The APS Journal Legacy Content is the corpus of 100 years of historical scientific research from the American Physiological Society research journals. This package goes back to the first issue of each of the APS journals including the American Journal of Physiology, first published in 1898. The full text scanned images of the printed pages are easily searchable. Downloads quickly in PDF format.

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A B S T R A C T Lipogenesis from glucose and lipolysisin human omental and subcutaneous fat cells were studied as functions of adipose cell size and number in adult females. Since subcutaneous fat cells were larger than those prepared from the greater omentum, a comparison could be made of the metabolism of different sizes of cells within individual subjects. Rates per cell of glyceride-glycerol and glyceride-fatty acid synthesis from glucose were similar in omental and subcutaneous fat cells incubated in the presence or absence of insulin. However, subcutaneous fat cells exhibited higher rates of basal lipolysis than omental fat cells and these differences were maintained when lipolysis was stimulated with theophylline. Different rates of lipolysis were not demonstrable after incubations with epinephrine, indicating that subcutaneous fat cells were less responsive to this hormone than smaller omental fat cells. Correlation and partial correlation analysis showed that differences in basal and theophylline-stimulated lipolysis between fat cells prepared from different subjects and between omental and subcutaneous fat cells could be accounted for A precise evaluation of the influence of adipose cell enlargement on its function requires that metabolic studies be performed on fat cells of different sizes prepared from the same fat depot. In the present investigation we have used an indirect approach to the problem, taking advantage of the fact that human subcutaneous fat cells are generally larger than those prepared from the greater omentum. It was thus possible to carry out paired comparisons in vitro of the metabolism of differently sized fat cells derived from a common in vivo internal environment. The data from different subjects were also examined to determine whether there was a correlation between the volume and metabolism of a fatThe Journal of Clinical Investigation Volume 49 1970 1213 cell independent of factors such as age and relative body weight. We reasoned that if both sets of analyses showed that adipose cell volume was the common factor in accounting for differences in cellular function within and between subjects, then this would be strong supportive evidence for an effect of cellular enlargement on metabolism. METHODSSource of adipose tissue. Samples of fat (8-12 g) were obtained from the subcutaneous tissues of the anterior abdominal wall and from the greater omentum of 31 subjects who were undergoing elective abdominal surgery. Operations were performed in the mornings after an overnight fast. Morphine and atropine or their derivatives were used for premedication. Anesthesia was induced with thiopentone sodium and maintained with nitrous oxide and halothane. Tissues were removed between 60 and 90 min after induction of anesthesia. On the basis of previous reports (9, 10) it has been assumed that variations in the duration and depth of anesthesia did not significantly affect the metabolism of subcutaneous and omental fat cells in vitro.Relevant clinical data as well and individual values for a...

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The presence of glycerokinase has been demonstrated in human omental and subcutaneous adipose tissue. The enzyme reaction showed a linear time course for 5 min at 30 C and pH optima at pH 7.6 and 9.0. Saturation of the enzyme was observed at 1.8 mM adenosine triphosphate (ATP) and the double reciprocal plot of activity vs. ATP concentration was nonlinear giving two apparent Km values of 0.094 and 0.518 mM. The apparent Km for glycerol, 0.112 mM, was obtained from a linear double reciprocal plot, and the enzyme was saturated at about 0.4 mM glycerol. The activity of glycerokinase in human adipose tissue excised under general anaesthesia was low and was unrelated to adipose cell size or the degree of obesity of the subject from whom the fat was obtained.