Growth and longevity of Wistar rats receiving a diet whose protein content is rapidly lowered in relation to aging]

Growth and longevity of the Rats were the same when: (i) the diet was rich in casein (21%), from weaning to death: (ii) the casein content of this diet (without B12) was progressively lowered from weaning to 200 days of age, and thereafter was 7%. When the casein level had been too rapidly lowered, inducing retardation of growth after 75 days, maximal growth was lowered and life span was increased.     

Growth and the average duration of larval life in the southern hemisphere lamprey,Geotria australis Gray

Summary The average duration of larval life in the anadromous lamprey,Geotria australis (the sole representative of the Geotriidae) is estimated as 41/4 years. Compared with other lampreys, the ammocoetes ofG. australis have a slow growth rate, increase in length during the year preceding metamorphosis and typically enter metamorphosis at a small mean length (<100 mm) and weight (<1.2 g).     

Effect of alpha-tocopherol (vitamin E) on the utilization of vitamin A and induction of cytochrome P 450 in rats receiving DDT]

During detoxication processes of DDT, there is, in the Rat, interference between vitamins A and E (D.1.alpha-tocopherol acetate). Vitamin E spares retinal and has a slighter but significant influence on P 450 cytochrome induction. These results are discussed.     

Experimental liver fibrosis induced in rats receiving high doses of alcohol and alternating between regular and vitamin-depleted diets

Liver fibrosis was induced in rats by simulating human alcoholic eating and drinking patterns. Alcohol addiction was established by gradually increasing the ethanol concentration in the drinking water; salts were added at the terminal stage. The hepatocytes of rats receiving alcohol concentrations exceeding 50% (v/v) (similar to vodka) exhibited alcoholic hyaline (Mallory bodies). Alcoholic liver fibrosis was induced by alternating between regular and autoclaved (vitamin-depleted) diets, simulating the irregular eating habits of human alcoholics. In the livers of rats receiving 70% (v/v) ethanol (comparable to absinthe) with 25% saline and fed the alternating diets, pericellular fibrosis was induced. No significant difference in calorie intake between control and alcohol rats was detected except when rats underwent drinking bouts (heavy drinking phase). This indicates that neither a high-fat diet nor a choline-depleted diet is necessary to induce the alcoholic fibrosis seen in human alcoholics.     

Night pineal N-acetyltransferase activity in rats exposed to white or red light pulses of various intensity and duration

Summary Night N-acetyltransferase activity is suppressed by red and white light; the red light intensity, however, must be 10 times higher. Short light pulses also suppress night N-acetyltransferase; the higher the light intensity, the shorter the pulse is effective.The authors are grateful to Mrs Marie Svobodová for her skillful technical assistance.     

Vitamin A consumption in pregnant and non pregnant rats, and in castrated rats receiving or not receiving estradiol or pregnenolone; relation to tocopherol and cytochrome P-450]

Consumption of vitamin A and cytochrome P 450 by pregnant Rat is more important than in non pregnant and ovariectomised Rat. Estradiol implant in ovariectomised female has some, but slighter, influence only on retinol. These physiological situations have no action on the hepatic levels of tocopherols (total and alpha). These results are discussed.     

Spontaneous activity of rats on diets varied in protein,carbohydrate and fat content

Résumé Nous avons mesuré l'activité spontanée de rats mâles et femelles recevant des rations contenant 10%, 25% et 60% de protéine et 29% de graisses non-saturées ou 31% de graisses saturées. Les rats ont été maintenus isolés dans des cages à stabilimètre 6 jours de suite. On a comparé les données obtenues pendant les 3 derniers jours. On n'a pas trouvé de différences significatives dans l'effet des différents régimes, ni pour les mâles ni pour les femelles.

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This work was supported in part by a grant from the National Institute of Neurological Diseases and Blindness, No. NB 01941, of the National Institutes of Health, U.S. Public Health Service, Bethesda, Maryland, and the Fund for Research and Teaching of the Department of Nutrition, Harvard School of Public Health, Boston, Massachusetts.     

Adaptation of lipase and phospholipase A activities in pancreas and pancreatic juice in rats with diets rich in triglycerides and phospholipids]

Lipid rich diets containing about 20% of triglycerides or phospholipids given to Rats during 2 months were observed to increase lipase and phospholipase A2 activities in pancrease and pancreatic juice. The phospholipase and lipase activities are higher, respectively, on the phospholipid and triglyceride diet. Lower effects are observed after a 7-day administration of diet containing 40% of total lipid.     

Consumption of vitamin A in intact and castrated rats. Relation to tocopherol and cytochrome P 450]

There are significant differences between castrated and non castrated male Rats in regard to vitamine A hepatic storage and plasma level. Cytochrom P 450 levels are the same in both groups. Those results are discussed.     

Synergism between long-acting bromocryptine microcapsules and cyclosporine A in the prevention of various autoimmune diseases in rats

Pre-treatment of male Sprague-Dawley rats with long-acting bromocryptine microcapsules (CBLA) significantly inhibited the arthritic response to Freund's complete adjuvant and reduced weight loss, thymolysis, splenomegaly and leukocytosis. In the prevention of adjuvant arthritis (AA), the combination of CBLA plus sub-optimal doses of cyclosporine A (CsA) was more efficient than either of the drugs alone. Sub-optimal doses of CsA were 0.1 and 1.0 mg/kg/day s.c. for 5 days. Furthermore, CBLA alone did not decrease the incidence of experimental allergic uveitis (EAU) in the male Lewis rats. Low-dose CsA reduced the incidence of uveitis by 50%, and with the addition of CBLA, 100% of rats were protected. Low-dose CsA was 2 mg/kg/day i.m. for 14 days. Long-term treatment of male Sprague-Dawley rats with CBLA alone reduced the incidence and severity of spontaneous autoimmune periateritis nodosa (PN) in a dose-dependent manner; CsA was less potent than CBLA, and only additive effects were obtained. Finally, for the prevention of spontaneous autoimmune insulin-dependent diabetes (DM), the administration of CBLA did not improve the effect of a low-dose CsA in male BB rats. Nevertheless, a delay in onset of DM could be achieved. A sequential therapy using CsA plus CBLA clearly showed beneficial effects. The dose of CsA was 10 mg/kg p.o. 6 days/week for 21 weeks. Compared with Sprague-Dawley or Lewis male rats, BB male rats showed only weak prolactin suppression after the same doses of CBLA. It is suggested that the use of CBLA may be particularly beneficial in autoimmune disorders. The effectiveness of the combination therapy CBLA plus CsA, however, was dependent on the model considered. Various factors could play a role: (1) the different ways of administering CsA (s.c. in AA, i.m. in EAU and PN, oral in DM); (2) strain-dependency in the capacity of CBLA to suppress Prl secretion; and(3) at least in the BB rats, the transient increase of CsA bioavailibility which was possibly induced by CBLA.