Experimental pancreas transplantation: the consequences of the portocaval shunt on the blood glucose, plasma insulin, and glucagon

A proposição foi realizada, no período pós-operatório imediato, em 40 ratos Wistar, distribuídos por sorteio em doi grupos: grupo NC, vinte ratos correspondentes ao grupo controle, não diabético, submetidos a operação simulada e o grupo PT, 20 ratos correspondentes ao grupo diabético que recebeu transplante de pâncreas heterotópico de ratos Wistar normais. Durante sete dias, antes do transplante, e 1, 3, 6, 12, 24, 48, 72, 96 horas após, determinava-se a glicose sanguínea, a insulina plasnática e o glucagon. Estes parâmetros eram obtidos também do grupo NC. Diabetes mellitus experimental era induzida pela administração intravenosa de aloxana. O grupo PT era imunosuprimido com ciclosporina A. O grupo NC apresentou níveis normais de glicose sanguínea, de insulina plásmica e de glucagon, durante todo o experimento. Foi encontrada nítida hiperinsulinemia no sangue venoso periférico do grupo PT. A insulina plasmática era significantemente maior no grupo PT comparada ao grupo NC começando 72 horas após o transplante. O glucagon plasmático, elevado no período pré-transplante, não se alterou após o transplante. Apesar de hiperinsulinemia e hiperglucagonemia, os níveis de glicose sanguínea eram elevados 6 horas após o transplante e mantiveram-se normais após este período. Considerando-se os níveis de glicose sanguínea 12 horas pós-transplante, não houve diferença estatisticamente significante entre os grupos PT e NC, até o sacrifício.

Long-term effects of insulin therapy, islet transplantation, and pancreas transplantation in the prevention of glomerular changes in kidneys of alloxan-induced diabetic rats

Groups of inbred alloxan-induced diabetic rats were treated with insulin (I), islets (IT), or pancreas transplantation (PT). Nondiabetic (N) and untreated diabetic (D) control groups were concurrently included. Each group was divided into five subgroups of 10 rats and killed after follow-up of 1, 3, 6, 9, and 12 months. Clinical and laboratory parameters were recorded, and kidney ultrastructural and morphometric analyses performed in each 12-month subgroup, namely glomerular basement membrane (GM) thickening, podocyte number, and number/extension of slit diaphragms (S). Rats from the I group showed poor metabolic control of diabetes compared with N group control rats. However, successfully transplanted rats (IT and PT) had complete restoration to normal levels for all metabolic parameters. GM thickening was significantly higher in diabetic compared with control rats. In contrast, the numbers of podocytes and slits as well as slit extensions were significantly decreased. Insulin therapy did not prevent any alterations upon comparison of diabetic vs control rats. Despite good metabolic control in IT rats, the degree of kidney lesion control never compared with that achieved in PT rats. In this group all glomerular changes were similar to the age-dependent lesions observed in control rats. We conclude that either IT or PT may be a good option for diabetes treatment, although pancreas transplantation seems to be the most effective treatment to control chronic complications.

Effects of intravenous glucose infusion and nutritional balance on serum concentrations of nonesterified fatty acids, glucose, insulin, and progesterone in nonlactating dairy cows

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Plasma progesterone concentration in beef heifers receiving exogenous glucose, insulin, or bovine somatotropin

