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Query: UMLS:C0011849 (diabetes)
 277,896 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Isolated adipose tissue cells were prepared from subcutaneous samples obtained from nine morbidly obese subjects weighing from 187 to 306% of ideal body weight. The responsiveness of these adipocytes to a number of test substances was determined by measuring cellular cyclic AMP concentration at one-half hour and glycerol release at four hours. Theophylline (10(-3) M) and epinephrine (10(-5) M) stimulated lipolysis; theophylline stimulated an increase in cyclic AMP, while epinephrine failed to prompt a significant change in the nucleotide. Neither the alpha blocker, phentolamine (10(-5) M), nor the beta blocker, propranolol (3 X 10(-5) M), affected lipolysis or cyclic AMP; when these agents were incubated in combination with epinephrine, changes occurred indicative of the presence of both alpha and beta adrenergic receptor sites. Insulin significantly reduced both basal and stimulated lipolysis but failed to affect cyclic AMP. With minor exceptions, adipocytes from hyperobese subjects behaved similarly to cells from unselected donors; at the concentration used, there was no evidence of resistance to insulin.
Diabetes 1977 Jul
PMID:In-vitro observations on isolated adipose tissue cells from hyperobese subjects. 19 9

1. Rats were injected with a single dose of 35mg of streptozotocin/kg body wt. They exhibited a diabetes that was characterized by glycosuria, polyuria, polydipsia, hyperphagia, hyperglycaemia, increased concentrations of unesterified fatty acids, glycerol and triacylglycerols in the serum and an increased activity of glucose 6-phosphatase in the liver. 2. After 10 weeks the hepatic activities of the microsomal glycerol phosphate acyltransferase, phosphatidate phosphohydrolase, phosphatidate cytidylyltransferase, diacylglycerol acyltransferase, choline phosphotransferase, CDP-diacylglycerol--inositol phosphatidyltransferase and the soluble phosphatidate phosphohydrolase were measured. 3. The only significant changes were an increase in the activity of the soluble phosphatidate phosphohydrolase and a decrease in that of the CDP-diacylglycerol--inositol phosphatidyltransferase in the diabetic rats. 4. These results are discussed in relation to the control of glycerolipid synthesis.
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PMID:The effect of chronic diabetes, induced by streptozotocin, on the activities of some enzymes of glycerolipid synthesis in rat liver. 20 60

The in vitro relationship between fat-cell size, glycerol release, and peak concentration of cyclic AMP was investigated in human adipose tissue obtained from 25 obese nondiabetic patients before and after a 7-day fast and from 23 patients with untreated diabetes mellitus. In the obese nondiabetic patients there was a linear correlation between fat-cell size and cyclic AMP concentration, and fat-cell size and the rate of lipolysis. This was found both in nonfasting and fasting nondiabetic patients. However, in diabetes mellitus, there was only a relationship between cell size and cyclic AMP concentration. The alpha-adrenergic and beta-adrenergic activity in human adipose tissue was assessed by comparing the effect of isoprenaline and noradrenaline on the cyclic AMP concentration. The activity of both receptors was found to be increased in fasting obese patients and in diabetics. In both conditions the alpha-adrenergic response to catecholamines predominated in small fat cells, whereas in large ones the beta response predominated. The results suggest that during fasting and in diabetes mellitus there is a correlation between fat-cell size and the responsiveness of the adrenergic receptors. Thus, catecholamines may be involved in regulating the fat-cell volume. The view is expressed that the abnormal catecholamine-induced lipolysis is solely due to changes at the level of the adrenergic receptors during fasting, whereas in diabetes mellitus the sequentional activation of lipolysis is disturbed at deeper sites as well.
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PMID:Relationship between lipolysis, cyclic AMP, and fat-cell size in human adipose tissue during fasting and in diabetes mellitus. 21 83

