a linear model common for all three brain regions. No systematic alterations of the affinity of the binding sites for hemicholinium-3 were found. The values obtained from experiments with animals were compared with the values measured in the frontal cortex of old men. Approaches to the evaluation of data obtained from postmortem samples of human brain tissue of patients with Alzheimer's disease are proposed.

An antistress and antiaging neurometabolic therapy. Accelerated lipofuscinolysis and stimulated anabolic regeneration by the antagonic-stress synergistic formula

In both stress and aging, an etiopathogenic analysis demonstrates in the brain some common mechanisms and reciprocal accelerating relationships: hypoanabolism (decrease of RNA and protein synthesis), coupled with hypercatabolism (increase of oxidative stress-lipid peroxidation, with waste product accumulation: lipofuscinage pigment and water-insoluble proteins). For therapeutical intervention in these antihomeostatic processes, we successively (1972-1992) developed a neurometabolic antioxidative therapy--finally represented by a specific antistress and antiaging synergistic formula, Antagonic-Stress. Its homeostatic actions have been demonstrated in the stressed aging brains by reestablishing the anabolism/catabolism balance: anabolic regeneration by increasing total RNA, total proteins and water-soluble proteins, coupled with catabolic regulation by accelerated lipofuscinolysis and age pigment elimination (neuronal-->glial-->capillary route) and decreasing of water-insoluble proteins. Specific, synergistic, and superior actions of Antagonic-Stress multiple formula vs. antistress and antiaging monotherapy have been demonstrated by preclinical and clinical studies, confirming our results.

Early postnatal diazepam treatment of rats and neuroimmunocompetence in adulthood and senescence

Functional teratogenic risk of perinatal diazepam (D) treatment was studied in animal model experiments using early postnatal D administration in rats (single dose of 10 mg/kg sc in 7-day-old pups) and long-term follow-up till the age of 18 months with monitoring of behavior, reproductive functions, brain biochemical variables, and immune system reactivity. Behavioral tests carried out at the age of 6, 12, and 18 months indicated higher emotionality and deviations of novelty reaction in D rats in comparison with controls, and these differences decreased with aging. However, no deficits were found in memory testing. D rats revealed some transitional alterations of monoamine neurotransmission in the hypothalamus (5-HT) and striatum (DA) and minor defects in reproductive functions (irregular estrous cycles in females). Significant depression of immune response in D rats persisting for the whole life may be considered as a serious risk of neonatal D treatment.

High-affinity choline uptake and muscarinic receptors in rat brain during aging

The aim of this study was to determine the effect of aging on the high-affinity choline uptake (HACU) and the muscarinic acetylcholine receptors (mAChR) in the brain of Wistar male rats and to define more precisely the steps of the brain cholinergic degeneration in the course of the whole animal life. In 24-month-old rats, a substantial decrease in HACU values in the hippocampus (to 65-75%) and in the density of mAChR in the cortex (to 76%) was found in comparison with 3-month-old controls. The interaction of muscarinic receptor antagonist pirenzepine with [(3)H]QNB indicated a decrease in low-affinity sites (M(2)) in 24-month-old rats. The first slight changes due to aging manifested themselves by the reduction in HACU values very early (between 6 and 12 months), the decrease of the muscarinic receptor density was observed in a later stage (19-month-old animals). Regression analysis indicated considerable dependence of the HACU values on age (the correlation coefficient r = -0.689, the slope b = -0.279 pmol/4 min per mg(prot) per month, P < 0.001) while the density of muscarinic receptors does not correlate with age so markedly (r = -0.415, b = -6.316 fmol/mg(prot) per month, P = 0.018).