Age dependence of signal transduction and cell signaling as a major factor of intervention into the aging process.

Nowadays, it has become necessary to investigate the mechanisms underlying aging changes and their modulation. Of particular interest are the cellular and molecular level cell-cell and cell-matrix interactions. Thus, we partly determined in rats aged 9 and 31 months (a) the concentrations and the activities of signal molecules, such as G-proteins, cyclic adenosine monophosphate (cAMP) and kinases (cellular) and collagens, proteoglycans (PG) and fibronectin (extracellular) in vivo in the skin of the back, as well as in isolated fibroblasts and keratinocytes; (b) the cell proliferation and (c) we tried to retard the aging process in the skin by topical application (or by addition to cell cultures) of fetal mesenchymal cells, PGs, and soya matrix and we compared the above mentioned parameters with those obtained by stimulation of skin cells with growth factors.

Age-dependent changes in cardiovascular and metabolic responses to exercise in beagle dogs.

There is little data available on age-dependent changes in cardiovascular and metabolic functional capacity in older dogs and their geriatric importance, although the frequency of cardiovascular diseases increases with age in the dog, too. Thus we investigated major cardiovascular and metabolic parameters during and after physical exercise by treadmill-running in 5-10 year-old Beagles. We analysed electrocardiograms, body temperature, haematology, blood chemistry and blood gases.

[Is selection for extended life expectancy possible by regularity in aging?].

To answer this question it is important to explain the mode of development of the different maximum life span potentials (MLP) during evolution. We know by empiric-historical investigations, that at least later in evolution appearing species of mammals possess a higher MLP. What does then mean a "regular process"? The aging process is a regular one, being a physiologic event, in the character of that what all we can determine at it, as far as it allows explanation and prediction.

The effect of aging on laboratory values in dogs.

The main objective of this study was to examine age-associated changes in laboratory values in dogs in order to establish standard values for dogs of a certain age. These standard values could serve to judge the health status of individual dogs and possibly estimate their remaining life expectancy. Thus, haematological and immunological parameters, plasma constituents, kidney characteristics and the capacity of homeostasis were determined in German shephard dogs (0.

Assessment of modifications of the rate of aging in the rat.

Multivariate models of BA are, at present, the only way of measuring the main subject of gerontological research, namely, aging of the organism as a whole. Aging is obviously not a completely random process without any regularity, but shows a pattern which is determined by the organism's principles of order and its answer to the stochastic events of primary aging. Based on this theoretical concept, which is supported by results of factor analysis, multicellular aging may be described by a single complex variable, BA.