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H Hauner

Publications and source records attributed to H Hauner.

At least 145 records · Page 8Linked to original sources
PubMed1989

Adipogenic activity in sera from obese children before and after weight reduction.

The adipogenic and mitogenic potentials of sera obtained from obese children before and after weight reduction and from lean control subjects were studied in clonal 3T3 L1 fibroblasts. The sera from the lean (n = 14) and obese (n = 12) children under habitual diet contained similar adipogenic activity. However, when the obese children underwent a weight-reduction program for 3 wk (600 kcal/d), the potential of their sera to stimulate glycero-phosphate dehydrogenase, an index of adipogenic activity, was significantly reduced by 32% (p less than 0.01). Similarly, the mitogenic activity of these sera decreased significantly (202 +/- 15 vs 231 +/- 27 micrograms per dish, p less than 0.01). Testing pooled sera from the different groups in cultured rat adipocyte precursor cells gave similar results. This study suggests that human childhood-onset obesity is not accompanied by increased circulatory factors involved in the formation of new fat cells. The adipogenic and mitogenic activity of sera from obese children may be influenced by long-term dietary restriction.

Adipose Tissue↗
PubMed1989

Promoting effect of glucocorticoids on the differentiation of human adipocyte precursor cells cultured in a chemically defined medium.

Stromal-vascular cells obtained from adult human subcutaneous adipose tissue were cultured in a chemically defined serum-free medium. In the presence of 0.2 nM triiodothyronine and 0.5 microM insulin, up to 25% of the cells were able to undergo terminal adipose differentiation within 18 d, as assessed by lipid accumulation and the expression of lipoprotein lipase (LPL) and glycerol-3-phosphate dehydrogenase (GPDH) activities. Addition of cortisol resulted in a potent dose-dependent stimulation of the adipose differentiation process. Cortisol could be replaced by dexamethasone and partly by aldosterone, but not by sex steroids. The proportion of differentiated cells was dependent upon the age of the donor; when isolated from young adults, up to 70% of the stromal-vascular cells expressed the adipocyte phenotype as compared with 5-10% when the cells were isolated from the oldest subjects. An inverse relationship was observed between the age of the 27 normal-weight donors and the extent of GPDH expression after maintenance of the cells for 18 d in chemically defined medium supplemented with insulin, triiodothyronine, and cortisol (r = -0.787, P less than 0.001). It is concluded that adult human adipose tissue still contains precursor cells that are able to undergo adipose differentiation in vitro. This improved culture system may offer the opportunity to characterize other adipogenic factors as well as antiadipogenic factors involved in the control of adipose tissue growth.

Adipose Tissue↗
PubMed1988

[Relation between body fat distribution, insulin levels and glucose tolerance in obese females].

Relationship between body fat distribution, serum insulin, and glucose tolerance in obese, non-diabetic women. Recent studies suggest that hyperinsulinemia and upper body obesity are predictive factors for the development of non-insulin-dependent diabetes mellitus. To further characterize the relationship between body fat distribution, serum insulin, and glucose tolerance an oral glucose tolerance test was performed in 48 obese, non-diabetic women. Fasting insulin levels were correlated to both total body fat calculated as body mass index (r = 0.58, p less than 0.001) and upper body fat distribution expressed as waist-to-hip ratio (WHR, r = 0.47, p less than 0.01). In the women with upper body fat localization (WHR greater than 0.90) significantly higher basal and glucose-stimulated insulin concentrations were established than in the women with a lower body type of obesity (WHR less than 0.78) (basal insulin 27.4 +/- 11.5 vs. 15.4 +/- 8.8 mU/l, p less than 0.05, insulin area 779 +/- 320 vs. 468 +/- 237 U, p less than 0.05). They also had impaired glucose tolerance (glucose area 925 +/- 139 vs. 633 +/- 147 U, p less than 0.01). Fasting triglyceride concentrations were correlated both with WHR (r = 0.63, p less than 0.001) and fasting insulin (r = 0.33, p less than 0.05) but not with BMI (r = -0.02, n.s.). A positive association was found between systolic and diastolic blood pressure and both WHR (r = 0.43 and r = 0.44 resp., p less than 0.01) and BMI (each r = 0.35, p less than 0.05). Interestingly, basal insulin was also associated with blood pressure (r = 0.30, p less than 0.1, and r = 0.40, p less than 0.01 resp.).(ABSTRACT TRUNCATED AT 250 WORDS)

Adipose Tissue↗
PubMed1988

Effect of vasoactive intestinal polypeptide (VIP) on glucose and lipid metabolism of isolated rat adipocytes.

