Is genetically transmitted obesity due to an adipose tissue defect?

1979 ◽  
Vol 205 (1160) ◽  
pp. 395-410 ◽  
Keyword(s):  
Cell Size ◽  
Fat Cells ◽  
Obese Mice ◽  
Fat Transplantation ◽  
Fat Cell ◽  
Factors Associated ◽  
Gold Thioglucose ◽  
Immunological Rejection ◽  
Negligible Contribution

1. The aim of this investigation was to ascertain of a variety of obese rodents whether the primary cause of fat cell enlargement lay in the fat cell itself, or in its environment. Rodents studied were the mutant mice ‘diabetic’ ( db / db ), ‘adipose’ ( db ad / db ad ), and ‘yellow obese’ ( A v / + ), New Zealand obese mice, CBA mice made obese with gold thioglucose, and obese BIO 4.24 hamsters. 2. Gonadal fat of obese or lean genotype was transplanted under the kidney capsule of an obese or lean host. Grafts were left in place for at least one month, then examined histologically to measure fat cell diameters, from which fat cell masses were calculated. 3. Immunological rejection of grafts was avoided either by using mice syngeneic except for the obesity producing mutation ( db / db , db ad / db ad or A v / + ) or by transplanting into F 1 hybrids (NZO x BALB/c) made by mating the strains acting as donors of obese or lean fat. Transplantation of fat between lean BIO 4.22 hamsters and obese BIO 4.24 hamsters was possible because these had common histocompatability antigens. 4. In all the forms of murine obesity studied, ‘lean’ fat cells enlarged in an obese recipient to the size typical of cells in ‘obese’ fat whilst ‘obese’ fat cells shrunk in a lean recipient to, at least, the size typical of ‘lean’ fat. Lean hamster fat cells also enlarged in an ‘obese’ environment and ‘obese ’ hamster cells shrunk in a 'lean’ environment. 5. Environment therefore contributes to the determination of fat cell size in all the rodents studied, and in several rodents ( db / db , db ad / db ad , A v / + , and gold thioglucose obese mice) our results showed that environmental factors are of paramount importance in determining cell size, and factors associated with the fat cell itself make a negligible contribution.

Water content of rat adipose tissue and isolated adipocytes in relation to cell size

1976 ◽  
Vol 231 (5) ◽  
pp. 1568-1572 ◽  
Author(s):  
M DiGirolamo ◽  
JL Owens
Keyword(s):  
Adipose Tissue ◽  
Water Content ◽  
Cell Volume ◽  
Cell Size ◽  
Intracellular Water ◽  
Male Rats ◽  
Fat Cells ◽  
Fat Cell ◽  
Tissue Water ◽  
Adipose Mass

Epididymal adipose tissue composition and adipocyte water content were studied in male rats during growth and development of spontaneous obesity. The data show that a highly significant positive correlation exists between fat-cell volume and intracellular water space (IWS) (r=.967, P less than .001). Intracellular water, expressed as picoliters per fat cell, varied from 1.5-2 in small fat cells (mean vol, 30-50 pl) to 9-10 in large cells (800-1,000 pl). When expressed as percent of fat-cell volume, IWS varied from 5-7% in the small fat cells to 1-1.3% in the large ones. Total adipose tissue water continued to increase with increasing adipose mass. Similarly, total adipocyte water increased with enlarging cell size and tissue mass. The contribution of total adipocyte water (as contrasted to that of nonadipocyte water) to total tissue water, however, was found to be limited (less than 23%) and to decline progressively with adipose mass expansion.

Regional variation in HDL metabolism in human fat cells: effect of cell size

1987 ◽  
Vol 252 (5) ◽  
pp. E654-E659 ◽  
Author(s):  
J. P. Despres ◽  
B. S. Fong ◽  
P. Julien ◽  
J. Jimenez ◽  
A. Angel
Keyword(s):  
Cell Size ◽  
Cellular Uptake ◽  
Plasma Membranes ◽  
Cholesterol Content ◽  
Cholesterol Concentration ◽  
Fat Cells ◽  
Obese Patients ◽  
Adipocyte Size ◽  
Fat Cell ◽  
Omental Fat

Abdominal obesity is related to reduced plasma high-density lipoprotein (HDL) cholesterol, and both are associated with cardiovascular disease risk. We have observed that plasma membranes from abdominal subcutaneous adipocytes have a greater HDL binding capacity than omental fat cell plasma membranes. The present study examined whether these binding characteristics could be due to differences in fat cell size or cholesterol concentration between the two adipose depots. Abdominal subcutaneous and deep omental fat were obtained from massively obese patients at surgery. Subcutaneous abdominal fat cells were significantly larger and their cellular cholesterol content greater than omental adipocytes. The uptake of HDL by collagenase-isolated fat cells was studied by incubating the cells for 2 h at 37 degrees C with 10 micrograms/ml 125I-HDL2 or 125I-HDL3. In both depots, the cellular uptake of 125I-HDL2 and 125I-HDL3 was specifically inhibited by addition of 25-fold excess unlabeled HDL and a close correlation was observed between the cellular uptake of 125I-HDL2 and 125I-HDL3. In obese patients, the uptake of 125I-HDL was higher in subcutaneous cells than in omental cells [5.85 +/- 0.53 vs. 2.74 +/- 0.30 pmol X 2 h-1. (10(6) cells)-1]. The cellular 125I-HDL uptake was significantly correlated with adipocyte size and fat cell cholesterol content but not with adipocyte cholesterol concentration. These results suggest that the higher HDL uptake observed in subcutaneous cells compared with omental cells in obesity is the result of differences in adipocyte size rather than differences in the cholesterol concentration (cholesterol-to-triglyceride ratio).(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Methionine requirement of kittens given amino acid diets containing adequate cystine

