Tissue contents and subcellular distribution of chromium and other trace metals in experimental diabetic rats after intravenous injection of Cr 50-enriched stable isotopic tracer solution

The Potential of Cr3 [Triaqua-μ3 -Oxo-Hexa-μ-Propionatotrichromium(III) Chloride] to Reduce Birth Defects in the Offspring of Diabetic CD-1 Mice

Diabetes mellitus is a growing concern worldwide and leads to multiple complications during pregnancy. Pharmacologic doses of chromium (Cr) have been linked with improving insulin sensitivity and other positive benefits in the treatment of diabetes in animal models. By using streptozotocin induced hyperglycemia in female CD-1 mice, reproductive outcomes of diabetic and chromium-dosed diabetic females were examined. After dosing 10 mg/kg Cr in the form of triaqua-μ3 -oxo-hexa-μ-propionatotrichromium(III) chloride or Cr3 during gestation days 8-16 (GD8-GD16), all females were sacrificed on gestation day 17 (GD17) and examined for maternal weight gain. The fetuses were examined for gross malformations and for skeletal malformations. The offspring of Cr3-dosed females tended to have a reduction in the incidence of supernumerary ribs. While hyperglycemia still had negative impacts on the health of dams and their offspring, administration of Cr led to an apparent trend in the reduction in the number of malformations and incidence of supernumerary ribs compared to those of untreated diabetic mothers.

Alterations in kidney tissue following zinc supplementation to STZ-induced diabetic rats

Diabetes mellitus is a chronic disease characterized by anomalies forming in carbohydrate, lipid, protein metabolisms and the incidence of this disease varies widely throughout the world. Zinc is an important element which is essential for life and is present in nature. In this study, the animals were divided into four groups. These groups were named as untreated; zinc sulfate; streptozotocin (STZ); STZ and zinc sulfate. STZ (65 mg/kg) was dissolved in a freshly prepared 0.01 M pH 4.5 citrate buffer and given with intraperitoneal injection in a single dose. Zinc sulfate (100mg/kg) was dissolved in distilled water and given to the animals by gavage at a daily dose for 60 days. The rats were sacrificed under ether anesthesia. This study was aimed to investigate histological and biochemical changes of zinc supplementation on the kidney tissue in STZ-induced diabetic rats. In the current study, histological and histochemical observations showed that the occurred degenerative changes decreased after giving zinc in the kidney tissue of diabetic group. Kidney glutathione (GSH) levels decreased and lipid peroxidation (LPO), nonenzymatic glycosylation (NEG), urea and creatinine levels increased in diabetic rats. GSH levels increased, while LPO, NEG, urea and creatinine levels decreased in the kidney with administration of zinc to diabetic rats. As a result, we observed curative effects of zinc given to diabetic rats. We can say that zinc may be an important antioxidant for the treatment of secondary complications of diabetes in kidney tissue.

Consequences of a fat diet in the distribution of minerals within pancreatic tissues of rats and rabbits

The effects of plasma lipid overload on pancreatic islet function and on mineral imbalance are issues under debate. However, the outcomes may be biased by the different metabolisms of different species. This prospective study evaluated whether a high fat diet intake changed the distribution of physiologically relevant elements within pancreatic endocrine and exocrine tissues of Sprague Dawley rats and New Zealand White rabbits. Nuclear microscopy techniques provided images of the specimen density and structure as well as the elemental distributions and quantification of P, S, Cl, K, Ca, Fe, and Zn using unstained cryosections of pancreas. Our results indicate that pancreatic islets in normal rats and rabbits had lower tissue density and higher Ca, Fe, and Zn content compared to exocrine tissue, and that rabbit islets exhibit the highest Zn content (3,300 μg/g in rabbits versus 510 μg/g in rats). Fat diet intake resulted in large deposits of fat in the pancreas, which modified the density contrast of tissues and also resulted in a twofold decrease of Ca and Zn concentrations in islets of both rats and rabbits. This result indicates that a fat diet leads to a reduction in essential trace element concentrations in pancreas, which in turn may hamper endocrine function.

Effects of Juniperus oxycedrus ssp. oxycedrus on tissue lipid peroxidation, trace elements (Cu, Zn, Fe) and blood glucose levels in experimental diabetes

ETHNOPHARMACOLOGICAL RELEVANCE

Juniperus oxycedrus L. (Cupressaceae) fruits and leaves are used internally and pounded fruits are eaten for diabetes in Turkey.

AIM OF THE STUDY

To evaluate the interrelationships between the levels of chosen trace elements (copper, iron, and zinc) and hepatic, renal lipid peroxidation (TBARS) in streptozotocin-induced diabetic rats treated with Juniperus oxycedrus ssp. oxycedrus (J.o.s.o.) leaf and fruit extracts for 10 days.

MATERIALS AND METHODS

J.o.s.o. fruit and leaf extracts were administered in STZ-induced diabetic rats, at doses of 500 and 1000 mg/kg. The blood glucose levels were measured in the 1st, 4th, 7th and 10th day of experiment. Fe, Cu, and Zn contents and lipid peroxidation levels of liver and kidney tissues were determined by atomic absorption spectrophotometry and ultraviolet spectrophotometry, respectively.

