Quantitation of inhibitory G-proteins in fat cells of obese and normal-weight human subjects

1994 ◽  
Vol 1201 (1) ◽  
pp. 69-75 ◽  
Author(s):  
J KAARTINEN ◽  
K LANOUE ◽  
J OHISALO
Keyword(s):  
G Proteins ◽  
Human Subjects ◽  
Normal Weight ◽  
Fat Cells

Heart rate variability and baroreflex sensitivity are reduced in chronically undernourished, but otherwise healthy, human subjects

2003 ◽  
Vol 104 (3) ◽  
pp. 295-302 ◽  
Author(s):  
Mario VAZ ◽  
A.V. BHARATHI ◽  
S. SUCHARITA ◽  
D. NAZARETH
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
High Frequency ◽  
Baroreflex Sensitivity ◽  
Human Subjects ◽  
Normal Weight ◽  
Autonomic Nerve ◽  
Total Power ◽  
Healthy Human ◽  
Frequency Power

Alterations in autonomic nerve activity in subjects in a chronically undernourished state have been proposed, but have been inadequately documented. The present study evaluated heart rate and systolic blood pressure variability in the frequency domain in two underweight groups, one of which was undernourished and recruited from the lower socio-economic strata [underweight, undernourished (UW/UN); n = 15], while the other was from a high class of socio-economic background [underweight, well nourished (UW/WN); n = 17], as well as in normal-weight controls [normal weight, well nourished (NW/WN); n = 27]. Baroreflex sensitivity, which is a determinant of heart rate variability, was also assessed. The data indicate that total power (0–0.4Hz), low-frequency power (0.04–0.15Hz) and high-frequency power (0.15–0.4Hz) of RR interval variability were significantly lower in the UW/UN subjects (P<0.05) than in the NW/WN controls when expressed in absolute units, but not when the low- and high-frequency components were normalized for total power. Baroreflex sensitivity was similarly lower in the UW/UN group (P<0.05). Heart rate variability parameters in the UW/WN group were generally between those of the UW/UN and NW/WN groups, but were not statistically different from either. The mechanisms that contribute to the observed differences between undernourished and normal-weight groups, and the implications of these differences, remain to be elucidated.

scholarly journals Acute effects of mustard, horseradish, black pepper and ginger on energy expenditure, appetite,ad libitumenergy intake and energy balance in human subjects

2012 ◽  
Vol 109 (3) ◽  
pp. 556-563 ◽  
Author(s):  
N. T. Gregersen ◽  
A. Belza ◽  
M. G. Jensen ◽  
C. Ritz ◽  
C. Bitz ◽  
...  
Keyword(s):  
Energy Balance ◽  
Treatment Effects ◽  
Human Subjects ◽  
Statistical Significance ◽  
Black Pepper ◽  
Normal Weight ◽  
Acute Effects ◽  
Significant Treatment ◽  
Ad Libitum ◽  
Few Data

Chilli peppers have been shown to enhance diet-induced thermogenesis (DIT) and reduce energy intake (EI) in some studies, but there are few data on other pungent spices. The primary aim of the present study was to test the acute effects of black pepper (pepper), ginger, horseradish and mustard in a meal on 4 h postprandial DIT. The secondary aim was to examine the effects on subjective appetite measures,ad libitumEI and energy balance. In a five-way placebo-controlled, single-blind, cross-over trial, twenty-two young (age 24·9 (sd4·6) years), normal-weight (BMI 21·8 (sd2·1) kg/m2) males were randomly assigned to receive a brunch meal with either pepper (1·3 g), ginger (20 g), horseradish (8·3 g), mustard (21 g) or no spices (placebo). The amounts of spices were chosen from pre-testing to make the meal spicy but palatable. No significant treatment effects were observed on DIT, but mustard produced DIT, which tended to be larger than that of placebo (14 %, 59 (se3)v.52 (se2) kJ/h, respectively,P= 0·08). No other spice induced thermogenic effects approaching statistical significance. Subjective measures of appetite (P>0·85),ad libitumEI (P= 0·63) and energy balance (P= 0·67) also did not differ between the treatments. Finally, horseradish decreased heart rate (P= 0·048) and increased diastolic blood pressure (P= 0·049) compared with placebo. In conclusion, no reliable treatment effects on appetite, EI or energy balance were observed, although mustard tended to be thermogenic at this dose. Further studies should explore the possible strength and mechanisms of the potential thermogenic effect of mustard actives, and potential enhancement by, for example, combinations with other food components.