The biologic actions of vasoactive intestinal polypeptide (VIP) on insulin binding, glucose uptake and utilization, and on lipolysis were studied. At concentrations between 10(-10) and 10(-7) mol/l VIP influenced neither glucose uptake nor glucose incorporation into lipids under basal and insulin-stimulated conditions. This effect was independent of the presence of adenosine deaminase in the incubation medium. At 10(-8) mol/l VIP increased insulin binding affinity slightly but not significantly, shifting the ID-50 from 12.4 ng/ml to 10.3 ng/ml, without any change in receptor number. However, VIP showed a marked dose-dependent lipolytic activity with the lowest effective concentration at 10(-9) mol/l. At 10(-6) mol/l glycerol release increased 7.3-fold as compared to basal lipolysis. In conclusion, VIP did not affect adipose tissue metabolism at physiologic concentrations. In the rare Verner-Morrison syndrome, however, the potent lipolytic activity of VIP may contribute to the metabolic disturbances observed.

Adipose Tissue↗
PubMed1988

Fat distribution, endocrine and metabolic profile in obese women with and without hirsutism.

The relationship between adipose tissue distribution, androgen levels, and metabolic complications of obesity was studied in 20 hirsute and 20 nonhirsute obese premenopausal women. The group of hirsute women showed preferentially an upper body type of obesity as assessed by the waist-to-hip ratio (0.902 + 0.017 v 0.778 +/- 0.015, P less than .01). They had higher serum concentrations of total testosterone (100.4 + 11.7 v 48.8 +/- 4.5 ng/dL, P less than .01) and lower levels of serum sex-hormone-binding globulin (28.1 +/- 3.6 v 44.0 + 4.2 nmol/L, P less than .05) exhibiting an increased androgenic activity as compared to the nonhirsute women. Serum glucose and insulin levels after an oral glucose load were significantly higher in the hirsute women. In addition, the group of hirsute females has significantly higher fasting concentrations of total cholesterol (5.82 +/- 0.28 v 4.75 +/- 0.14 mmol/L, P less than .05) and triglycerides (2.51 +/- 0.38 v 1.14 +/- 0.10 mmol/L, P less than .01). The hirsute group also showed higher systolic (166.7 +/- 5.1 v 142.1 +/- 4.5 mm Hg, P less than .01) and diastolic (100.9 +/- 3.6 v 85.2 +/- 2.5 mm Hg, P less than .01) blood pressure values than the nonhirsute women. Analysis of correlation revealed that an increasing waist-to-hip ratio was accompanied by increasing testosterone levels (r = .39, P less than .05) and by decreasing sex-hormone-binding globulin levels (r = .37, P less than .05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adipose Tissue↗
PubMed1988

Endogenous opiates do not influence glucose and lipid metabolism in rat adipocytes.

The effects of the opiates beta-endorphin, dynorphin, met-enkephalin, leu-enkephalin, morphine and of the opiate-antagonist naloxone on glucose metabolism and lipolysis were studied in isolated rat adipocytes. None of the tested substances was found to alter 125I-Insulin binding. The opiates did not influence 2-deoxy-glucose uptake or glucose incorporation into lipids. They also did not exhibit a lipolytic activity. We conclude that the disturbances of glucose homeostasis induced by endogenous opiates are not mediated by an effect on peripheral glucose metabolism.

Adipose Tissue↗
PubMed1988

Effects of gastric inhibitory polypeptide on glucose and lipid metabolism of isolated rat adipocytes.

The effects of gastric inhibitory polypeptide (GIP) on glucose and lipid metabolism of isolated rat adipocytes were investigated. In a dose-dependent manner, GIP stimulated 2-deoxy-glucose uptake increasing the glucose transport rate by up to 140% at a concentration of 10(-7) mol/l. GIP also stimulated the conversion of 14C-glucose into extractable lipids by up to 81% at 10(-7) mol/l. Insulin-stimulated 2-deoxy-glucose uptake and lipogenesis were additively enhanced by the presence of GIP. Insulin binding was slightly but not significantly increased by addition of GIP, mainly due to an increase in receptor affinity. GIP had a weak lipolytic activity, but lipolysis elicited by glucagon or isoproterenol was potently reduced. In conclusion, independent of its insulinotropic action, GIP showed a insulin-like activity on glucose metabolism and lipolysis in rat adipose tissue. The possible role of GIP for the development of obesity is discussed.

Adipose Tissue↗
PubMed1988

Differentiation of adipocyte precursor cells from obese and nonobese adult women and from different adipose tissue sites.

We studied adipocyte development in primary cultures of stromal-vascular cells from the adipose tissue of obese and nonobese adult women. Adipose conversion was promoted by addition to confluent cultures of 10(-9) mol/l insulin, 10(-7) mol/l cortisol and for the first two days 0.5 mmol/l 1-methyl-3-isobutylxanthine (MIX). Presence of MIX for a longer period resulted in an increasing differentiation rate. No significant difference in the number of developing fat cells was observed between cultures from 8 obese (body mass index 33.6 +/- 4.1 kg/m2) and from 6 lean (body mass index 22.3 +/- 2.4 kg/m2) adults (390 +/- 102 vs. 354 +/- 85 fat cells/cm2, n.s.). The number of new fat cells obtained in cultures from the subcutaneous fat depot was significantly higher as compared to those obtained in cultures from the intraabdominal fat region (360 +/- 68 vs. 79 +/- 35 fat cells/cm2, p less than 0.01), suggesting the existence of regional variations in the differentiation capacity of adipocyte precursor cells.

