[Adipose tissue cellularity in the piglet as a function of the level of energy supply of the maternal diet and the number of young per litter]. / Cellularité des tissus adipeux chez le porcelet en fonction du niveaude l'apport énergétique du régime maternel et du nombre de jeunes par portée.

Adipose tissue cellularity has been evaluated in piglets at birth and at weaning at 35 days in relation with the energy supply of the maternal diet during gestation (group B: 3 000 KcalED/day: group N; 6 500 KcalED/day; group H: 10 000 Kcal/day) and with the number of piglets per litter during suckling. This approximation was obtained by simultaneously measuring piglet carcass triglyceride content and the mean diameter of the lipid inclusions of the fat cell population. At birth there were no significant differences between N and H piglets. However, B piglets weighed less and had lower lipid stores than the piglets of the other two groups. This lower adiposity was due to the smaller number of fat cells (about--25%). A weaning piglet weight and adiposity depended on both the energy supply of the maternal diet during gestation and the number of piglets per litter. These differences were due to the number of fat cells; this number was usually greater when the maternal diet during gestation had a higher energy level and the number of piglets per litter was smaller. Between birth and weaning the number of fat cells increased by a factor related with the number of piglets per litter; this factor was 1.9 or 2.5, depending on whether the sow suckled 4 or 8 piglets.

Cellularity of adipose tissue in fetal pig.

Adipose tissue cellularity was studied in the 85-day-old Large-White pig fetus. The aim of this work was to count the adipose cells of forming tissue in an animal species which could be a possible model for studying adipose tissue in humans. Using a morphometric method with electron microscopy, mean triglyceride volume per cell was determined independently of mean cell volume. This method is suitable for counting adipose cells in the early stage of differentiation whatever their size and lipid inclusion volume. Site-by-site dissection of adipose tissue was not feasible in the 85-day old fetus and adipose cell number was computed by dividing total carcass triglyceride volume by mean triglyceride volume per cell. The carcass triglyceride seemed to originate only from adipose cells. The mean total carcass triglyceride volume per fetus (1.84 g) was low but, owing to the low mean triglyceride volume per cell (180.28 microns3), the adipose cell number (11.15 X 10(9)) was relatively important, as it represented about 27% of the extramuscular adipose cell number in the Large-White adult pig (41 X 10(9)).

[Polyunsaturated fatty acids and aging. Lipofuscins : structure, origin and development]. / Acides gras polyinsaturés et vieillissement. Les lipofuscines : structure, origine, évolution.

In the last century, dense, pigmented bodies were observed on nerve cell sections, and the quantity of those pigments in the neurons was correlated to the age of the individual. Light microscopy has shown the presence of the pigments in the cells of most tissues and organs in both vertebrates and invertebrates, and they have also been seen in cultured cells. However, these commonly found cellular components have only have studied in detail since the last 25 years, using electron microscopic, histochemical and biochemical techniques to try to describe their nature, origin, development and possible physiological role. The comparable morphology, composition and physicochemical properties of these various pigments indicate that they are all produced by the same biochemical mechanism, including: 1) the peroxidation of the polyunsaturated fatty acids of cellular membranes by free radicals; 2) the reaction of lipid peroxidation end-products(s) with proteins, giving fluorescent polymerized compounds; 3) the combination of those polymerized elements and the peroxidized lipids. Different names have been used for these pigments, the most common of which in English are: "age pigment", "ceroid" and "lipofuscins". However, due to their common origin and their fluorescence, they are tended to be grouped under the term lipofuscins (in French: lipofuscines). Recent studies have confirmed that cellular lipofuscin concentration is definitely related to the physiological age of the individual. This concentration varies depending on the tissue and the organ; it is controlled by intrinsic regulatory factors, but also by environmental conditions, such as nutrition, physical activity, stress and hygienic conditions.

[Proliferation of adipose cells and their lipid accumulation in the rat at the perinatal stage; histoautoradiographic study]. / Prolifération des cellules adipeuses et leur remplissage par les lipides chez le Rat au stade périnatal, étude histoautoradiographique.

After thymidine-3H injection into pregnant Rat, histoautoradiographic studies showed that adipose cell proliferation in different subcutaneous and visceral sites, was very important in Rat foetuses about 24 h before birth and that lipid accumulation in the labelled cells was very fast during perinatal 48 h.

[Lipid overload induced in myocardial cells by vegetable oils. Observation using electron microscopy]. / Surcharges lipidiques induites dans les cellules du myocarde par des huiles d'origine végétale. Observation en microscopie électronique

Comparative studies were made to estimate the lipid overloading of myocardiac cells in rats fed by groups, for 3 and 6 days, one of the following dietary oils: peanut oil, maize oil, sunflower oi, soyabean oil, rapeseed-primor oil, rapeseed-canbra oil and rapeseed oil.