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...

The present study aimed to examine a wide profile of acute biochemical and neuromuscular responses to strength (STR) and hypertrophy (HYP) resistance exercise (RE). Seven trained males completed a STR workout (4 x 6 repetitions, 85% one repetition maximum [1RM], 5 min rest periods), a HYP workout (4 x 10 repetitions, 70% 1RM, 90s rest periods) and a control condition (CON) in a randomised cross-over design. Peak force (PF), rate of force development (RFD) and muscle activity were quantified pre-and post-exercise during an isometric squat protocol. Blood samples were taken 20, 10 and 0 minutes pre-and 0, 10 and 60 minutes post-exercise to measure the concentration of blood lactate (BL), pH and a number of electrolytes that were corrected for plasma volume changes.No differences were observed between the workouts for changes in PF, RFD or muscle activity.Repeated contrasts revealed a greater (p ≤0.05) increase in BL concentration and reduction in pH following the HYP protocol than the STR or CON conditions. There were similar but significant (p ≤0.05) changes in the concentration of a number of electrolytes following both workouts and a handful of these changes displayed significant correlations with the PF reductions observed following the HYP condition. Although the STR and HYP workouts were significantly different in terms of intensity, volume and rest, these differences were only observable in the acid-base responses. The present findings reinforce the need for practioners to look beyond the classification of RE workouts when aiming to elicit specific physiological responses.