1983 ◽  
Vol 49 (3) ◽  
pp. 411-417 ◽  
Author(s):  
Katherine A. Smalley ◽  
Quinton R. Rogers ◽  
James G. Morris
Keyword(s):  
Adipose Tissue ◽  
Cell Size ◽  
Muscle Tissue ◽  
Dna Content ◽  
Shoulder Joint ◽  
Subcutaneous Adipose Tissue ◽  
Fat Cells ◽  
Fat Cell ◽  
Fat Cell Size ◽  
Subcutaneous Adipose

1. The effects of feeding either high-protein (HP) or low-protein (LP) diets between 1.8 and 15 kg live weight (LW) and a low-energy (LE) or high-energy (HE) intake subsequently on the cellularity of muscle and adipose tissue in pigs growing to 75 kg LW were investigated.2. The effects of the nutritional treatments on muscle tissue were assessed from the weight and DNA content of the m. adductor. For adipose tissue the total DNA content and fat cell size of the subcutaneous adipose tissue contained in the left shoulder joint were determined.3. Feeding the LP diets in early life reduced the weight and DNA content of the m. adductor (P < 0.01) and increased fat cell size (P < 0.01) at 15 kg LW.4. Subsequent to 15 kg there was an almost linear increase in muscle DNA with increasing LW, and the difference between pigs from the initial protein treatments progressively diminished and was no longer apparent at 60 kg LW.5. At 30 kg LW, pigs given the LP diets before 15 kg LW contained less DNA in the subcutaneous adipose tissue from the shoulder joint (P < 0.01) and had larger fat cells (P < 0.05) than pigs given the HP diets initially. However, adipose DNA and fat cell size increased with increasing LW and the differences resulting from the initial protein treatments progressively diminished. On the LE and HE treatments subsequent to 15 kg these differences were no longer evident at 45 and 60 kg respectively.6. Pigs given the HE intake subsequent to 15 kg, contained less DNA in muscle tissue (P < 0·05) at 60 and 75 kg LW and had larger fat cells (P < 0·05) at 45, 60 and 75 kg LW, than pigs on the LE treatment.

Cold-induced developmental changes in fat cell size and number in brown adipose tissue of the rat

1981 ◽  
Vol 240 (4) ◽  
pp. E379-E383 ◽  
Author(s):  
C. Senault ◽  
G. Cherqui ◽  
M. Cadot ◽  
R. Portet
Keyword(s):  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
Cold Acclimation ◽  
Cell Size ◽  
Brown Fat ◽  
Control Group ◽  
Fat Cells ◽  
Fat Cell ◽  
Brown Adipose ◽  
The Mean

Seven-week-old Long-Evans rats were acclimated to a constant temperature of either 28 degrees C (control group) or 5 degrees C (cold-acclimated group). Cold acclimation induced a 70% increase in the interscapular brown adipose tissue (IBAT) relative mass, a 35% increase in DNA content, and a 44% decrease in triglyceride (TG) content, which resulted in a 51% decrease of the TG/DNA ratio. A procedure is described by which brown fat cells were isolated, with a yield of 21% from the IBAT of the control group and of 38% in the cold-acclimated group. In both groups, the brown fat cells accounted for 35-37% of the total cells in the tissue. Cold acclimation induced decreases in the mean fat cell diameter (about 20%), the mean fat cell TG content (50%), and the fat cell TG/DNA ratio (50%). The total number of IBAT fat cells was significantly increased in cold-acclimated rats. It is concluded that cold acclimation involves a hyperplasia of the IBAT, associated with a decrease of fat cell size without any alteration of the fat cell-to-nonfat cell ratio.

Adipocyte insulin resistance: effects of aging, obesity, exercise, and food restriction

1987 ◽  
Vol 62 (1) ◽  
pp. 95-100 ◽  
Author(s):  
B. W. Craig ◽  
S. M. Garthwaite ◽  
J. O. Holloszy
Keyword(s):  
Insulin Resistance ◽  
Cell Size ◽  
Food Restriction ◽  
Glucose Oxidation ◽  
Fat Cells ◽  
Fat Cell ◽  
Fat Cell Size ◽  
Cell Hypertrophy ◽  
Insulin Responsiveness ◽  
Effects Of Aging

