The Effect of Caloric Restriction on the Aortic Tissue of Aging Rats

Abstract

Tribute to Ines by Ivonne RonchettiI first met Prof. Ines Mandl in Orvieto in 1979 at the meeting on elastin organised by Prof. G. Quintarelli. I was just at the beginning of my participation in international meetings in the field. I was impressed by the energy, character and also by the great humanity of Prof. Mandl. With great pleasure I discovered that she and her husband knew Italy so well; its art, architecture and language. It was a real pleasure to walk and talk with them in the evening through Orvieto. I must also admit that I felt a little jealous of Prof. Ines Mandl, for her professional cultural accomplishments and also for her being accompanied by her husband. My husband came to a scientific meeting once, in 1968; he promised himself it was the last and he kept his promise. After 20 years, I feel honored to participate in this celebration that is also an occasion to bring back to memory friends and colleagues met along life's journey. There is also another reason that makes me happy to participate in this celebration of Prof. Mandl: she is a woman.Connective tissue shows peculiar and complex age-related modifications, which can be, at least in part, responsible for altered functions and increased susceptibility to diseases. Food restriction has long been known to prolong life in rodents, having anti aging effects on a variety of physiologic and pathologic processes. Therefore, the aorta has been investigated in rats fed normal or hypocaloric diet, from weaning to senescence. Compared with controls, caloric-restricted animals showed less pronounced age-dependent alterations such as elastic fiber degradation, collagen accumulation and cellular modifications. Immunocytochemical analyses revealed that elastic fibers were positively labelled for biglycan, decorin, ApoB100 (LDL), ApoA1 (HDL) and elastase and that the intensity of the reactions was time- and diet-dependent. With age, the major changes affecting aortic elastic fibers were increased positivity for decorin, LDL and elastase. Compared with age-matched normal fed rats, caloric restricted animals revealed lower content of LDL, decorin and elastase and higher positivity for HDL. These data suggest that a caloric restricted diet might influence the aging process of the arterial wall in rats, delaying the appearance of age-related degenerative features, such as structural alterations of cells and matrix and modified interactions of elastin with cells and with other extracellular matrix molecules.