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

Supplementation of rat lymphocyte cultures with plasma from alloxan-diabetic rats produced a dose-dependent suppression of mitogen-induced blastogenic responses. Viability measurements indicated that this inhibition was not due to a direct cytotoxic effect of alloxan-diabetic plasma on rat mononuclear leukocytes in vitro. This inhibition was not explained by hyperglycemia alone and was observed when blastogenesis was induced in vitro by phytohemagglutinin (PHA), concanavalin A (con A), or allogeneic cells. Peripheral blood lymphocytes from alloxan-diabetic rats appeared to be more sensitive than normal cells to the inhibitory effect of diabetic plasma. Heating at 56 degrees for 60 minutes produced only a partial loss of the inhibition by diabetic plasma. Alloxan-diabetic rat plasma promoted an increased accumulation of adenosine 3',5'-monophosphate (cyclic AMP) in mononuclear leukocytes. Insulin (1 and 100 muU./ml.) in vitro enhanced PHA-induced blastogenesis but failed to reverse the inhibition caused by diabetic plasma. Ultrafiltration through a cellulose dialysis membrane with an exclusion size of 12,000 molecular weight did not remove the inhibitory factor(s). These results indicate that a depressed cellular immune response is produced during an insulin-deficient diabetic state. The suppressed in-vitro blastogenic response of lymphocytes from alloxan-diabetic rats appears to involve some circulating inhibitory factor(s) in diabetic plasma. This inhibition may be explained, in part, by the ability of diabetic plasma to elevate cyclic AMP in mononuclear leukocytes.
Diabetes 1976 Jul
PMID:Inhibition of lymphocyte blastogenesis by factor(s) in alloxan-diabetic rat plasma. 17 6

1. Epinephrine-induced increase in rat liver cyclic AMP in vivo was potentiated when the circulating insulin was suppressed by injection of anti-insulin serum or by induction of diabetes. Consequently, phosphorylase was activated, glycogen synthetase was inactivated and glycogen accumulation induced by glucose load was prevented by epinephrine in the insulin-deficient rats to a much larger extent than in normal rats. 2. Insulin lack was effective in potentiating epinephrine-induced increase in liver and muscule cyclic AMP even after the treatment of rats with theophylline; the potentiation could not be solely accounted for by the inhibition of cyclic AMP phosphodiesterase. Thus, it is likely that insulin lack enhaces epinephrine activation of adenylate cyclase. 3. Unlike epinephrine, glucagon increased liver cyclic AMP to essentially the same extent whether the rat was treated with anti-insulin serum or not. 4. Based on the difference in dose-response curves between normal and insulin-deficient rats, a possibility is discussed that there are two adenylate cylase in the liver with higher and lower affinities for epinephrine and that circulating insulin blocks the high affinity enzyme selectively.
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PMID:Attenuation of epinephrine-induced increase in liver cyclic AMP by endogeneous insulin in vivo. 18 27

The sensitivity of alpha- and beta-adrenergic receptors, and the antilipolytic actions of prostaglandin E1 or insulin on adipose tissue of obese diabetic and non-diabetic subjects have been studied. Accumulation of cyclic AMP in adipose tissue and release of glycerol in response to several catecholamines (adrenaline, noradrenaline and isoprenaline) in the presence or absence of an alpha-adrenergic blocker (phentolamine) have been used to assess catecholamine receptor sensitivity. No differences in beta-receptor activity were observed between diabetics and non-diabetics, either on glycerol release or accumulation of cyclic AMP; alpha-receptor activity was also similar, except for significantly less accumulation of cyclic AMP in diabetic tissue incubated with noradrenaline and phentolamine (p less than 0.01). The antilipolytic action of prostaglandin E1 (at concentrations of 30 fM to 30 pM) on lipolysis (stimulated submaximally with isoprenaline, 10(-7) M) was similar in diabetic and control groups. The antilipolytic action of insulin (from 10(-10) to 10(-6) M) on lipolysis was also similar between the groups. It is concluded that neither disorders of the catecholamine receptor nor of the antiliolytic actions of prostaglandin E1 or insulin are responsible for the abnormalities of fatty acid metabolism in adult diabetes.
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PMID:Catecholamine receptor sensitivity and the regulation of lipolysis in adult diabetes. 18 98

