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Biomedical subjects

J M LOWENSTEIN

Publications and source records attributed to J M LOWENSTEIN.

At least 19 recordsLinked to original sources
PubMed1965

CITRATE AND THE CONVERSION OF CARBOHYDRATE INTO FAT. THE ACTIVITIES OF CITRATE-CLEAVAGE ENZYME AND ACETATE THIOKINASE IN LIVERS OF STARVED AND RE-FED RATS.

1. The activity of citrate-cleavage enzyme varies in accordance with the nutritional state of the animal. It is suppressed on starvation and restored on re-feeding after starvation. 2. The increase in enzyme activity that occurs on re-feeding starved animals depends on the diet. It is largest on diets high in carbohydrate and low in fat, and smallest on diets high in fat. Intermediate increases are obtained with balanced diets. 3. The ratio of activities of citrate-cleavage enzyme to acetate thiokinase varies from 2.5 for animals maintained on a balanced diet to 20 for animals re-fed with a diet high in carbohydrate. 4. The changes in activity of citrate-cleavage enzyme correlate with changes in the rate of fatty acid synthesis and provide evidence for the involvement of the citrate-cleavage reaction in fatty acid synthesis.

ATP Citrate (pro-S)-Lyase↗
PubMed1965

CITRATE AND THE CONVERSION OF CARBOHYDATE INTO FAT. ACTIVITIES OF CITRATE-CLEAVAGE ENZYME AND ACETATE THIOKINASE IN LIVERS OF NORMAL AND DIABETIC RATS.

1. The activity of citrate-cleavage enzyme declines in alloxan-diabetes. 2. The administration of insulin elevates the activity of the enzyme in livers of normal and diabetic animals. Diets high in glucose or fructose elevate the activity of citrate-cleavage enzyme in normal animals, whereas only the diet high in fructose does so in diabetic animals. These observations parallel the effects of insulin, glucose and fructose on fatty acid synthesis in normal and diabetic animals. The effect of fructose is brought into play more rapidly and is larger than the effect of glucose. 3. With one exception acetate thiokinase shows similar changes at a lower level of activity. 4. The results indicate that insulin acts by increasing glucose utilization, and not by exerting a direct effect on citrate-cleavage enzyme or acetate thiokinase.

ATP Citrate (pro-S)-Lyase↗
PubMed1964

CITRATE CLEAVAGE ENZYME IN LIVERS OF OBESE AND NONOBESE MICE.

The specific activity of the citrate cleavage enzyme is 3.3 times greater in livers of obese mice than in livers of their nonobese litter mates. The difference persists during starvation. The specific activity of the acetate activating enzyme is approximately the same in the livers of both types of animals. It is proposed that a high activity of citrate cleavage enzyme is one of the factors responsible for obesity.

ATP Citrate (pro-S)-Lyase↗