1. Male rats were injected daily for 5 days with 0.15m-NaCl, corticotropin, cortisol or l-thyroxine and the rates of glycerolipid synthesis were measured in the livers after intraportal injection of [(14)C]palmitate and [(3)H]glycerol. 2. Injection of all three hormones decreased the rates of body-weight gain. 3. Cortisol treatment increased the weight of the liver relative to body weight. 4. Thyroxine treatment increased the relative rate of triacylglycerol synthesis from [(3)H]glycerol and decreased the relative accumulation of (3)H and (14)C in diacylglycerol. It did not significantly alter the accumulation of these isotopes in phosphatidate nor the activity of the soluble phosphatidate phosphohydrolase in the total liver. However, this activity increased by 1.5-fold when expressed relative to the soluble protein of the liver. The increased triacylglycerol synthesis appears to be related to a general increase in the turnover of fatty acids in the liver. 5. Treatment with cortisol and corticotropin increased the relative rate of triacylglycerol synthesis from [(3)H]glycerol, decreased the accumulation of (3)H in phosphatidate and increased the flux of both isotopes from phosphatidate to diacylglycerol. This appeared to be caused by the increased activity of the soluble phosphatidate phosphohydrolase that was observed in the livers of the cortisol-treated rats. 6. It is proposed that cortisol could be directly or indirectly involved in increasing the activity of hepatic phosphatidate phosphohydrolase in starvation, diabetes, laparotomy, subtotal hepatectomy, liver damage, ethanol feeding and in obesity. This enzyme adaptation could contribute to the potential of the liver to increase its synthesis and accumulation of triacylglycerols or to secrete very-low-density lipoproteins.
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PMID:The effects of cortisol, corticotropin and thyroxine on the synthesis of glycerolipids and on the phosphatidate phosphohydrolase activity in rat liver. 21 53

To gain information on the manner in which insulin suppresses lipolysis in man, isolated adipocytes, prepared from subcutaneous adipose tissue, were incubated with insulin (100 microunits/ml) alone and in combination with isoproterenol (10(-7) M or 10(-8) M). Cyclic AMP concentration was measured at 60 min; glycerol release, used as an index of lipolysis, was determined at 45 and 75 min. Insulin consistently reduced both basal and stimulated cyclic AMP and glycerol release: the degree of suppression of each was comparable. In subsequent experiments, the ability of insulin to suppress glycerol release stimulated by isoproterenol, theophylline, and dibutyryl cyclic AMP (dbcAMP), respectively, was compared. Insulin substantially reduced the raised levels of cyclic AMP and glycerol release prompted by isoproterenol and theophylline, but it had little effect on increases caused by dbcAMP. These findings support the view that reduction in cyclic AMP is an important component in the regulation of fat mobilization by insulin.
Diabetes 1979 Nov
PMID:Insulin inhibition of lipolysis of human adipocytes: the role of cyclic adenosine monophosphate. 22 42

Twelve hour metabolic rhythms have been performed on six maturity-onset diabetic subjects during successive periods of therapy with phenformin, metformin, and glibenclamide. Moderate control of blood glucose concentration was achieved with phenformin and metformin, the lowest concentrations being found with glibenclamide. Mean blood lactate concentration was grossly elevated during phenformin therapy, moderately elevated with metformin and normal during glibenclamide treatment. Similar patterns were found for the lactate/pyruvate ratio, alanine, glycerol and ketone bodies. Serum triglyceride concentrations were significantly higher during phenformin treatment than with the other two regimes. Serum insulin concentration was higher on glibenclamide than with either biguanide. Most of these effects of the biguanides could be accounted for by an inhibitory effect on hepatic gluconeogenesis. It is concluded that the use of biguanides as hypoglycaemic agents in diabetes is associated with the production of multiple metabolic abnormalities.
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PMID:Comparative effects of phenformin, metformin and glibenclamide on metabolic rhythms in maturity-onset diabetics. 40 5

