Development Of Alloxan Diabetes Research Articles

Изучение окислительных процессов при развитии сахарного диабета у экспериментальных животных

The gradual destruction of β-cells of the pancreas leads to insulin deficiency, diabetes mellitus develops, which is manifested by severe disorders of carbohydrate-energy metabolism, chronic hyperglycemia is accompanied by an imbalance of all functional systems of the body. Therefore, it is possible to study metabolic processes that can lead to the gradual destruction of β-cells. The aim of this study was to investigate the processes of lipid peroxidation in the total homogenate of the pancreas and liver of alloxaninduced rats, the amount of nitric oxide, and the state of the thiolisulfide system. As it is stated by the results of the study, the oxidative processes in the total homogenates of the pancreas and liver of model rats showed accumulation of lipid peroxidation products (hydroxides, malondialdehyde, Schiff bases). In alloxan-induced diabetes mellitus, a decrease in the SH content, an increase in the content of oxidized SS-groups of thiols and NO were found in the pancreas. According to the results of our research, it can be concluded that with the development of alloxan diabetes, an increase in the concentration of active compounds in the pancreas and liver is observed, which leads to disruption of the normal functioning of metabolic processes.

Molecular and biochemical studies of succinate dehydrogenase in rat liver under conditions of alloxan diabetes

Experimental alloxan diabetes in rats causes an increase in the activity of liver succinate dehydrogenase (SDH) without changes in its isozyme composition. The observed increase in the catalytic activity of SDH clearly correlates with the intensification of transcription of the genes encoding catalytic dimer of SDH. Analysis of the methyl status of the promoters of the genes, encoding the catalytic dimer of SDH in rats under normal and experimental conditions did not reveal any dependence on the level of their expression. The obtained results of bisulfite sequencing indicate a passive role of the epigenetic mechanism of regulation of SDH gene expression in the development of alloxan diabetes. The transcription factor CREB, responsible for of gluconeogenesis in diabetes, may play an important role in the control of the transcriptional activity of the sdha and sdhb genes.

The antidepressant effects of α-lipoic acid and reamberin in murine alloxan diabetes

The development of alloxan diabetes in mice is followed by a longer duration of despair behavior, homologous depression in man and a concomitant decrease in the activity of animals in the open field. The 2-week course of α-lipoic acid (α-LA) and reamberin in the doses equivalent to the human therapeutic range exerts an antidepressant activity, as appeared by a reduction in despair behavior and activation of sick mice in the open field. The antidepressant effect of 2-week use of α-LA and reamberin is associated with diminished hyperglycemia. Unlike α-LA, reamberin lowers the blood content of glucose in mice with alloxan diabetes, reduces their mortality, and corrects behavioral disorders in the open field even when relatively low doses are singly administered.

Insulin potentiating effect on development of alloxan diabetes and its prevention by the Ca-channel blocker nicardipine.

Insulin potentiating effect on development of alloxan diabetes and its prevention by the Ca-channel blocker nicardipine.

Comparative toxicity of alloxan, N-alkylalloxans and ninhydrin to isolated pancreatic islets in vitro

The in vitro toxicity of the diabetogenic agent alloxan as documented by the induction of beta cell necrosis was studied in isolated ob/ob mouse pancreatic islets. The effect of alloxan has been compared with that of a number of N-alkyl alloxan derivatives and with that of the structurally related compound, ninhydrin. Alloxan and its derivatives were selectively toxic to pancreatic beta cells, with other endocrine cells and exocrine parenchymal cells being well preserved, even at high concentration. In contrast, ninhydrin was selectively toxic to pancreatic beta cells only at comparatively low concentration, destroying all islet cell types at high concentrations. The ultrastructural changes induced by all the test compounds in pancreatic beta cells in vitro were very similar to those observed during the development of alloxan diabetes in vivo. The relative toxicity of the various compounds to pancreatic beta cells in vitro was not, however, related to their ability to cause diabetes in vivo. Indeed, the non-diabetogenic substances ninhydrin, N-butylalloxan and N-isobutylalloxan were very much more toxic to isolated islets than the diabetogenic compounds alloxan and N-methylalloxan. These results suggest that the differences in diabetogenicity among alloxan derivatives are not due to intrinsic differences in the susceptibility of the pancreatic beta cells to their toxicity, but may reflect differences in distribution or metabolism. High concentrations of glucose protected islets against the harmful effects of alloxan and its derivatives, but not those of ninhydrin. Low levels of glucose, and non-carbohydrate nutrients, afforded little protection, indicating that the effect of glucose is not due to the production of reducing equivalents within the cell, 3-O-Methylglucose, which protects against alloan diabetes in vivo, did not protect against alloxan toxicity in vitro. Since 3-O-methylglucose is known to prevent uptake of alloxan by pancreatic beta cells, it appears that uptake of alloxan by the cell is not a prerequisite for the induction of beta cell necrosis.

