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Effect of 2-mercaptoethanol on some metabolic indices of ageing of CBA/Ca inbred mice

It has been shown in several studies that 2-mercaptoethanol (2-ME) improves the life span and aspects of life performance of laboratory animals. To obtain further details on the beneficial effects of 2-ME, a long-term study has been performed on male CBA/Ca inbred mice treated with this antioxidant. Four month-old mice were each given 4 micrograms of 2-ME in physiological saline via intraperitoneal (i.p.) injection 3 x per week. Measurements were made of the following: cold tolerance (heat performance), apparent total body protein turnover (T1/2), changes in the major lipid and fatty acid compositions of the liver, superoxide dismutase activity and formation of malondialdehyde and observations on a range of pathological changes. It was found that the basal rectal temperatures of the treated mice were higher and in the oldest group, heat performance capacity was better than those of the controls. After about 1 year of age the apparent biological half-life time of total body protein (T1/2) was observed to be shorter in the treated mice. Significant increases were observed to occur in the proportions of the polyunsaturated fatty acids in the lipids of the liver in the mice injected with 2-ME. Although no differences were observed in the superoxide dismutase activities, malondialdehyde concentrations in the livers of the experimental mice were significantly increased. Autopsy data showed that Dunn-sarcomas associated with amyloidoses occurred more frequently in the untreated mice.

Autoimmunity and normal immune functions in aged humans

The high frequency of ANA, A-LDL and RF in advanced age suggests that AABs are present in the majority of aged subjects. CIC incidence determined by three methods is far below AAB incidence; only the Clq solubility test suggests an increased CIC incidence in aged as compared to young subjects. Simultaneous occurrence of AABs of different specificities or CIC determined by two or three methods is rare and both AAB and CIC levels are usually low. AAB prevalence in CIC-positive individuals seems to depend on the specificity of the AAB. CIC positivity is associated with relatively low Clq concentrations; however, usually not with Clq concentrations below the normal range. Neither ANA nor CIC positivity seems to correlate with DNA synthetic response to PHA, but ANA positivity may be associated with low responses to allogeneic cells. ANA positivity and, to a lesser extent, CIC positivity seems to be connected with enhanced killer cell activity. The concept of some AABs and CIC as autoregulatory factors of the humoral immune system compensating for the thymus-dependent regulation in old age is stressed.

Lymphocyte subpopulation changes by aging

Peripheral blood lymphocyte suspensions of healthy young and aged subjects were tested for the percentage of (1) E-rosetting cells by three different modifications of the rosette technique; (2) alpha-naphthylacetate esterase positive cells of different staining patterns; (3) IgG-Fc receptor positive cells; (4) C3 receptor positive cells; (5) labile and stable bound surface immunoglobulin positive cells; and (6) cells bearing different classes of immunoglobulins on their surface or intracytoplasmically. Age dependent changes were registered both within the T-cell and the B-cell subpopulations, some of which may be due to in vivo activation of lymphocytes. Attention is called to some technical aspects of lymphocyte subpopulation determinations and to the significance of quantitative changes in the proportions of lymphocyte subpopulations in respect to the age dependent functional changes of lymphocytes.

Effect of aging on cold tolerance and thyroid activity in CBA/Ca inbred mice.

Relationships between cold tolerance, serum levels of thyroxine (T4), thyronine (T3), and thyrotropine (TSH), and thyroid morphometry have been investigated in male CBA/Ca inbred mice at various ages through their life span. From the data obtained it appeared that there was an age-related decrease in cold tolerance up to 18 months of age which was followed by an increase, the age effect being most apparent in relation to cold resistance and cold tolerance during the recovery period following cold exposure. The age-related changes in cold tolerance appeared to be associated with changes in the serum concentrations of T3, T4, and TSH. In contrast to the T3 serum levels which showed a decrease at 36 months, the thyroxine contents showed a perceptible decrease from the age of 12-18 months onwards. A similar pattern was observed for the TSH levels, with a peak at 21 months, followed by a decline at 30 months. A relationship with age between serum T4 level and thyroid weight was indicated together with structural changes in the thyroid gland, particularly during senescence, for example the size and number of thyroid epithelial cells had become enlarged by 30 months of age.

Lipofuscin in lymphocytes and plasma cells in aging

The age-related changes in spleen and lymph node lymphocytes and plasma cells of Wistar rats and in the peripheral lymphocytes of healthy human individuals were examined. Similar changes were described in human and rat lymphocytes and plasma cells consisting of mitochondrial lesions. The cristae of the mitochondria disappeared and were replaced by myelin-like structure, lamellar structure, electron-dense and electron-translucent material. It is supposed that this material corresponds to lipofuscin.

Long-term observations on the effect of polyadenylic acid in mice of different ages

In order to better life performance, polyadenylic acid (poly (A) ) was given intraperitoneally to CBA/Ca mice for almost a two-year period. This substance, as one of the components of double-stranded polynucleotides (like poly A:U), is known to improve some immune responses of the aging organism. Five approaches (changes in body-weight, adaptation to cold stress, biological half-life of body proteins, mortality and pathology) were applied to test the effects of this substance on life performance. It was found that the beneficial effects of double-stranded polynucleotides cannot be mimicked by polyadenylic acid only, despite its anti-senescence effect, namely, it accelerates the apparent protein turnover, cf., biological half-life. Polyadenylic acid shortens life-expectancy (because of the higher mortality rate of mice). Possible mechanisms of these actions are discussed.

EDUCATION TO PROMOTE HEALTHY AGING IN HUNGARY

Demographic changes have altered medical practice, shifting the focus to the health care problems of the aged. These changes challenge health policy and services and require adjustments in the content of both undergraduate and postgraduate health professional curricula. The undergraduate and postgraduate medical teaching at the Gerontology Center of the Semmelweis University of Medicine in Budapest is described. In the future, it will be important to include medical gerontology in the curricula of all four medical schools in Hungary.