Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0028754 (obesity)
 124,988 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Endogenous factors cross-reacting with antidigoxin antibodies have been found in several tissues and body fluids of animals and humans, using commercially available digoxin radioimmunoassay or enzyme immunoassay methods. The chemical characteristics of these endogenous factors are, at present, unknown, although it has been suggested that they could be substances with low molecular weight. Experimental studies and theoretical considerations indicate that endogenous digitalis-like factors (DDLFs), in addition to the ability to react with antibodies, might also bind to the specific cellular receptor of the cardiac glycosides and thus inhibit the membrane Na+/K(+)-ATPase (sodium pump). Therefore, EDLF can be an endogenous modulator of the membrane sodium-potassium pump and several authors have suggested that EDLF could play a role in the regulation of fluids and electrolytes, muscular tone of myocardial and also in the pathogenesis of arterial hypertension. In this review, the authors discuss the hypothesis that, in metabolic diseases such as diabetes mellitus, obesity and acromegaly, the sodium retention and volume expansion, possibly due to exaggerated sodium intake, and/or exogenously induced peripheral hyperinsulinemia and high levels of growth hormone, could trigger a sustained release of EDLF, which in turn increases the blood pressure.
 ...
PMID:Is the endogenous digitalis-like factor the link between hypertension and metabolic disorders as diabetes mellitus, obesity and acromegaly? 222 23

Specific ouabain binding, active rubidium transport and sodium-lithium countertransport were studied in erythrocytes of 55 normal weight (BMI less than 27), 10 overweight (27 less than or equal to BMI less than 32) and 27 obese (BMI greater than or equal to 32) Finnish subjects after re-examination of the methods. Intra-assay variation coefficients for these three determinations were 6 percent, 6 percent and 12 percent, respectively. When samples from the same subjects were analyzed again after one month interval no significant differences were obtained between the measurements. However, storing of the cells at +4 degrees C increased Na-K-ATPase mediated rubidium transport about 1.5-fold within one day which may partly account for the discrepancies between the previously reported results. Specific ouabain binding of the overweight group appeared to be slightly lower (13.4 percent, P less than 0.05) whereas that of the obese subjects was slightly higher (8.7 percent, P less than 0.05) in comparison with normal weight subjects. Also in active rubidium transport and sodium-lithium countertransport the values of the obese subjects were significantly higher (P less than 0.01, and P less than 0.05, respectively) than those of the normal weight subjects. Furthermore, there existed a significant correlation between active rubidium transport and body mass index (r = 0.34; P less than 0.001) and also between active rubidium transport and specific ouabain binding (r = 0.67; P less than 0.001). In spite of these differences between obese and normal weight subjects there existed considerable overlapping between the groups, and these changes cannot be used as diagnostic tools in screening persons metabolically susceptible to obesity.
 ...
PMID:Red-cell sodium-potassium pump and sodium-lithium countertransport in human obesity. Re-evaluation of the methods and association in a Finnish population. 241 3

Leucocyte ouabain-sensitive 22Na+ efflux was studied in 35 normal and 12 obese subjects. This efflux rate constant was raised in the obese (2.72 +/- SEM 0.13 vs 2.31 +/- 0.08 h-1, P less than 0.006), indicating a higher activity of the sodium pump in vivo, There was a significant correlation between this efflux rate constant and fasting insulin level in both the whole population and in the normals alone (rs = 0.36, P less than 0.007, and rs = 0.40, P less than 0.009 respectively). A hyperinsulinaemic-euglycaemic clamp was performed on seven normal volunteers. After 2 h, there was a significant stimulation of the leucocyte efflux rate constant (from 2.86 +/- 0.17 to 3.33 +/- 0.18 h-1, P less than 0.01). In-vitro incubation of leucocytes with insulin produced a maximal stimulation of the Na+-K+-ATPase activity of about 35% at 2 h with half-maximal stimulation achieved at 46 mU/l. Insulin (100 mU/l) also stimulated the leucocyte ouabain-sensitive 22Na+ efflux rate constant in vitro by about 11% with or without 1 h of preincubation with the insulin. These findings may explain the hypokalaemic and sodium retaining effects of insulin in man; they may also partially explain the raised Na+ efflux rate constants in obesity.
 ...
PMID:The leucocyte sodium pump in healthy and obese subjects: the association of insulin with its activity. 244 7