We report unusually high concentrations of free fatty acids and glycerol in sera of patients with adult-onset diabetes, and the accompanying alterations in creatine kinase isoenzyme MM patterns associated with such patients. The serum samples with increased free fatty acids also showed increased electrophoretic movement of the MM isoenzyme on cellulose acetate membranes. Fatty acid concentrations found in such samples averaged 9.88 +/- 5.65 (SD) meq/L and the average glycerol concentration was 153 +/- 115 (SD) mg/L. The serum glycerol concentrations correlated with those of the free fatty acids (r = 0.886, slope = 0.309, intercept = 4.76).
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PMID:Increased concentrations of free fatty acids and glycerol and altered creatine kinase MM isoenzyme patterns in certain diabetic patients. 46 58

This review concerns the present state of accomplishments in the study of SEM of human and experimental renal disease. Critical techniques of specimen preparation reviewed include perfusion fixation, razor tissue sectioning, alcohol cryofracture, microtome sectioning of paraffin or styrene embedded tissue, ultraplaning with glass knives of hard carbowax embedded tissues and glomerular isolation. Gold-palladium coating and heavy metal impregnation with osmium, uranium, and silver are discussed. A compendium of SEM observations of human glomerular, vascular and tubular disease is presented. Techniques for SEM of experimental renal disease are reviewed. These include latex vascular injection, freeze drying, x-ray microanalysis and use of backscattered electron imaging. Experimental models previously investigated by SEM are puromycin aminonucleoside nephrosis, daunomycin nephrosis, and N,N1-Diacetylbenzedine glomerulopathy, nephrotoxic serum nephritis, and protamine perfusion glomerulopathy. Reviewed are acute tubular necrosis caused either by angiotensin, hypotension, norepinephrine, glycerol, mercury, and unilateral renal artery occlusion, also potassium depletion nephropathy, alloxan diabetes and diphenylamine-induced polycystic disease.
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PMID:SEM of human and experimental renal disease. 52 33

A 70-yr-old mildly diabetic white male was discovered to have an elevated level of serum free glycerol in the range of 75 mg/dl and to excrete about 13 g of free glycerol in the urine per 24 h. During a 24-h fast the urine glycerol loss increased to 21.5 g per 24 h. Studies carried out in vitro using leukocytes prepared from the patient's blood which were incubated with [14C]glycerol demonstrated an almost complete absence of glycerol oxidation to 14CO2 and of glycerol phosphorylation, in contrast to control studies with leukocytes collected from normal subjects. Homogenates of the patient's leukocytes contained negligible activity of ATP:glycerol phosphotransferase (glycerokinase EC 2.7.1.30) as measured by a direct spectrophotometric method. Marked hyperglycerolemia has thus far been detected in one brother and in one son of the daughter of this patient. This evidence suggests an x-linked recessive inheritance pattern of the trait. There is a high prevalence of diabetes mellitus in this family.
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PMID:Familial hyperglycerolemia. 61 10

Dichloroacetate is known to reduce plasma glucose and triglycerides in diabetic and starved animals and to lower plasma lactate under various experimental conditions. To investigate its metabolic effects in man, we administered oral doses (3 to 4 g) of dichloroacetate as the sodium salt to patients with diabetes mellitus or hyperlipoproteinemia or both for six to seven days. Dichloroacetate significantly reduced fasting hyperglycemia an average of 24 per cent (P less than 0.01) from base line and produced marked, concomitant falls in plasma lactate (73 per cent; P less than 0.05 to less than 0.01) and alanine (82 per cent; P less than 0.01 to less than 0.001). In addition, it significantly decreased plasma cholesterol (22 per cent; P less than 0.01 to less than 0.001) and triglyceride (61 per cent; P less than 0.01) levels while increasing (71 per cent; P less than 0.01) plasma ketone-body concentrations. Plasma insulin, free fatty acid and glycerol levels were not affected. Serum uric acid rose, whereas excretion and renal clearance fell. Some patients experienced mild sedation, but no other laboratory or clinical evidence of adverse effects was noted during or immediately after the treatment phase.
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PMID:Metabolic effects of dichloroacetate in patients with diabetes mellitus and hyperlipoproteinemia. 62 8


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