The results of clinical and biochemical investigations on a girl with all obligatory signs of Mauriac syndrome already in infancy were compared with the different hypotheses suggested in order to explain the pathogenesis of this disease. One possible explanation for the origin of MS might be a decreased sensitivity of adenylate-cyclase to glucagon or adrenalin. Hypersensitivity to insulin, resulting in a decreased production of cyclic AMP and activation of glycogen synthetase could be excluded by measuring the urine excretion of cAMP with and without insulin. Furthermore no signs of dyspituarism were detectable on our case and the hypothesis of MS being a combination of primary glycogenosis and diabetes mellitus could also be refuted. Liver enzyme activities were normal.
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PMID:[Pathogenetic investigations on a case of mauriac syndrome (author's transl)]. 18 11

Normal male rats were made chronically diabetic by injection of alloxan or acutely diabetic by injection of anti-insulin serum. The concentration of cyclic AMP in epididymal adipose tissue was increased approximately 2 1/2-fold 24 h after alloxan administration and up to 7-fold 72 h post-alloxan. Treatment of alloxan-diabetic rats with insulin for 4 h completely suppressed lipolysis but only partially suppressed cyclic AMP levels; 6 h following insulin treatment cyclic AMP levels were normal. When segments of the epididymal fat bodies were incubated in vitro the high cyclic AMP levels were not maintained but instead decreased spontaneously. Addition of insulin to the incubation media decreased lipolysis in tissues of diabetic rats to levels measured in tissues of normal rats and accelerated the decline in cyclic AMP levels but did not return cyclic AMP levels to normal. Rats rendered acutely insulin deficient by injection of anti-insulin serum showed increased plasma glucose and free fatty acid levels and increased adipose tissue free fatty acid, and cyclic AMP levels 30 min following injection of the antiserum. Plasma glucagon levels increased but not until 2 h following anti-insulin serum, thereby excluding the possibility that an increment in plasma glucagon is the primary stimulus for the acceleration of lipolysis in diabetes. These data are consistent with the view that control of adipose tissue cyclic AMP levels in situ is an important physiologic action of insulin.
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PMID:Adenosine 3',5'cyclic monophosphate in adipose tissue of diabetic rats. 18 24

Subcutaneous adipose tissue was obtained from 9 patients with untreated diabetes mellitus and from 13 obese nondiabetics. After incubation with isoprenaline or noradrenaline, glycerol release and tissue cyclic AMP (cAMP) were determined. Basal glycerol release was twice as rapid from the diabetic adipose tissue. With isoprenaline, the cAMP concentration and the glycerol production was significantly higher in the diabetic adipose tissue. Noradrenaline did not increase glycerol production or cAMP concentration in the diabetic adipose tissue. Subcutaneous adipose tissue was also removed from the diabetics after antidiabetic treatment. Basal lipolysis was significantly reduced and noradrenaline significantly increased both glycerol release and cAMP production. With isoprenaline, cAMP production and glycerol release were significantly less after antidiabetic treatment than in the untreated state. The data provide evidence for increased alpha- as well as beta-adrenergic receptor sensitivity in human subcutaneous adipose tissue of untreated diabetic patients.
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PMID:Abnormalities in the adrenergic control and the rate of lipolysis in isolated human subcutaneous adipose tissue in diabetes mellitus. 18 19