Antioxidant probucol prevents development of alloxan diabetes and hypoactivity of antioxidant enzymes in rat tissues

Antioxidant probucol prevents development of alloxan diabetes and hypoactivity of antioxidant enzymes in rat tissues

Changes in some parameters of lipid metabolism in erythrocyte membranes during development of alloxan diabetes

Changes in some parameters of lipid metabolism in erythrocyte membranes during development of alloxan diabetes

Effects of D-mannoheptulose on blood glucose and alloxan sensitivity in mice.

D-mannoheptulose (MH) administration induced a decreased serum insulin concentration in fed and starved mice, and a transient hyperglycaemia in fed mice, but not in starved ones. The liver glycogen concentration was decreased in starved controls and in fed mice treated with MH. Differences in the capacity for rapid hepatic glycogenolysis may have contributed to the different blood glucose responses in fed and starved mice. The hyperglycaemia in fed mice was unaffected by pre-treatment with L-leucine, or p-hydroxymercuribenzoate (PMB), but was abolished by pre-treatment with tolbutamide, and by post-treatment with insulin. Treatment of fed mice with MH before alloxan caused a marked "initial" hyperglycaemia but no second hyperglycaemia, and thus no development of alloxan diabetes. In starved mice injected with MH before alloxan there was an inhibition of the initial hyperglycaemia, but occurrence of a "second" hyperglycaemia, suggesting an absence of protection against the development of alloxan diabetes. The data show that alloxan diabetes may develop in the absence of an "initial" hyperglycaemia and a triphase blood glucose response. The hyperglycaemic action of MH in fed mice is believed to underlie the protection against alloxan toxicity.

Stereological study of B-cell mitochondria in alloxan-treated mice.

Using stereological techniques, including semi-automatic image analysis, the B-cell mitochondria were studied in the pancreatic islets from one group of control mice and two groups of mice killed 10 min and 60 min, respectively, after alloxan administration. Ten min following alloxan the mitochondrial volume and envelope surface densities, the mean mitochondrial volume and surface area, and the area of mitochondrial profiles were significantly increased, whereas the mitochondrial numerical density was not significantly altered. At the 60 min observation time the mitochondrial volume density, the mean mitochondrial volume and surface areas, and the area of mitochondrial profiles were significantly decreased, whereas the mitochondrial envelope surface was not significantly altered. The findings indicate a rapid swelling, followed by disintegration of the mitochondria in the B-cells of alloxan-treated mice, thereby supporting our view that mitochondrial lesions play a primary role in the development of alloxan diabetes. These lesions are believed to be due to ionic alterations in the B-cells ("Pi-pH hypothesis").

P-Hydroxymercuribenzoate-induced hyperglycemia: influence of pre- and post-treatment with L-leucine, tolbutamide, D-mannoheptulose, insulin and alloxan

The aims were to see whether p-hydroxymercuribenzoate (PMB) administration affects the serum insulin concentration in mice in vivo, whether the transitory hyperglycemia induced in fed mice by treatment with PMB is affected by L-leucine, tolbutamide, D-mannoheptulose or insulin, and whether PMB affects the B-cell toxicity of alloxan. A significant decrease in the serum insulin concentration was found 1 and 2 h following PMB injection in fed and starved mice. PMB-induced hyperglycemia was abolished by pre-treatment with L-leucine and tolbutamide, but not by pre-treatment with D-mannoheptulose, or by post-treatment with insulin. Pre-treatment of fed mice with PMB caused potentiation of the initial hyperglycemia following alloxan, but inhibited the second hyperglycemic phase. These findings indicate that PMB treatment of mice has a transient inhibitory influence upon insulin secretion, and protects against the development of alloxan diabetes.

Inhibitory effect of diphenylhydantoin on the diabetogenic action of alloxan in the mouse.