Mining possible associations of faecal A. muciniphila colonisation patterns with host adiposity and cardiometabolic markers in an adult population

2019 ◽  
Vol 10 (7) ◽  
pp. 741-749 ◽  
Author(s):  
E.K. Mitsou ◽  
M. Detopoulou ◽  
A. Kakali ◽  
E. Fragopoulou ◽  
T. Nomikos ◽  
...  
Keyword(s):  
Human Subjects ◽  
Adult Population ◽  
Fasting Blood Glucose ◽  
Density Lipoprotein ◽  
Positive Association ◽  
Interleukin 10 ◽  
Normal Weight ◽  
Lipoprotein Cholesterol ◽  
Negatively Associated ◽  
Cardiometabolic Markers

We aimed to evaluate colonisation patterns of Akkermansia muciniphila in a Greek adult population and to investigate model-adjusted associations of A. muciniphila with host adiposity and cardiometabolic markers. Participants (n=125) underwent anthropometric, dietary, physical activity and lifestyle evaluation. Blood sampling for determination of blood lipid indices, glucose metabolism, adiponectin, lipoprotein-associated phospholipase A2 (Lp-PLA2), inflammation and oxidative stress parameters was also performed. Stool A. muciniphila presence and levels were determined by quantitative PCR and subjects were grouped based on bimodal distribution of levels (Low vs High). A. muciniphila was detected in 88.6% of participants. Overweight/obese (OW/OB) subjects were more prone in low bimodal levels of A. muciniphila compared to normal-weight (NW) individuals (58.75 vs 27.59%, P=0.004), with a 4-time greater likelihood after multi-adjusted logistic regression analysis (P=0.016). Levels of A. muciniphila were negatively associated with total cholesterol/high-density lipoprotein cholesterol (TC/HDL-C) ratio (log10:-0.009±0.004, P=0.033), whereas detection of this bacterium was negatively associated with both TC/HDL-C ratio (log10: -0.049±0.023, P=0.036) and low-density lipoprotein cholesterol/HDL-C ratio (-0.407±0.176, P=0.023). Furthermore, low bimodal levels of A. muciniphila were positively associated with fasting blood glucose (log10: 0.018±0.009, P=0.037). In terms of inflammation markers, levels of A. muciniphila were positively associated with soluble cluster of differentiation-14 (sCD14) (log10: 0.012±0.004, P=0.003) and faecal detection of this bacterium had a positive association with anti-inflammatory interleukin 10 levels (log10: 0.325±0.131, P=0.015). In addition, A. muciniphila levels were positively associated with total adiponectin (log10: 0.046±0.015, P=0.002), whereas low bimodal levels of A. muciniphila had an inverse relationship with this blood marker (log10: -0.131±0.053, P=0.016). In conclusion, we confirmed the previously reported association of A. muciniphila with metabolic health for the first time in a Greek urban population; furthermore, we shed some light to novel atherosclerotic risk markers with rather unexplored connections with A. muciniphila colonisation patterns in human subjects.

scholarly journals Circulating vaspin and visfatin are not affected by acute or chronic energy deficiency or leptin administration in humans

2011 ◽  
Vol 164 (6) ◽  
pp. 911-917 ◽  
Author(s):  
Eun Seok Kang ◽  
Faidon Magkos ◽  
Elizabeth Sienkiewicz ◽  
Christos S Mantzoros
Keyword(s):  
Human Subjects ◽  
Normal Weight ◽  
Hypothalamic Amenorrhea ◽  
Energy Deficiency ◽  
Chronic Energy Deficiency ◽  
Before And After ◽  
Term Energy ◽  
Energy Deprivation

ObjectiveAnimal and in vitro studies indicate that leptin alleviates starvation-induced reduction in circulating vaspin and stimulates the production of visfatin. We thus examined whether vaspin and visfatin are affected by short- and long-term energy deprivation and leptin administration in human subjects in vivo.Design and methodsWe measured circulating levels of vaspin and visfatin i) before and after 72 h of starvation (leading to severe hypoleptinemia) with or without leptin administration in replacement doses in 13 normal-weight subjects, ii) before and after 72 h of starvation with leptin administration in pharmacological doses in 13 lean and obese subjects, iii) during chronic energy deficiency in eight women with hypothalamic amenorrhea on leptin replacement for 3 months, and iv) during chronic energy deficiency in 18 women with hypothalamic amenorrhea on leptin replacement or placebo for 3 months.ResultsAcute starvation decreased serum leptin to 21% of baseline values, (P=0.002) but had no significant effect on vaspin and visfatin concentrations (P>0.05). Nor did normalization of leptin levels affect the concentrations of these two adipokines (P>0.9). Leptin replacement in women with hypothalamic amenorrhea did not significantly alter vaspin and visfatin concentrations, whether relative to baseline or placebo administration (P>0.25). Pharmacological doses of leptin did not affect circulating vaspin and visfatin concentrations (P>0.9).ConclusionsCirculating vaspin and visfatin are not affected by acute or chronic energy deficiency leading to hypoleptinemia and are not regulated by leptin in human subjects, indicating that these adipocyte-secreted hormonal regulators of metabolism are independently regulated in humans.