The number and activity of erythrocyte ATPase-dependent sodium-potassium pump units were increased in obese subjects (p = 0.02). No link was observed between the number or activity of the pump units and hypertension. The ouabain-insensitive rubidium (i.e. potassium) transport was not associated with relative body weight or blood pressure status. Sodium-lithium countertransport correlated significantly with obesity but not with blood pressure status. In the hypertensive patients, before or after therapy with verapamil, hydrochlorothiazide, pindolol or atenolol there were no significant differences in cation transport. We propose that the correlation between obesity and essential hypertension cannot be explained by these two cation transport systems.
 ...
PMID:Erythrocyte cation transport in obesity, hypertension, and during antihypertensive drug therapy. 257 70

A study was made of the erythrocytic membranes in patients with stage II-III metabolic and alimentary obesity. The red blood cells may serve as model of the membranes of other cells of the internal organs, that is why their changes are likely to mirror the total impairment of the function of the cell membranes in the illness under consideration. The patients' red blood cells were characterized by high permeability, increased ATPase activity, catalase activation, reduction of the content of the thiol groups, and by the displacement of the thiol-disulfide balance towards oxidized forms. A correlation was discovered between the elevation of red blood cell permeability and red blood cell K+, Na+-ATPase activation. The changes in the thiol-disulfide balance brought about inconclusive shifts in the magnitude of permeability, in the activity of ATPase isoenzymes, and in the content of cholesterol fractions in red blood cells of patients with metabolic and alimentary obesity. The changes thus discovered are of paramount importance for understanding the pathogenesis of metabolic abnormalities associated with obesity and for rational treatment of this patients' group.
 ...
PMID:[New data on characteristics of the chemism of erythrocytes in patients with metabolic-alimentary obesity]. 280 Apr 51

In a search for the role of long-term hypocaloric feeding on the expression of the erythrocyte Na pump in obesity, we examined three groups of subjects. Group 1 consisted of 10 obese subjects who had been under treatment for a long period of time with a very-low-calorie diet (500 kcal/d) while group 2 consisted of 10 age-, sex-, and body mass index-matched obese subjects on their usual diet; in the third group, 12 normal-weight subjects on a free diet served as controls. There was no difference between the groups in the number of erythrocyte binding sites per cell. On the contrary, the Na-K-ATPase activity was significantly lower in the obese group 1 (0.35 +/- 0.09 mumol Pi x mg protein-1 x h-1) compared to that observed in the obese group 2 (0.42 +/- 0.07, P less than .05) and in control subjects (0.45 +/- 0.06, P less than .05). Sex, duration of hypocaloric feeding, and the amount of weight loss before the study in the obese group 1 seemed not to be related to the Na pump parameters. We conclude that long-term severe hypocaloric feeding may be a factor in altered erythrocyte Na-K-ATPase in obese individuals.
 ...
PMID:Erythrocyte Na-K-ATPase membrane activity in obese patients fed over a long-term period with a very-low-calorie diet. 282 67

1. Intracellular Na+ concentration [Na+]i and Na+ extrusion catalysed by sodium potassium-activated adenosine triphosphatase (Na+, K+-pump) were evaluated in erythrocytes from 21 obese children and 20 normal weight- and age-matched controls. 2. Obese children showed a significantly decreased Vmax. for Na+, K+-pump-mediated Na+ efflux (5638 +/- 338 vs 7597 +/- 335 mumol h-1 litre-1 of cells mean +/- SEM, P = 0.01), while [Na+]i (9.3 +/- 0.3 vs 9.1 +/- 0.5 mmol/litre of cells, mean +/- SEM, NS) and Na+ efflux in fresh cells (2380 +/- 153 vs 2533 +/- 180 mumol h-1 litre-1 of cells, mean +/- SEM, NS) were similar in both groups. 3. Mean diastolic blood pressure was significantly higher in obese children than in controls, although both groups were normotensive (73.8 +/- 1.3 vs 66.2 +/- 1.9 mmHg, mean +/- SEM, P = 0.009). 4. Abnormal Na+, K+-pump activity is present in individuals with idiopathic obesity. 5. The possible link between obesity and blood pressure regulation may be mediated through modifications in Na+,K+-pump activity.
 ...
PMID:Abnormalities of sodium transport by sodium, potassium-activated adenosine triphosphatase in erythrocytes from obese children. 282 39

