Evidence for increased degeneration of mitochondria in old rats. A brief note

An isotonic density gradient technique for separating mitochondria into two major components was applied to mitochondria isolated from young and old rats. Respiratory measuremtns indicate that the depression of state 3 respiration rates observed in the mitochondria from old rats when glutamate--malate is used as a substrate is due primarily to the faster sedimenting mitochondrial component.

Altered enzymes in the free-living nematode, Turbatrix aceti, aged in the absence of fluorodeoxyuridine

Aging of the free-living nematode, Turbatrix aceti, has been accomplished by a procedure based upon screening of the cultures every 3--4 days to remove newborn organisms. In this system, the enzymes, isocitrate lyase, phosphoglycerate kinase and enolase all show reduced specific activities with age in crude homogenates. More critically, pure enolase shows a reduced specific activity when isolated from old compared with young organisms (958 units/mg vs. 1340 units/mg, respectively). Immunotitration experiments confirm these results. Enolase from old T. aceti requires more antiserum per unit of enzyme activity than does enolase from young organisms. This relationship holds true for both crude homogenates and pure enzyme. The above results closely parallel previous results obtained using fluorodeoxyuridine to prevent reproduction of T. aceti during aging of the organisms. Therefore, use of fluorodeoxyuridine in the aging of nematodes is perfectly safe, at least with respect to results obtained with altered enzymes.

Development of the aging cell surface: concanavalin A-mediated intercellular binding and the distribution of binding sites with progressive subcultivation of human embryo fibroblasts

External surfaces of early and late passage human embryo fibroblasts were reacted with concanavalin A to determine whether quantitative and qualitative variations in receptor sites develop with increased serial subcultivation. Comparative analyses of direct con A binding to cell surfaces; lectin-mediated cell-to-cell binding and agglutination; and ultrastructural distribution of con A receptor sites were made on the surfaces of both cell groups. Subtle variations were observed in the patterns of intercellular binding between early and late passage cells as assayed by both agglutination and the binding of cells in suspension to substrate-attached monolayers. However, no major differences in the total number of binding sites per cell were expressed on the external surfaces of either group. Hemocyanin-labeled binding sites tended to be more clustered on membranes of late passage cells in contrast to more homogeneous patterns of distribution in early passage specimens. These observations suggest that variations in binding patterns are not the result of changes in numbers of binding sites but may be the result of alterations in the concerted actions of numerous factors which include cell surface topography (e.g. villous projections) and the relative distribution of lectin binding sites on the cell periphery.

Alteration of the activity and molecular from of thymidine kinase during development and aging in the mouse cerebellum

Protein, DNA and thymidine kinase levels were assayed during development and aging in the mouse cerebellum. A roughly parallel increase in protein and DNA content occurred from birth, reaching a plateau at 18 days; these adult levels increased by 30% in the 23 month-old cerebellum. Thymidine kinase activity reached a maximum at 6 postnatal days, then decreased steadily to reach, at 18 days, the low level that was maintained in the adult. The thymidine kinase synthesized in the aged cerebellum differed from that in the neonate by having (i) an increased specific activity, (ii) a faster migrating species upon electrophoresis, (iii) an inhibition by dCTP, and (iv) a lower affinity for the substrate thymidine (higher Km). Mathematical calculations indicated the appearance of a larger number of smaller sized cells in the aged cerebellum, when compared with the young adult. Histological analysis established that the newly synthesized cells were localized in the molecular layer of the old cerebellum. It appears that senescence in the mouse cerebellum may be associated with an increased synthesis of glial cells.

Influence of the geroprotector 2-ethyl-6-methyl-3-hydroxypyridine hydrochloride on the lifetime of Drosophila melanogaster

A slowdown of the aging process was established in Drosophila melanogaster than received the geroprotector 2-ethyl-6-methyl-3-hydroxypyridine hydrochloride. The action of the preparation in a dose of 0.01% at the larval stage of development leads to an 18--20% increase in the average lifetime of females and males and lengthens the maximum lifespan of males. The older the individuals by the beginning of the experiment, the weaker the influence of the geroprotector: The average lifetime of females taken in the experiment at one day old is increased 12%; the influence at an age greater than 20 days is ineffective.

The linear regression of body weight and age in intact, ovariecotomised, and estrogen treated rats: some applications and implications

Many variables, including rat body weight (BWt), are sequentially measured in individuals yet the information obtained is often poorly utilised. Many advantages result if a linear relationship is established, on the original or transformed scales, between the variable and time. For individual rats log BWt, which is normally distributed, is linearly related to the reciprocal of age. Slopes (rates of BWt gain) and constants (ultimate BWts) then serve as data. Linearity extended from 4 weeks onwards in ovariectomised (OvX) and intact rats, implying that puberty does not affect BWt and that BWt increases before puberty following pre-pubertal OvX; the ovary inhibiting growth before puberty. For individual rats weaning BWt was correlated with rate of BWt gain but not with ultimate BWt, indicating postweaning compensatory growth which continues to maturity. Pre-treatment and post-treatment measurements were made on individuals, allowing within-animal comparisons and regression. Thus the BWt response to OvX or estrogen treatment depended on the pre-treatment rate of BWt gain and ultimate BWt, implying that the BWt response entails a form of compensatory growth. OvX at three ages (day 2, week 4, and week 7) produced different rates of BWt gain but similar ultimate BWts. These results support the hypothesis that ultimate BWt is predetermined, but can be modified by treatment.

Is there a biological basis for geriatric pharmacotherapy?

The problem of developing a geriatric pharmacotherapy is briefly discussed. It is stressed that combined scientific knowledge from biological, clinical and pharmacological research should be used as basis. However, in applied (clinical and pharmacological) gerontology, direct relations to basic experimental gerontology are often avoided, because of its seemingly theoretical character. With some examples, it is pointed out that during the recent past, biological-aging research has gained new knowledge, particularly on skeletal muscle and CNS aging, that can be used in the concept of a specific geriatric pharmacotherapy.

Dihydroergotoxine(Hydergine) and ethanol-induced aging of C57BL/6J male mice

The residual effects of dihydroergotoxine (Hydergine), ethanol, and Hydergine-plus-ethanol were investigated in old male mice of the C57BL/6J strain. Prolonged 10% v/v ethanol, concomitant with adequate nutrition, produced a significant decrease in life-span, decreased spontaneous locomotor activity and reduced lipofuscin accumulation in neurons of the reticularis gigantocellularis. These effects were not apparent in mice treated with Hydergine or alcohol combined with Hydergine.

Hypothesis testing in younger and older alcoholics

Older alcoholics used less systematic approaches to problem solving and were not able to solve as many problems as younger alcoholics or controls.