Adipose Tissue↗
PubMed1987

Adipose tissue development: the role of precursor cells and adipogenic factors. Part I: Adipose tissue development and the role of precursor cells.

Obesity is regarded as a heterogeneous syndrome, which may appear in different forms. Various causes have been found to contribute to its pathogenesis. During recent years investigations of adipose tissue cellularity and its dynamic changes have gained growing interest. An important progress was the discovery of adipose tissue precursor cells. These cells have not yet been precisely identified by morphological and biochemical methods in intact tissue. However, due to methodological developments such precursor cells can be cultured both as primary cultures and as established cell lines. These culture systems have proven to be valuable models for the study of the processes involved in the formation of new fat cells.

Adipose Tissue↗
PubMed1987

Adipose tissue development: the role of precursor cells and adipogenic factors. Part II: The regulation of the adipogenic conversion by hormones and serum factors.

Cell culture systems have proven to be valuable models for the study of the processes involved in the formation of new fat cells. Two separate steps may be distinguished in adipocyte development. First, the determination of a mesenchymal stem cell into a preadipocyte, second, its conversion into a mature fat cell. In cloned cell lines adipose conversion depends on at least one postconfluent mitosis possibly induced by insulin-like growth factors or by as yet unknown mitogens. In addition growth hormone, glucocorticoids, and insulin are needed for conversion to take place. The adipose conversion of preadipocytes originating from the stromal vascular fraction of adipose tissue does not depend on postconfluent mitoses and needs only insulin and glucocorticoid hormones in physiological concentrations. However, the ability to undergo adipose conversion is not stable in these cells, but gets lost after repeated subcultures or seeding at low densities. In addition to stimulating hormones an increasing number of factors inhibiting the conversion process have also been detected, the physiological function of which remains unclear at the moment.

Adipose Tissue↗
PubMed1987

[Distribution of adipose tissue and complications of obesity in overweight women with and without hirsutism].

A correlation between the serum androgen levels and the distribution pattern of adipose tissue as well as occurrence of complications of obesity were investigated in 24 obese women with and without hirsutism. The hirsute women (n = 12) displayed higher androgen levels than the women without hirsutism (n = 12) of the same age and weight and possessed a more abdominally pronounced distribution of adipose tissue measured as the quotient of waist and hip circumference (0.87 +/- 0.08 as compared to 0.76 +/- 0.06; P less than 0.05). In addition, the overweight women with hirsutism had higher fasting triglyceride levels as well as higher values of systolic and diastolic blood pressure. Overall, a positive correlation was found between testosterone and the ratio of waist and hip circumference (r = 0.40; P less than 0.05) and the values of diastolic blood pressure (r = 0.51; P less than 0.01). Moreover, the ratio of waist and hip circumference correlated with the systolic blood pressure values (r = 0.61; P less than 0.001), the fasting triglyceride levels (r = 0.42; P less than 0.05) as well as the basal insulin concentration (r = 0.48; P less than 0.05). These results are an indication that raised androgens predispose to accumulation of fat in the abdominal region. In turn, an android distribution of adipose tissue is associated with more frequent metabolic disorders and vascular hypertension.

Adipose Tissue↗
PubMed1987

Glucocorticoids and insulin promote the differentiation of human adipocyte precursor cells into fat cells.

To study the in vitro differentiation of human adipocyte precursor cells and its regulation by hormones, primary cultures of stromal vascular cells of human adipose tissue were established. A 30- to 70-fold increase in the number of developing fat cells was achieved by the addition of cortisol or related corticosteroids in the presence of insulin. Either of the two hormones alone was ineffective. The stimulatory action of cortisol was dose dependent and occurred at physiological concentrations. The results suggest that glucocorticoids may play a role in the development of human hyperplastic obesity by stimulating the formation of adipocytes from precursor cells.

Adipose Tissue↗
PubMed1986

Adipogenic factors in human serum promote the adipose conversion of 3T3-L1 fibroblasts.

The adipose conversion of 3T3-L1 fibroblasts to fully developed adipocytes depends on the presence of serum in the culture medium. This study demonstrates that human serum or plasma also effectively promote the adipose conversion of 3T3-L1 cells. At rising serum concentrations this effect is abolished however by the presence of antiadipogenic factors. Sera of newborns contained the highest adipogenic activity, approximately 1.8-fold higher than sera from lean adults. This difference is probably due to higher growth hormone (GH) concentrations. Adipogenic activity in sera from obese adults under reduction diet and in sera from older persons did not differ from that found in sera from lean young adults. Complete elimination of GH was achieved by heat treatment and ethanol precipitation. About 40-60 percent of the adipogenic activity in serum samples from adults and more than 70 percent of the activity in sera from newborns is due to GH. The remaining adipogenic activity was partially purified by gel chromatography at acidic pH. We conclude from these results that human serum contains at least two adipogenic factors: GH and a heat- and acid-stable low-molecular-weight component.

Adipose Tissue↗