Three experiments were conducted to evaluate plasma concentrations of glucose, insulin, IGF-I, and progesterone (P4) in pubertal beef heifers receiving exogenous glucose, insulin, or sometribove zinc. All heifers used had no luteal P4 synthesis but received a controlled internal drug-releasing device containing 1.38 g of P4 to estimate treatment effects on hepatic P4 degradation. In Exp. 1, 8 pubertal, nulliparous Angus x Hereford heifers (initial BW = 442 +/- 14 kg; initial age = 656 +/- 7 d) were randomly assigned to receive, in a crossover design containing 2 periods of 10 h, intravenous (i.v.) infusions (10 mL) of insulin (1 mu g/kg of BW; INS) or saline (0.9%; SAL). Treatments were administered via jugular venipuncture in 7 applications (0.15 mu g insulin/kg BW per application) 45 min apart (from 0 to 270 min). Blood samples were collected immediately before each infusion as well as at -120, -60, 330, 390, and 450 min relative to the first infusion. Heifers receiving INS had greater (P < 0.01) plasma insulin, reduced (P <= 0.04) plasma glucose and IGF-I, and similar (P = 0.62) plasma P4 concentrations compared with SAL heifers. In Exp. 2, the same heifers were assigned to receive, in a similar experimental design as Exp. 1, i.v. infusions (10 mL) of 1) insulin (1 mu g/kg BW) and glucose (0.5 g/kg BW; INS+G) or 2) SAL. Heifers receiving INS+G had greater (P <= 0.02) plasma insulin, glucose, and P4 but reduced (P = 0.01) plasma IGF-I concentrations compared with SAL heifers. In Exp. 3, the same heifers were assigned to receive, in a crossover design containing 2 periods of 14 d, subcutaneous (s.c.) injections of 1) 250 mg of sometribove zinc (BST) or 2) SAL. Blood samples were collected 3 h apart (0900, 1200, 1500, and 1800 h) from heifers on d 6, 8, and 10 relative to treatment administration (d 1). Heifers receiving BST had greater (P < 0.01) plasma glucose and IGF-I and similar (P >= 0.67) plasma insulin and P4 concentrations compared with SAL heifers. Results from this series of experiments suggested that concurrent increases in glucose and insulin are required to reduce hepatic catabolism and increase plasma concentrations of P4 in bovine females.

Concentrations of Progesterone and Insulin in Serum of Nonlactating Dairy Cows in Response to Carbohydrate Source and processing

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Relative expression of insulin like growth factor I (IGFI) and follicle stimulating hormone receptor (FSHR) in follicles and ovarian tissue from Bos primigenius indicus (Nelore)

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Periodontal Disease Decreases Insulin Sensitivity and Insulin Signaling

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

NaF treatment increases TNF-alpha and resistin concentrations and reduces insulin signal in rats

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Effect of fluoride intake on carbohydrate metabolism, glucose tolerance, and insulin signaling

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Effects of fluoride intake on insulin sensitivity and insulin signal transduction

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Insulin signal decrease in muscle but not in the liver of castrated male rats from chronic exposure to fluoride

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The influence of short-term diabetes mellitus and insulin therapy on alveolar bone loss in rats

Background: It is well known that the multiple direct and indirect consequences of hyperglycemia in diabetic individuals have been linked to a number of abnormal host effector mechanisms that could lead to an increased risk of developing periodontal disease.Objective: the aim of this study was to investigate the effect of short-term experimental diabetes and insulin therapy on the severity of alveolar bone loss in rats, and the effect of experimental periodontitis on glycemic control.Methods: Seventy-two male Wistar rats were divided into four groups: group I animals were submitted to dental ligature around lower right first molars (ligated); group II consisted of streptozotocin (STZ)-diabetic, ligated rats; group III represented STZ-diabetic, unligated rats; and group IV consisted of insulin-treated (6 U/day), STZ-diabetic, ligated rats. Blood glucose of all diabetic rats was monitored at regular intervals. Standardized digital radiographs were taken after killing at 7, 15 and 30 days to measure the amount of bone loss about the mesial root surface of the first molar tooth in each rat.Results: No significant (p < 0.05) changes in plasma glucose levels of insulin-treated diabetic rats were found among the different examinations after the beginning of insulin therapy. Rats from group II showed significantly greater increases in mean plasma glucose levels at 15 and 30 days after ligature placement compared with rats from group III (p < 0.05). Furthermore, in spite of the significant alveolar bone loss progression that was observed in groups I, II and IV (p < 0.00001; two-way ANOVA), no significant differences among these groups regarding the severity of bone loss (p = 0.77) and no significant interaction between treatment group and time (p = 0.81) were found.Conclusions: Within the limits of this study, it can be suggested that the severity of periodontal disease was not affected by short-term diabetes, and that experimental periodontitis increased blood glucose levels in uncontrolled diabetic rats.

Effect of diabetes mellitus and insulin therapy on bone density around osseointegrated dental implants: a digital subtraction radiography study in rats

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