Lois M. Zucker

Hereditary Obesity in the Rat Associated with High Serum Fat and Cholesterol.

Summary A rat mutation leading to obesity noticeable by 5 weeks of age and produced on a low fat stock diet is described. It is associated with approximately normal blood sugar levels, but with a spectacular hyper-lipemia, involving a 10-fold rise in total fatty acids, 4-fold rise in cholesterol and lipid phosphorus, and a milky appearance of the blood serum.

Efficiency of Energy Utilization by the Zucker Hereditarily Obese Rat “Fatty”

Summary The hereditarily obese rat “fatty”, with food intake restricted to approximately normal, laid down excessive fat at the rate of 0.56 g rat per day for up to 74 days on experiment, producing an energy denser, but lighter weight, carcass than the normal control. The “fatty” retained over 20% of the energy supplied, in its carcass, the control less than 10%. Technical assistance from the following persons is gratefully acknowledged: Mrs. Olive R. Hekkala, Mrs. Ann Thompson, Mrs. Martha Thome, and Mrs. Meimi Grekula.

Animal protein factor and vitamin B12 in the nutrition of animals.

Publisher Summary This chapter focuses on “animal protein factor” and the role of vitamin B 12 in the nutrition of animals. Vitamin B 12 is a chemically and physically characterized cobalt coordination compound, which has been isolated from liver and from the culture medium of certain molds. It is the antipernicious anemia substance of liver and also plays the role of a nutritional essential for certain microorganisms, for birds and for mammals. Three different forms of such a Co coordination compound (B 12 , B 12a , B 12b ) have been found that have B 12 activity. There are many present indications that crystalline B 12 possesses all the activity that is connoted by animal protein factor as represented by liver, liver extract, fish meal, fish solubles, etc. This is based largely on curative experiments. There are also indications from other lines of experimentation that whole liver and a Streptomyces aureofaciens preparation contain materials that are not B 12 but have activity that may come under a heading of “animal protein factor” activity. With regard to the relation of B 12 to metabolic processes, it is established that the requirement or effectiveness of B 12 varies with the protein intake and similar relations to fat are indicated.

Duodenal Ulcers Produced on a Diet Deficient in Pantothenic Acid.

It is well known that various nutritional essentials are concerned with the maintenance of normal epithelial tissue. As part of a program concerning nutritional deficiencies and gastrointestinal epithelium, we have reported the finding of marked antral gastritis on calcium deficient diets. 1 Similar, less marked and less constant lesions were also reported on thiamine deficiency. Under various conditions of inanition the fundic mucosa will show rather typical areas of hemorrhage. 2 Previously, many papers have appeared on the involvement of nutritional deficiencies in the production of hyperplasia of the forestomach epithelium of rats. 3 In none of these cases, even when modifications were introduced to accentuate the process, have penetrating lesions been observed which could in the narrower sense of the word be designated as ulcers or which resembled typical ulcers as they occur spontaneously in man. Further observations have shown that on a diet deficient in pantothenic acid penetrating ulcers are produced in rats. The diet contained all the known nutritional factors necessary for growth except pantothenic acid, and had the following composition per 100 g of diet: vitamin “free” casein (Labeo) 18.0; cerelose 71.9; salt mixture 6.1 (Ca 1.0, P 0.55); cottonseed oil 2.0; celluflour 2.0. Incorporated in the oil were 10 mg alpha tocopherol and 1500 international units of vitamin A as carotene. The celluflour carried: thiamine HO and pyridoxine HO 1 mg each; riboflavin 2 mg; niacin 4 mg and 2-methyl-naphthoquinone 0.5 mg. Out of a larger group covering various age ranges, 45 animals have been autopsied: 23 older rats with an initial age averaging 394 (271-620) days and 22 younger rats starting at 42 to 105 days. The average experimental time for the older animals was 100 (67-140) days and for the younger one 125 (87-185) days.

Does animal protein factor occur in green plants

Summary A postweaning growth inhibition in the offspring of rats on a well fortified all-plant ration has been described. While this is corrected by a factor in liver, neither alfalfa leaf meal, dried grass nor young fresh grass have such an effect.

Significance of the Protein Level in Synthetic Diets

Summary It has been reported by McIntire et at. that a diet containing 18% purified casein and 6 pure B factors does not support optimal growth in male rats, and that the missing factor is present in liver extract. Evidence is presented to show that the factor, whatever it is, may not easily be found in the usual concentrated sources of B complex, but rather that it is associated, whether as an impurity or an essential amino acid, with protein of good quality.

Acetylating activity in the rat in relation to other signs of pantothenic acid deficiency

Abstract Acetylation of sulfanilamide in vivo has been followed with hourly urine collections in normals of varying body weight, and in adult rats during the development of pantothenate deficiency. As the deficiency progresses the general level of the acetylation time curve drops, and the shape of the curve changes systematically. Rats placed at weaning on a partial pantothenate deficiency show acetylation curves very similar to those of adults on a total deficiency after the same experimental time, 15 weeks. These two age groups are by this measure equally deficient at this time. The two age groups differ at this time in two other manifestations of the deficiency: susceptibility to infection by a corynebacterium and development of duodenal mucosal lesions and ulcers, the young rats developing the infection and the adults the duodenal changes.

Kidney hypertrophy in B complex deficiency.

Summary B-complex deficiency in 20 young rats resulted in kidneys which were 50% overweight. Nine rats which served as inanition controls showed no enlargement. Among the 3 types of food controls those which lost weight had kidney weights below the norm; where body weight was kept constant the kidney weights coincided with the norm based on stock diet animals.