S A Erat

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Research from our laboratory has indicated that the loss of sensitivity that occurs in several receptor systems as a function of age may be an index of an increasing inability to respond to oxidative stress (OS). This loss occurs partially as a result of altered signal transduction (ST). Assessments have involved determining the nature of age-related(More)
Although there are numerous findings which suggest that the pathogenesis of age-related neurodegenerative disorders (e.g., AD and PD) may involve oxidative stress (OS), relationships between functional age-related neuronal deficits, especially those with behavioral correlates, and OS have been difficult to establish. We have attempted to establish such(More)
Administration of buthionine sulfoximine (BSO) selectively inhibits glutathione (GSH) biosynthesis and induces a GSH deficiency. Decreased GSH levels in the brain may result in less oxidative stress (OS) protection, because GSH contributes substantially to intracellular antioxidant defense. Under these conditions, administration of the pro-oxidant, dopamine(More)
The effects of exposure to ionizing radiation on behavior may result from effects on peripheral or on central systems. For behavioral endpoints that are mediated by peripheral systems (e.g., radiation-induced conditioned taste aversion or vomiting), the behavioral effects of exposure to heavy particles (56Fe, 600 MeV/n) are qualitatively similar to the(More)
Previous research has suggested that age-related decline in physiological functions may be the result of substantial alterations in membrane molecular structure. The purpose of the present experiments was to elucidate the role of cholesterol domains in the age-related decline in receptor-G-protein interactions in striatal synaptosomes. We observed a(More)
The striatum contains a high concentration of oxidizable dopamine (DA), and the aged organism shows a decreased ability to respond to oxidative stress (OS), making this area extremely vulnerable to free radical insult. To determine the receptor specificity of this putative increase in OS sensitivity, striatal slices from 6- and 24-month-old animals were(More)
Previous research has indicated that many age-related functional alterations may be the result of a decreased ability of the organism to respond to oxidative stress (OS). However, this hypothesis is based on indirect indices of function (e.g., increased vulnerability of hepatocytes from senescent animals to H2O2-induced DNA damage, increases in lipofuscin(More)
There is evidence that dietary lipids and age both influence neuronal membrane composition and receptor G protein-linked signal transduction, but very little information is available on the interaction between these two factors. To investigate this, we obtained striata from 2, 12, and 22-month-old male F344 rats who were fed either a high-cholesterol,(More)
Previous research from several laboratories has indicated that cholesterol (CHO) accumulates in neuronal membranes and alters their structural and signal transduction (ST) properties during aging. The possible reasons for these increases in membrane CHO have not been specified. However, present findings suggest that such accumulation may actually serve to(More)
The effects of a reduced calorie-high fiber diet (RCHF) were examined on three cholinergic signal transduction (ST) parameters: (a) oxotremorine enhancement of K(+)-evoked dopamine release and (b) carbachol-stimulated low KM GTPase activity [an indicator of muscarinic receptor (mAChR)-G protein coupling/uncoupling], and (c) [3H]Quinuclidinyl benzilate (QNB)(More)