scholarly journals The acute effect of D-tagatose on food intake in human subjects

2000 ◽  
Vol 84 (2) ◽  
pp. 227-231 ◽  
Author(s):  
Benjamin Buemann ◽  
Søren Toubro ◽  
Anne Raben ◽  
John Blundell ◽  
Arne Astrup
Keyword(s):  
Food Intake ◽  
Energy Intake ◽  
Human Subjects ◽  
Acute Effect ◽  
Normal Weight ◽  
Double Blind ◽  
Breakfast Meal ◽  
Ad Libitum ◽  
Osmotic Effects ◽  
Randomized Crossover Study

A double-blind randomized crossover study was performed with nineteen normal-weight men to investigate the effect on subsequent ad libitum food intake of replacing 29 g sucrose with 29 g D-TAGATOSE AS SWEETENER TO A BREAKFAST MEAL. d-Tagatose is a malabsorbed stereoisomer of fructose with potential application as a bulk sweetener. Food intake was measured at lunch offered 4 h after the breakfast meal, during the afternoon with access to abundant snacks, and finally at a supper buffet 9 h after the breakfast. Energy intake at lunch and during the snacking period was similar after ingesting the two sugars, while it was 15 % lower after ingesting d-tagatose than with sucrose at supper (P < 0·05). Gastrointestinal factors such as the osmotic effects of unabsorbed d-tagatose causing distension of the gut might have mediated the acute appetite-suppressing effect. The present paper also refers to data from a preceding study in which we observed an increased self-reported energy intake after ingestion of d-tagatose compared with sucrose which, in fact, suggests a relative hyperphagic effect of d-tagatose. However, self-reported food intake may be biased by selective under-reporting and this subsequent study with a more controlled assessment of food intake was therefore conducted. This present study did not support any hyperphagic effect of d-tagatose, but rather suggests that d-tagatose may contribute to a reduced energy intake.

scholarly journals Attenuated adenosine-sensitivity and decreased adenosine-receptor number in adipocyte plasma membranes in human obesity

1991 ◽  
Vol 279 (1) ◽  
pp. 17-22 ◽  
Author(s):  
J M Kaartinen ◽  
S P Hreniuk ◽  
L F Martin ◽  
S Ranta ◽  
K F LaNoue ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Cyclic Amp ◽  
Adenylate Cyclase ◽  
Adenosine Receptors ◽  
Plasma Membranes ◽  
Normal Weight ◽  
Fat Cells ◽  
Cyclic Amp Accumulation ◽  
Obese Subjects ◽  
Receptor Number

Fat-cells were isolated from patients of body-mass indices (BMIs) ranging from 17.9 to 83.9 kg/m2. Isoprenaline-stimulated cyclic AMP accumulation in cells prepared from obese subjects as compared with normal-weight subjects, was less sensitive to inhibition by the adenosine agonist N6-(phenylisopropyl)adenosine (PIA) (P = 0.047). The inhibition of 7 beta-desacetyl-7 beta-[gamma-(N-methylpiperazino) butyryl]-forskolin-stimulated adenylate cyclase by PIA in the presence of adenosine deaminase was also much attenuated in crude plasma membranes of adipocytes prepared from massively obese patients as compared with lean controls (P = 0.0143). This difference was probably not due to different cell size, because adenylate cyclase of crude plasma membranes of large adipocytes was actually more sensitive to PIA than was adenylate cyclase of membranes of smaller fat-cells co-isolated from the same individual. The stimulatory effect of PIA on glucose uptake in the presence of adenosine deaminase was depressed in adipocytes prepared from obese subjects and correlated with BMI at r = -0.626 (P = 0.007) at 100 nM-PIA. The adenosine receptors were studied by using the adenosine antagonist 1,3-[3H]dipropyl-8-cyclopentylxanthine. The binding was rapid and proportional to protein concentration. There was no difference in the affinities of receptors in membranes of obese and normal-weight subjects; Kd values of all patients averaged 3.3 nM. Bmax values were 54 and 130 fmol/mg of protein in membranes prepared from seven obese and five control patients respectively. The Bmax values calculated per mg of protein correlated with BMI at r = -0.539 (P = 0.047). The adenosine content of adipose tissue was higher in obese than in control subjects. These results demonstrate an attenuated response of cyclic AMP accumulation, adenylate cyclase and glucose uptake to adenosine in fat-cells prepared from obese subjects, and suggest that this change is at least partly due to changes in the amount of adenosine receptors, but not their affinity. The decreased receptor number could be due to higher adenosine content. A higher adenosine concentration in adipose tissue could explain why lipolysis is inhibited in situ in obesity, and the desensitization could explain the diminished response to adenosine analogues in isolated fat-cells.