The effect of the pretreatment of mice with diphenylhydantoin (DPH) on the development of alloxan diabetes was studied. DPH, in intraperitoneal doses of 20 to 45 mg./kg., administered one hour prior to alloxan, was found to prevent the development of alloxan (75 mg./kg., intravenously) diabetes. Administration of DPH after alloxan had no effect. The initial hyperglycemie response to alloxan (measured forty-five minutes post-alloxan) was potentiated by DPH pretreatment. Intravenous glutathione, administered one minute prior to alloxan, inhibited both the initial and chronic hyperglycemia produced by alloxan. A structural similarity between DPH and alloxan suggests that DPH may be protecting pancreatic beta cell binding sites from alloxan.

Diabetogenic action of alloxan following temporary interruption of arterial blood flow to pancreas in rats.

Ligation of the superior mesenteric and the superior pancreatico-duodenal arteries just prior to alloxan treatment and their release ten minutes after treatment did not protect rats against development of alloxan diabetes. Prior incubation of alloxan in vitro for a period of ten minutes at a physiological pH value and 37° C. resulted in loss of diabetogenic activity. Identical blood flow interruption without alloxan treatment did not produce elevated blood glucose levels. After the intravenous injection of alloxan, a substance giving a fluorescence product with alloxan reagent was detected in blood over four hours. The substance remained at higher levels when animals, prior to alloxan treatment, were injected with reduced glutathione. There was also a prolonged detection of alloxan during incubation in whole blood and in buffer containing reduced glutathione. The production of alloxan diabetes following temporary interruption of arterial blood flow is discussed in the light of the present results.

Changes in Plasma Immunoreactive Insulin Level during the Development of Alloxan Diabetes in Dogs

Changes in Plasma Immunoreactive Insulin Level during the Development of Alloxan Diabetes in Dogs

On the development of alloxan diabetes in mice

The development of alloxan diabetes in non-fasting mice of the NMRI strain was studied by measuring blood glucose, immunoassayable insulin. and liver glycogen levels. In addition the effects of tolbutamide and anti-insulin serum injections were studied. The results were as follows: 1) The initial hyperglycaemic phase following alloxan injection was accompanied by a highly significant decrease in plasma insulin levels and liver glycogen levels. Tolbutamide had no effect on the initial hyperglycaemia when given 5 min after alloxan, but greatly reduced the initial blood sugar level increase when given 5 min before alloxan. 2) The hypoglycaemic phase was accompanied by a marked rise in plasma insulin levels, which in the early phase showed a negative correlation with blood glucose levels. Liver glycogen levels increased towards normal values. The injection of anti-insulin serum 2 hr before the onset of the expected hypoglycaemia not only abolished the hypoglycaemic phase but was followed by a hyperglycaemia which surmounted the initial phase. 3) During the development of the permanent hyperglycaemic phase (studied 24 and 48 hr after alloxan injection) plasma insulin levels decreased gradually to subnormal or immeasurable values. Liver glycogen levels were highest 24 hr after alloxan injection and decreased only slowly during the following day. After 26 days, however, liver glycogen levels in alloxan diabetic mice were significantly lower than in normal mice, 24 hr after alloxan injection plasma insulin and blood glucose levels were inversely correlated. This was not the case after 48 hr or more. 4) During the stage of manifest alloxan diabetes, tolbutamide still had a slight but significant blood sugar lowering effect irrespective of the severity of the diabetic condition. The findings give strong evidence in mice of the correctness of the hypothesis of Iversen (1974) that the three phases of alloxan diabetes development are mainly due to a) insulin deficiency, b) insulin surplus, and c) insulin lack. During the first (hyperglycaemic) phase, however, a direct effect of alloxan on the liver appears to be present.