Numerous general metabolic systems are disturbed in association with psoriasis: the frequency of diabetes mellitus and of hyperuricaemia, lipid disturbances and a decrease in folates as a result of their excessive consumption by the skin. Cutaneous metabolism is also altered. Numerous compounds are formed in excess from glucose: amino acids, fatty acids and sterols, lactic acid--the formation of which persists in the corneal layer, ribose and ribulose--synthesised as a result of glucose-6-phosphate-dehydrogenase hyperactivity (role of the increased catabolism of dehydro-epi-androsterone) and uronic acids. The accumulation of glycogen is probably due to excessive synthesis and impaired breakdown. These abnormalities may exist to a lesser extent in healthy skin. In the corneal layer there are lipid vacuoles visible under the electron microscope. Lipogenesis is increased. The same may apply to lipolysis (blood NEFA are increased). Esterification of cholesterol is decreased. The utilisation of ATP by cell membranes is probably diminished (low ATP ase activity). The absence of formation of keratohyaline is due to persistence of the repression which normally prevents it in the mucus body. Renewal of collagen appears increased. The synthesis of DNA is increased in the lesions and neighbouring areas. It is possible that these various abnormalities are dependent upon modifications in the regulator systems of cyclic AMP and GMP, variations in which are however discussed.
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PMID:[The biochemistry of psoriasis]. 18 76

The effects of glucagon on tissue and plasma cyclic AMP levels have been investigated in rabbits anesthetized with urethane. Glucagon (2 nmole/kg.) caused at least a twofold increase in hepatic cyclic AMP, which reached a peak within two minutes and declined to basal values after 40 minutes. Plasma cyclic AMP also increased at least twofold, reaching a peak at 10 minutes and declining to basal values after 60 minutes. Glucagon (20 nmole/kg.) stimulated hepatic and plasma cyclic AMP in a manner indistinguishable from that observed at the lower dose. Hepatectomy abolished the plasma cyclic AMP responses to glucagon, and no significant stimulation of cyclic AMP concentration was noted in the heart, adipose tissue, small bowel, or kidney. Cyclic AMP hydrolysis was estimated in blood taken before and after administration of glucagon. Glucagon (2 nmole/kg.) increased cyclic AMP hydrolysis slightly, but this was explained by the raised cyclic AMP levels. By contrast, cyclic AMP hydrolysis increased two-to-threefold in blood taken 20 and 40 minutes after glucagon (20 nmole/kg.). The higher dose of glucagon also stimulated cyclic AMP hydrolysis in crude liver homogenate, which could not be explained by increases in cyclic AMP concentration. The increase in cyclic AMP hydrolysis observed in blood and liver may partly explain the failure to show additional stimulation of hepatic and plasma cyclic AMP levels with the higher dose of glucagon. Despite the changes in cyclic AMP hydrolysis, a highly significant correlation was observed in individual rabbits between the hepatic and plasma cyclic AMP responses to glucagon (2 and 20 nmole/kg.), when these were calculated as incremental areas above mean basal levels. It is suggested that measurement of plasma cyclic AMP levels after stimulation by glucagon may be an accurate index of the hepatic cyclic AMP response to glucagon in vivo.
Diabetes 1977 Feb
PMID:The cyclic AMP response to glucagon. Comparison of tissue and plasma cyclic AMP levels in the rabbit. 19 72

The metabolic response to intravenous glucagon was studied in insulin requiring diabetes before, 1 week and 1 month after treatment with insulin. The rise in plasma 3-hydroxybutyrate following glucagon in the untreated state was converted to a fall after 1 month on insulin. It is suggested that this response could provide a measure of the biological effectiveness of circulating insulin. There was no change in plasma cyclic AMP response to glucagon after treatment with insulin.
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PMID:The effect of insulin treatment on the metabolic response to glucagon in diabetes. 19 10

In perfused livers of fed rats, chlorpropamide inhibits glucagon-stimulated glucose production by augmenting the action of insulin. This effect is associated with a decrease in cyclic AMP accumulation in liver and perfusate. Alterations in glucose production appear to correlate more closely with changes in the amount of cyclic AMP in the perfusate than with changes in intrahepatic concentration of nucleotide. Potenitation by chlorpropamide of the hepatic action of insulin does not require administration of the drug prior to perfusion. Further, it is demonstrable at concentrations of insulin and glucagon (10(-11M) that approximate the normal plasma levels of these hormones.
Diabetes 1977 May
PMID:Potentiation of the hepatic action of insulin by chlorpropamide. 19 17


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