RESULTS

Treatment of diabetic rats with the J.o.s.o. fruit and leaf extracts decreased the blood glucose levels and both the levels of lipid peroxidation in liver and kidney tissues. J.o.s.o. extracts have augmented Zn concentrations in liver of STZ-induced diabetic rats.

CONCLUSIONS

Results indicated that J.o.s.o. fruit and leaf extracts might be beneficial for diabetes and its complications.

The effects of chromium histidinate on mineral status of serum and tissue in fat-fed and streptozotocin-treated type II diabetic rats

The present study was conducted to investigate the effects of chromium histidinate (CrHis) against experimentally induced type II diabetes and on chromium (Cr), zinc (Zn), selenium (Se), manganese (Mn), iron (Fe), and copper (Cu) in serum, liver, and kidney of diabetic rats. The male Wistar rats (n = 60, 8 weeks old) were divided into four groups. Group I received a standard diet (12% of calories as fat); group II were fed standard diet and received CrHis (110 mcg CrHis/kg body weight per day); group III received a high-fat diet (HFD; 40% of calories as fat) for 2 weeks and then were injected with streptozotocin (STZ) on day 14 (STZ, 40 mg/kg i.p.; HFD/STZ); group IV were treated as group III (HFD/STZ) but supplemented with 110 mcg CrHis/kg body weight per day. The mineral concentrations in the serum and tissue were determined by atomic absorption spectrometry. Compared to the HFD/STZ group, CrHis significantly increased body weight and reduced blood glucose in diabetic rats (p < 0.001). Concentrations of Cr, Zn, Se, and Mn in serum, liver, and kidney of the diabetic rats were significantly lower than in the control rats (p < 0.0001). In contrast, higher Fe and Cu levels were found in serum and tissues from diabetic versus the non-diabetic rats (p < 0.001). Chromium histidinate supplementation increased serum, liver, and kidney concentrations of Cr and Zn both in diabetic and non-diabetic rats (p < 0.001). Chromium supplementation increased Mn and Se levels in diabetic rats (p < 0.001); however, it decreased Cu levels in STZ-treated group (p < 0.001). Chromium histidinate supplementation did not affect Fe levels in both groups (p > 0.05). The results of the present study conclude that supplementing Cr to the diet of diabetic rats influences serum and tissue Cr, Zn, Se, Mn, and Cu concentrations.

Zinc and diabetes--clinical links and molecular mechanisms

Zinc is an essential trace element crucial for the function of more than 300 enzymes and it is important for cellular processes like cell division and apoptosis. Hence, the concentration of zinc in the human body is tightly regulated and disturbances of zinc homeostasis have been associated with several diseases including diabetes mellitus, a disease characterized by high blood glucose concentrations as a consequence of decreased secretion or action of insulin. Zinc supplementation of animals and humans has been shown to ameliorate glycemic control in type 1 and 2 diabetes, the two major forms of diabetes mellitus, but the underlying molecular mechanisms have only slowly been elucidated. Zinc seems to exert insulin-like effects by supporting the signal transduction of insulin and by reducing the production of cytokines, which lead to beta-cell death during the inflammatory process in the pancreas in the course of the disease. Furthermore, zinc might play a role in the development of diabetes, since genetic polymorphisms in the gene of zinc transporter 8 and in metallothionein (MT)-encoding genes could be demonstrated to be associated with type 2 diabetes mellitus. The fact that antibodies against this zinc transporter have been detected in type 1 diabetic patients offers new diagnostic possibilities. This article reviews the influence of zinc on the diabetic state including the molecular mechanisms, the role of the zinc transporter 8 and MT for diabetes development and the resulting diagnostic and therapeutic options.

Study of chromium-containing proteins in subcellular fractions of rat liver by enriched stable isotopic tracer technique and gel filtration chromatography

Ten male Wistar rats were intravenously injected with a single approximately physiological dose of enriched stable isotopic Cr-50 tracer solution (200 ng (50)Cr(3+)/100 g body wt). The fundamental distribution patterns of the chromium-containing proteins in the nucleic, mitochondrial, lysosomal, microsomal, and cytosolic subcellular fractions of the rat liver were investigated by means of Sephadex G-100 gel chromatography combined with neutron activation analysis via (50)Cr (n, gamma) (51)Cr reaction. In total, nine kinds of Cr-containing proteins were found in the five subcellular fractions, whose relative molecular masses were 96.6+/-6.2, 68.2+/-1.4, 57.9+/-4.7, 36.6+/-1.2, 24.2+/-1.8, 14.0+/-1.5, 8.8+/-0.6, 6.9+/-0.4, and 4.2+/-0.4 kDa. Approximately 64.5% of Cr proteins accumulated in the cytosolic fraction. The second enriched part was the nucleic fraction; about 12.2% Cr proteins were stored in this section. The 4.2-kDa molecular mass might contain the so-called low molecular weight chromium-containing substance; however, in this research, it was only observed in the mitochondria, lysosome, and microsome. In the mitochondrial fraction, most of the Cr proteins were present as relatively low molecular weight substances: about 56% of chromium-containing proteins had molecular masses < or =6.9 kDa. Nevertheless, more than 69% of Cr-containing proteins were observed with molecular masses > or =57.9 kDa in the liver cytosolic fraction.