Influence of thyroid and adrenal gland on the development of alloxan diabetes from the view-point of serum Ca and Mg

Many evidences have been achieved since Gomori and Goldner had succeeded to generate alloxan diabetes. In these evidences it was observed that Ca and Mg in serum related closely to carbohydrate metabolism, especially to phosphous to metabolism, and from the fact that Ca in diabetic serum is observed as lower and Mg as higher, it is considerable that the determination of Ca and Mg in serum may be an index to infer the state of abnormal carbohydrate metabolism. On the ground of these evidences, I have investigated the variation of Ca and Mg in serum, and considered the influences on the alloxan diabetes at dysfunction of thyroid and adrenal gland. Examined animals were divided into 6 groups i.e., normal, thyroidectomized, thyradin injected, adrenalectomized, cortisone, injected, and cortisone injected and alloxanized group. Each group was injected with alloxan 200mg per kg of body weight, besides cortisone was injected i.m. 5mg per kg of body weight during 5 days, thyradin was injected i.m. 0.1mg during 5 days. From each group blood was picked up after allowan injection 2 hours, 5 hours, 8 hours, 1 days, 3 days, and 5 days, i.e., these pickup times are correspond to initial hyperglycemia stage, hypoglycemia stage, and durable hyperglycemia stage, then blood sugar and Ca and Mg in serum are determined about these pickuped blood. The results are summarized as follows. 1) In normal group, blood sugar curve shows the typical 3 phases, after 5 hours Ca and sugar in blood has mutually negative correlation and Mg has positive correlation with blood sugar. 2) In adreualectomized group, one does not recognize the first phase. Ca and Mg in serum only diminish. 3) In cortisone injected group, the first phase is prominent, and the development of hyperglycemia is easy, Ca and Mg alter like normal group, but the degree of alteration is more than that of normal group. 4) In cortisone injected and alloxanized group, hypoglycemia is slight, decrease of serum Ca appeares in the early stage and the degree of the decrease is larger. Mg in serum increase temporaly at hypoglycemia stage. 5) In thyradin injected group, hypoglycemia is severe and Ca in serum is similiar as that of the cortisone injected and alloxanized group. Mg in serum decreasat first and the 2nd phase then recovered. 6) In throidectmized group, the change of blood sugar is slight and hyperglycemia can not be observed, decrease of serum Ca is slight and after 3 days it recovers. The alteration of Mg goes parallel with blood sugar. 7) Except thyroidectmized group, Ca in serum decreases, and Mg in serum increases. 8) Hormons of thyroid gland and adrenal gland promot the development alloxan diabetes.

STUDIES ON PRODUCTION AND PREVENTION OF ALLOXAN DIABETES

From the following experimental results, it was suggested strongly that two systems other than the pancreas, the pituitaryadrenal system and autonomic nervous system, are also important in the pathogenesis of production and prevention of alloxan diabetes.1) 40mg/kg of alloxan was intravenously injected into rats of Wistar strain, and the development of alloxan diabetes was observed in 77%, 62 out of 80 rats.2) The pancreas in the rats that developed alloxan diabetes showed morphological changes such as reduction of the islets of Langerhans and destruction of β-cells. Biochemically, a decrease of glutathion content in the pancreas was observed.3) Alloxan diabetic rats showed a marked decrease of ascorbic acid content in the adrenal gland and a decrease in the number of circulating eosinophils, suggesting hyperfunction of the adrenal gland. Dysfunction of the autonomic nervous system was inplicated from a decrease of cholinesterase activity in plasma.4) In rats treated by 5mg/kg of intramuscular injection of chlorpromazine given 30 minutes prior to intravenous injection of 40mg/kg of alloxan, the development of alloxan diabetes was suppressed to 31%, 36 out of 117 rats, at 14°-16°C.5) In the cases in which the development of alloxan diabetes was prevented by chlorpromazine, the pathological changes in the pancreas was less marked and glutathion content in the pancreas were nearly normal.6) The premedicatian of chlorpromazine suppressed the decrease of ascorbic acid content in the adrenal gland and the decrease in the number of circulating eosinophils of alloxan treated rats. At the same time chlorpromazine showed inhibitory effect on the decline of plasma cholinesterase activity.7) Simultaneous intramuscular injection of 5 units of ACTH together with 5mg/kg of chlorpromazine could not prevent the development of diabetes caused by intravenous injection of 40mg/kg of alloxan given 30 minutes thereafter.

The preventive effect of glucagon (HGF) against the diabetogenic action of alloxan and its antagonism by insulin.

SUMMARY The intravenous injection of glucagon (0·4 mg/kg) 12–30 min before the administration of a diabetogenic dose of alloxan (60 mg/kg) prevents the development of alloxan diabetes in dogs. The protection obtained with glucagon is abolished by a subcutaneous injection of insulin (2 i.u./kg) administered 2 hr previously. The possible mechanism of this protection and of its antagonism by insulin is discussed.