Insulin degludec and glutamine dipeptide modify glucose homeostasis and liver metabolism in diabetic mice undergoing insulin-induced hypoglycemia

This study investigated whether a 30-day co-treatment with 1 g/kg glutamine dipeptide (GdiP) and 1 U/kg regular (rapid acting) or 5 U/kg degludec (long acting) insulins modifies glucose homeostasis and liver metabolism of alloxan-induced type 1 diabetic (T1D) male Swiss mice undergoing insulin-induced hypoglycemia (IIH). Glycemic curves were measured in fasted mice after IIH with 1 U/kg regular insulin. One hour after IIH, the lipid profile and AST and ALT activities were assayed in the serum. Morphometric analysis was assessed in the liver sections stained with hematoxylin-eosin and glycolysis, glycogenolysis, gluconeogenesis and ureagenesis were evaluated in perfused livers. T1D mice receiving GdiP or the insulins had a smaller blood glucose drop at 60 minutes after IIH, which was not sustained during the subsequent period up to 300 minutes. The 30-day treatment of T1D mice with insulin degludec, but not with regular insulin, improved fasting glycemia, body weight gain and serum activity of AST and ALT. Treatments with insulin degludec, GdiP and insulin degludec + GdiP decreased the liver capacity in synthesizing glucose from alanine. GdiP, in combination with both insulins, was associated with increases in the serum triglycerides and, in addition, regular insulin and GdiP increased AST and ALT activities, which could be the consequence of hepatic glycogen overload. GdiP and the insulins improved the IIH, although to a small extent. Caution is recommended, however, with respect to the use of GdiP because of its increasing effects on serum triglycerides and AST plus ALT activities.

Gold-based nanospheres and nanorods particles used as theranostic agents: An in vitro and in vivo toxicology studies

The adverse effect of gold-based nanoparticles is still an open question since it depends on several factors as shape, surface charge or route of administration. In this study, we investigated the influence of shape and human serum albumin (HSA) coating on the adverse effects of spherical (AuNP) and nanorods (AuNR) gold-based particles. F C3H (fibroblast) and HTC (hepatocellular carcinoma) cell lines both from liver were exposed to 25, 75 and 125 μg mL^-1, which correspond to 10⁹ NP mL^-1. For in vivo studies, Wistar rats received these materials by oral administration in doses of 10 μg kg^-1 or 40 μg kg^-1. Systemic toxicity was verified after 24 h and 48 h by morphological analysis, blood parameters and myeloperoxidase enzyme activity. Our results revealed that HSA corona does not influence totally the pathway of interactions between AuNP and AuNR. In vitro results evidenced that AuNP can decrease in at least 50% viability of F C3H and cell adhesion of HTC, but corona significantly overcomes these effects. No differences between shape or corona were observed in function of cell lines. In vivo studies showed that 40 μg kg^-1 of AuNP-HSA caused an enhancement of the myeloperoxidase response indicating inflammatory processes. An increase from 40% to 80% on alkaline phosphatase levels were found for all groups. Our findings suggested that gold-based particles coated or not with HSA do not cause expressive adverse effects on in vitro or in vivo systems, and their oral administration cannot cause a systemic effect in the experimental conditions used here.

Supplementation of Glutamine and Vitamin E on the Morphometry of the Intestinal Mucosa in Broiler Chickens

The objective of this experiment was to evaluate the influence of Gln and vitamin E (VE) supplementation in the diet of broiler chickens (Cobb-Vantress) on the morphometry of the intestinal mucosa. The design was completely randomized in a 2 x 3 (VE x periods of administering Gln) factorial arrangement. The levels of VE used were 10 and 500 mg/kg of diet and 3 periods of administering (1%) Gln-supplemented starter diet (for the first 7 or 14 d of life or for no added Gln), totaling 6 treatments with 5 replicates of 50 birds per experimental unit. In the growth period (d 22 to 41 posthatch), the treatments consisted only in the respective levels of VE. On d 7, 14, 21, and 41 posthatch, 2 birds per replicate were killed, and samples of the duodenum, jejunum, and ileum were subsequently removed, fixed in Bouin solution, and later embedded in paraffin and stained with hematoxylin-eosin. The parameters analyzed were villus height and crypt depth. An ANOVA was applied to the obtained data, and the means were compared using Tukey's test (5% significance level). Greater development was observed in the duodenum, followed by the jejunum and ileum. On 41 d of life, diets with 10 mg of VE/kg supplemented with Gln (for the first 7 d of life) provided better development of the intestinal mucosa in broiler chickens.

Effects of a hypoproteic diet on myosin-V immunostained myenteric neurons and the proximal colon wall of aging rats

The objective of this work was to analyze the morphoquantitative behavior of neurons of the myenteric plexus, as well as the morphometry of elements of the proximal colon wall of Wistar rats (Rattus norvegicus) fed a normoproteic (22%) and a hypoproteic (8%) diet, and sacrificed at 360 days of age. To perform the neuronal evaluation, we used whole-mount preparations of the proximal colon immunostained with the antibody anti-myosin-V. The neurons were quantified in 80 microscopic fields (16.98 mm(2)/animal). The neuronal cell body morphometry was performed in 100 neurons/animal. Samples of the proximal colon were weighed and measured, and then submitted to routine histological processing. They were later stained using the hematoxylin--eosin method in order to carry out morphometric analysis on the mucosa and external muscular layers. The number of neurons and the neuronal cell body morphometry did not present significant differences between the studied groups. A significant reduction in the weight and length of the proximal colon and in mucosa layer thickness was observed in the animals fed with the hypoproteic diet. We concluded that the neuronal and non-neuronal components of the proximal colon adapted to the imposed nutritional condition, which guaranteed the maintenance of their functions.

Morphometric and quantitative evaluation of the NADH-diaphorase positive myenteric neurons of the jejunum of streptozotocin-diabetic rats supplemented with acetyl-L-carnitine

Summary In this study we investigated the effect of the acetyl-L-carnitine (ALC) supplementation on the myenteric neurons of the jejunum of rats made diabetic at the age of 105 days by streptozotocin (35 mg/kg body weight). Four groups were used: non-diabetic (C), non-diabetic supplemented with ALC (CC), diabetic (D), diabetic supplemented with ALC (DC). After 15 weeks of diabetes induction the blood was collected by cardiac puncture to evaluate glycaemia and glycated haemoglobin. Next the animals were killed and the jejunum was collected and subjected to whole-mount preparation to evidence the myenteric neurons through the histochemical technique of the NADH-diaphorase. The neuronal counts were made in 80 microscopic fields, in tissue samples of five animals of each group. The profiles of the cell bodies of 1000 neurons per group were analysed. Diabetes induced a significant increase in the area of the cell body and decrease in the number of NADH-diaphorase positive myoenteric neurons. ALC suplementation to the diabetic group promoted smaller hypertrophic effects and less neuronal loss than in the myoenteric neurons of the diabetic rats, and in addition diminished the body weight decrease and reduced the fasting glycaemia.