A number of previous investigations in obese and normal-weight adults suggested a link between (usually) lower than normal erythrocyte Na+-K+ ATPase activity and obesity, although more recent studies have disputed this link. Developmental patterns of ATPase activity in children have not been studied. Infants of diabetic mothers show an increased incidence of macrosomia and such infants are at risk for later development of obesity. These children provide an ideal group to study the link (if any) between this enzyme and obesity, as well as changes in the level of the enzyme which may occur with age and/or the onset of obesity. The Na+-K+ ATPase levels in erythrocytes from 87 normal children and 27 infants of diabetic mothers were therefore studied by an ouabain-binding method. The study populations contained representatives of three ethnic groups (black, Caucasian and Hispanic) and individuals of normal body weight, as well as overweight and obese individuals. The ATPase activities were not correlated with body weight, sex, or age, nor was umbilical cord red cell ATPase correlated with birthweight. Several children who are being followed have shown considerable variation in percentage ideal body weight (IBW); however their ATPase levels have remained unchanged. There were, however, significant differences among the ethnic groups, with Caucasians having the highest values (0.443 +/- 0.012 pmol ouabain bound/10(9) cells). These data demonstrate the importance of matching study groups by race when investigating factors affecting this enzyme. The differences among the ethnic groups suggest a genetic component in the determination of the activity of this enzyme. This link was further investigated in 14 families and revealed considerable heterogeneity within a given ethnic group, with family members generally having similar enzyme activities, thus supporting a genetic basis for the different enzyme levels. Thus erythrocyte Na+-K+ ATPase in childhood is primarily regulated by genetic factors which are generally independent of body weight.
 ...
PMID:Erythrocyte Na+-K+ ATPase activity in childhood: regulation by genetic factors independent of body weight. 283 Nov 62

A number of erythrocyte Na-K ATPase units were measured in 22 patients with hyperthyroid Graves' disease, 3 with primary hypothyroidism, 3 with simple obesity, 13 with chronic renal failure on hemodialysis, and 20 normal controls, using ouabain binding assay as described by DeLuise et al. The number of Na-K ATPase units, derived by maximal binding of 3H-ouabain, was decreased in patients with simple obesity (Mean +/- SD, 0.26 +/- 0.07 pmol/10(9) RBC), as compared with that in normal controls (0.39 +/- 0.10), and a significant negative correlation between the number of the binding sites and the ratio of the measured body weight to the optimal body weight calculated by the modified Broca's method was observed in normal controls and patients with obesity (r = -0.51, p less than 0.05). The results agreed closely with that reported by DeLuise et al and provided validation of our estimates of the erythrocyte Na-K pump units. The maximal 3H-ouabain binding was significantly diminished in patients with hyperthyroid Graves' disease (0.28 +/- 0.07) when compared with that in normal controls, while the bindings were significantly elevated in patients with hypothyroidism (0.91 +/- 0.26). These results were in disagreement with those previously reported by animal studies where Na-K ATPase was found to be stimulated by thyroid hormones. It might be possible to partly explain this discrepancy by the degradation of Na-K ATPase in erythrocytes in addition to the apparent differences between erythrocytes and the other tissues and by the length of time that the tissue was exposed to the action of the hormones. Therefore, erythrocyte from normal controls and patients with hyperthyroid Graves' disease were divided into low and high density portions by a discontinuous 'percoll' density gradient centrifugation, and the bindings of the erythrocytes in two portions were separately measured. The bindings of erythrocyte in the higher density portion, representing relatively old-aged erythrocyte, were diminished to 92 +/- 19% of the bindings of the original whole erythrocytes in normal controls. An even more marked reduction of the maximal bindings of 3H-ouabain in old-aged erythrocytes was observed in patients with hyperthyroid Graves' disease (72 +/- 26%). Moreover, this % reduction based on aging related significantly to serum T4 concentrations in those patients (r = 0.85, p less than 0.05). These findings suggest that the number of erythrocyte Na-K ATPase units may reflect the overall peripheral metabolic state, regulated by thyroid hormone-dependent thermogenesis.(ABSTRACT TRUNCATED AT 400 WORDS)
 ...
PMID:[Clinical studies on assay for Na-K ATPase in human blood cells. I. Erythrocyte Na-K ATPase assay in patients with thyroid dysfunction and in those with chronic renal failure]. 284 3

The number of Na-K pump units, the Na-K-ATPase activity, the K transport turnover rate per pump unit and the intracellular Na and K concentrations were measured in the erythrocytes of 56 obese patients and 20 normal subjects. No differences were found between the two groups. In obese patients, we failed to observe any influence of dietary habits, age of onset, or family history of obesity on the Na pump status. On the other hand, we found that the number of pump units was not a close reflection of the membrane cation transport and in some patients with an abnormally high number of pump units, an inappropriately low Na-K-ATPase activity was observed. We also identified two small groups of obese patients with, respectively, abnormally high or low K transport turnover rate per pump unit. Our study seems to support the hypothesis that abnormalities in the erythrocyte Na-K pump system are not usual in the obese population but are probably present only in a limited number of selected patients.
 ...
PMID:Heterogeneity of the erythrocyte Na-K pump status in human obesity. 299 83


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>