This study examined the effects of aging, exercise training, and food restriction on epididymal fat cell size and resistance to insulin in rats. The exercise group was given access to voluntary running wheels at age 6 mo. The rats were studied at ages 12 and 28 mo. Sedentary free-eating (SFE) rats were obese and their fat cells were extremely insulin resistant, showing minimal increases in glucose oxidation and 2-deoxy-D-glucose (2-DOG) uptake in response to high insulin concentrations. The runners' adipocytes were smaller and had a greater responsiveness to insulin (approximately 9-fold for 2-DOG uptake and approximately 30-fold for glucose oxidation) than those of the SFE rats. Sedentary rats that were food restricted to keep their body weights the same as those of the runners had fat cells that were intermediate both in size and insulin responsiveness relative to those of the SFE rats and runners. There was a close correlation between fat cell size and responsiveness to insulin of 2-DOG uptake and glucose oxidation independent of age. There were no significant differences in fat cell size, insulin sensitivity, or insulin responsiveness between the adult (12 mo) and old (28 mo) rats in the same treatment groups. We conclude that aging alone has little or no effect on the responsiveness to insulin of glucose metabolism in fat cells and that the insulin resistance of adipocytes from obese older rats is due to fat cell hypertrophy, not aging. Exercise is effective in protecting against development of fat cell hypertrophy and insulin resistance.

scholarly journals Comparison of Hormone-Sensitive Lipase Activity in Visceral and Subcutaneous Human Adipose Tissue1

1997 ◽  
Vol 82 (12) ◽  
pp. 4162-4166
Author(s):  
Signy Reynisdottir ◽  
Michèle Dauzats ◽  
Anders Thörne ◽  
Dominique Langin
Keyword(s):  
Cell Size ◽  
Ribonucleic Acid ◽  
Hormone Sensitive Lipase ◽  
Fat Cells ◽  
Fat Cell ◽  
Messenger Ribonucleic Acid ◽  
Fat Cell Size ◽  
Wide Range ◽  
Hormone Sensitive

The possible role of hormone-sensitive lipase (HSL) in determining regional differences in lipolysis activation in humans was studied in vitro. Small adipose tissue biopsies were obtained from the abdominal sc and omental regions during surgery in 21 subjects spanning a wide range of body mass index (22–50 kg/m2). In lipolysis experiments, isolated fat cells were incubated with lipolytic agents acting at different levels in the lipolytic cascade. The activity and messenger ribonucleic acid expression of HSL were determined. The maximum lipolytic capacity was higher in sc than in omental fat cells as were HSL activity and messenger ribonucleic acid expression. The maximum lipolysis rate was significantly correlated to HSL activity. This is in accordance with the role of HSL as the rate-limiting step of lipolysis. However, adipocytes were 24% larger in the sc than in the omental region, and the lipolysis rate was significantly correlated to fat cell size regardless of either the region of origin or gender. This indicates that the regulation of HSL activity in healthy subjects, which appears to occur at a transcriptional level, is to a large extent dependent on fat cell size.

Effects of stopping training on size and response to insulin of fat cells in female rats

1983 ◽  
Vol 54 (2) ◽  
pp. 571-575 ◽  
Author(s):  
B. W. Craig ◽  
K. Thompson ◽  
J. O. Holloszy
Keyword(s):  
Cell Size ◽  
Glucose Oxidation ◽  
Close Correlation ◽  
Female Rats ◽  
Fat Cells ◽  
Adipocyte Size ◽  
Fat Cell ◽  
Fat Cell Size ◽  
Wide Range ◽  
Initial Difference

The parametrial adipocytes of exercise-trained female rats were smaller and had greater rates of 2-deoxyglucose uptake and glucose oxidation over a wide range of insulin concentrations than the fat cells of sedentary animals of the same age. The fat cells of the sedentary animals had a 180% greater volume than those of the trained rats, despite only a 9% difference in body weight. Following cessation of training adipocyte size increased rapidly; approximately two-thirds of the initial difference in fat cell volume between the trained and sedentary rats had disappeared after 9 days without exercise. Concomitant with the increase in fat cell size, the response of 2-deoxyglucose uptake and glucose oxidation to insulin diminished. There was a close correlation between fat cell size and the magnitude of the response to insulin of both glucose oxidation and 2-deoxyglucose uptake. It appears from these results that the effect of exercise training on the response of adipocytes to insulin is rapidly lost when exercise is stopped.

Autologous Fat Transplantation: An Evaluation of Microcalcification and Fat Cell Survivability following (AFT) Cosmetic Breast Augmentation

1988 ◽  
Vol 5 (4) ◽  
pp. 283-288 ◽  
Author(s):  
Mel Bircoll
Keyword(s):  
Breast Carcinoma ◽  
Breast Augmentation ◽  
Survival Rates ◽  
Fat Cells ◽  
Fat Transplantation ◽  
Fat Cell ◽  
Autologous Fat ◽  
Autologous Fat Transplantation ◽  
Considerable Controversy ◽  
And Control

Since my introduction of the concept and techniques of autologous fat transplantation, considerable controversy has arisen over the amount of fat cell survivability and the possible formation of microcalcifications interfering with the diagnosis of breast carcinoma. An analysis of 5 years of experience using AFT in breast augmentation is presented. Maximum survival rates of fat cells exceed 80% and the incidence and control of microcalcification is discussed.

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