Telomeric DNA repeats are lost as normal somatic cells replicate. When telomeres reach a critically short length, a DNA damage signal is initiated, inducing cell senescence. Some studies have indicated that telomere length correlates with mortality, suggesting that telomere length contributes to human life span; however, other studies report no correlation, and thus the issue remains controversial. Domestic dogs show parallels in telomere biology to humans, with similar telomere length, telomere attrition, and absence of somatic cell telomerase activity.
Thiazolidine-4-carboxylic acid (TC) is a cyclic sulfur amino acid, a condensation product of cysteine and formaldehyde. The chemistry, biological effects and clinical use of TC are reviewed. Extensive animal experiments and studies on human subjects carried out in Europe indicate that a combination of TC and folic acid, 'Folcysteine', has revitalizing effects on age-related biochemical variables of blood and tissues. Further animal studies confirmed the anti-toxic effects of TC, particularly on the liver.
Proceedings of the National Academy of Sciences of the United States of America
A fundamental question in the basic biology of aging is whether there is a universal aging process. If indeed such a process exists, one would expect that it develops at a higher rate in short- versus long-lived species. We have quantitated pentosidine, a marker of glycoxidative stress in skin collagen from eight mammalian species as a function of age. A curvilinear increase was modeled for all species, and the rate of increase correlated inversely with maximum life-span.
The underlying mechanism of calorie restriction (CR) extension of mammalian life spans operates by altering the rate of decline in reserve capacity (with time) as well as the exposure to growth stimulus, two mechanisms that seem to be related to the central genetically determined mechanism that controls mammalian life span over a 50-fold range.
Components of the diet related to changes in eating habits that characterize the modern Western world are important factors in the increasingly high prevalence of chronic disease, including obesity, diabetes, hypertension and as a consequence, chronic kidney disease. The healthy diets recommended for the general population to promote longevity (such as the Mediterranean diet), are defined based on epidemiological and intervention studies and are usually characterized by a relatively higher amount of protein than the usual Western diet.
Long-term restriction of energy intake without malnutrition is a robust intervention that has been shown to prolong life and delay age-related morbidity. A 1H NMR-based metabonomic strategy was used to monitor urinary metabolic profiles throughout the lifetimes of control-fed and diet-restricted dogs. Urinary metabolic trajectories were constructed for each dog, and metabolic variation was found to be predominantly influenced by age. Urinary excretion of creatinine increased with age, reaching a maximum between ages 5 and 9 years and declining thereafter.
Companion animals represent an under-utilised resource. The present paper is designed to encourage collaborative studies. Dogs and cats are out-bred animals that are willing to consume a consistent diet for long periods, so are ideal candidates for prospective studies of naturally-occurring disease. In some studies the effect of diet on survival has been substantial.
OBJECTIVE: To determine the chronology of radiographic signs of canine hip dysplasia (CHD), specifically joint laxity and secondary osteoarthritis (OA). STUDY DESIGN: Longitudinal cohort study. ANIMALS: Paired littermates, 48 Labrador retrievers. METHODS: Conventional, ventrodorsal, hip-extended (HE) radiographs were evaluated yearly for CHD according to the subjective criteria of the Orthopedic Foundation for Animals (OFA). PennHIP screening was performed at 2 years of age to assess joint laxity by distraction index (DI).
Modeling aging and age-related pathologies presents a substantial analytical challenge given the complexity of gene-environment influences and interactions operating on an individual. A top-down systems approach is used to model the effects of lifelong caloric restriction, which is known to extend life span in several animal models.
The US has a pet population of approximately 70 million dogs and 74 million cats. Humans have developed a strong emotional bond with companion animals. As a consequence, pet owners seek ways to improve health, quality of life and longevity of their pets. Advances in canine and feline nutrition have contributed to improved longevity and well-being. Dietary fibers have gained renewed interest in the pet food industry, due to their important role in affecting laxation and stool quality.