scholarly journals G-proteins of fat-cells Role in hormonal regulation of intracellular inositol 1,4,5-trisphosphate

1986 ◽  
Vol 240 (1) ◽  
pp. 35-40 ◽  
Author(s):  
P J Rapiejko ◽  
J K Northup ◽  
T Evans ◽  
J E Brown ◽  
C C Malbon
Keyword(s):  
Adenylate Cyclase ◽  
G Proteins ◽  
Pertussis Toxin ◽  
Hormonal Regulation ◽  
Alpha Subunit ◽  
Fat Cells ◽  
Fat Cell ◽  
Alpha Subunits ◽  
Inositol 1,4,5 Trisphosphate ◽  
Rat Fat Cells

Pertussis toxin abolishes hormonal inhibition of adenylate cyclase, hormonal stimulation of inositol 1,4,5-trisphosphate accumulation in rat fat-cells, and catalyses the ADP-ribosylation of two peptides, of Mr 39,000 and 41,000 [Malbon, Rapiejko & Mangano (1985) J. Biol. Chem. 260, 2558-2564]. The 41,000-Mr peptide is the alpha-subunit of the G-protein, referred to as Gi, that is believed to mediate inhibitory control of adenylate cyclase by hormones. The nature of the 39,000-Mr substrate for pertussis toxin was investigated. The fat-cell 39,000-Mr peptide was compared structurally and immunologically with the alpha-subunits of two other G-proteins, Gt isolated from the rod outer segments of bovine retina and Go isolated from bovine brain. After radiolabelling in the presence of pertussis toxin and [32P]NAD+, the electrophoretic mobilities of the fat-cell 39,000-Mr peptide and the alpha-subunits of Go and Gt were nearly identical. Partial proteolysis of these ADP-ribosylated proteins generates peptide patterns that suggest the existence of a high degree of homology between the fat-cell 39,000-Mr peptide and the alpha-subunit of Go. Antisera raised against purified G-proteins and their subunits were used to probe immunoblots of purified Gt, Gi, Go, and fat-cell membrane proteins. Although recognizing the 36,000-Mr beta-subunit band of Gt, Gi, Go and a 36,000-Mr fat-cell peptide, antisera raised against Gt failed to recognize either the 39,000- or the 41,000-Mr peptides of fat-cells or the alpha-subunits of Go and Gi. Antisera raised against the alpha-subunit of Go, in contrast, recognized the 39,000-Mr peptide of rat fat-cells, but not the alpha-subunit of either Gi or Gt. These data establish the identity of Go, in addition to Gi, in fat-cell membranes and suggest the possibility that either Go or Gi alone, or both, may mediate hormonal regulation of adenylate cyclase and phospholipase C.

Fluctuations in basal plasma levels of pancreatic polypeptide in monkeys and humans

1985 ◽  
Vol 248 (6) ◽  
pp. R739-R747
Author(s):  
B. C. Hansen ◽  
K. L. Jen ◽  
S. B. Pek ◽  
R. A. Wolfe
Keyword(s):  
Pancreatic Polypeptide ◽  
Plasma Levels ◽  
Rhesus Monkeys ◽  
Human Subjects ◽  
Normal Weight ◽  
Central Venous ◽  
Basal Plasma ◽  
Obese Human ◽  
Spontaneous Fluctuations ◽  
Venous Plasma

We reported that significant rapid oscillations occur in basal plasma levels of insulin, glucagon, and glucose in rhesus monkeys and humans. We searched for evidence for similar spontaneous fluctuations also in plasma levels of pancreatic polypeptide (PP). Mean +/- SE basal plasma levels of PP were 236 +/- 15 pg/ml in 11 monkeys, 64 +/- 12 in nine normal-weight human subjects, and 74 +/- 10 in nine obese human subjects. 1) PP levels fluctuated with periods of 6–26 min. The fluctuations in PP were less regular than and did not temporally correlate with the fluctuations in plasma levels of insulin, glucagon, or glucose (usual periods 8–12 min). 2) In human subjects the concentration but not the periodicity of PP was related to obesity. 3) Comparisons of simultaneously determined levels of PP in portal and central venous plasma of monkeys suggested that PP may be extracted to varying degrees by the liver, even under basal well-controlled conditions, and that neither the size of the PP portal-central gradient nor the period and amplitude of fluctuations was associated with PP concentration. We conclude that plasma PP levels fluctuate with such a large amplitude that these fluctuations must be considered in the interpretation of experimental results based on limited numbers of samples.

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