Analysis of zinc and other elements in rat pancreas, with studies in acute pancreatitis

Zinc: Roles in pancreatic physiology and disease

Zinc is an essential trace element. Deficiencies are frequently seen with gastrointestinal diseases, including chronic pancreatitis, nutritional deficiency, and reduced intestinal absorption. Additionally, reduced zinc levels have been linked to cellular changes associated with acute pancreatitis such as enhanced inflammation with increased macrophage activation and production of inflammatory cytokines such as IL-1β, impaired autophagy, and modulation of calcium homeostasis. Preliminary data suggest that zinc deficiency may lead to pancreatic injury in animal models. The purpose of this review is to explore the biologic effects of zinc deficiency that could impact pancreatic disease. MESH KEYWORDS: Malnutrition, inflammation, trace element.

Toxicity of organic and inorganic nickel in pancreatic cell cultures: Comparison to cadmium

Nickel compounds are Group 1 carcinogens and possibly cancer-causing in the pancreas. We examined the toxicity of nickel in both 2-D and 3-D pancreatic cell cultures, to determine the LD50 for organic and inorganic nickel in normal and cancerous cells. Assays with cadmium chloride were performed to be a comparison to potential nickel-induced toxicity. Cells were exposed to twelve concentrations of NiCl2 or Ni-(Ac)2 for 48h (2-D), or six concentrations for 48 hours (3-D). There was a significant (P=0.0016) difference between HPNE and AsPC-1 LD50 values after cadmium exposure, at 69.9 µM and 29.2 µM, respectively. Neither form of nickel exhibited toxicity in 2-D or 3-D cultures, but after 48h, changes in spheroid morphology were observed. The inability of Ni to reduce viable cell numbers suggests a toxic mechanism that differs from cadmium, also a Group 1 carcinogen. The cell microenvironment was not a factor in nickel toxicity with no changes in viable cells in either 2-D or 3-D cultures. These studies only examined cytotoxicity, and not genotoxicity, a potential mechanism of nickel carcinogenicity. Alterations in DNA function or the expression of apoptotic proteins/processes would take longer to manifest. Current work focuses on cellular changes following extended nickel exposure.

The antioxidant profiles, lysosomal and membrane enzymes activity in patients with acute pancreatitis

Oxidative stress and inflammatory mediators, such as IL-6, play an important role in the pathophysiology of acute pancreatitis. The study was aimed to assess the degree of the pro/antioxidative imbalance and estimate which antioxidant plays a role in the maintenance of pro/antioxidative balance during acute pancreatitis. The study was investigated in the blood of 32 patients with acute pancreatitis and 37 healthy subjects. IL-6 concentration as early marker of inflammation was determinated. The intensity of oxidative stress was assessed by TBARS concentration. To investigate antioxidative status, the GPx and Cu/Zn SOD activities and the levels of GSH, MT, SH groups, and TRAP were measured. The concentrations of Cu and Zn as ions participating in the maintenance of antioxidant enzymes stability and playing a role in the course of disease were determinated. The activities of GGT, AAP, NAG, and β-GD as markers of tissue damage were also measured. An increase in IL-6 concentration, which correlated with Ranson criteria, and an increase in GPx activity, levels of MT, TBARS, or GGT, and NAG activities in patients group compared to healthy subjects were demonstrated. A decrease in GSH level in patients group compared to control group was noted. The studies suggest that GPx/GSH and MT play the role of the first line of defence against oxidative stress and pro/antioxidant imbalance in the course of acute pancreatitis.

Participation of metallothionein and superoxide dismutase in the blood of smoking smelters

OBJECTIVES

Metallothionein (MT) and two forms of superoxide dismutase (SOD), which are dependent on zinc and copper ions, are involved in defense against the same superoxide anion radicals and are present in extra- and intracellular compartments. The aim of our study was to investigate MT concentration and Cu/Zn SOD activity in the plasma and erythrocyte lysate of the non-smoking and smoking smelters.

MATERIAL AND METHODS

The investigations were performed in the blood of 300 male smelters and 100 non-exposed male subjects. We have measured zinc, copper, malondialdehyde (MDA) and MT concentrations as well as SOD activity.

RESULTS

We have observed an increase of Cu/Zn coefficient and decrease of Zn/Cu coefficient in the serum of smelters in comparison with the non-smoking control group. Concentration of MDA in the plasma of smelters was higher in comparison with its concentration in the non-smoking control group. The plasma and the erythrocyte lysate MT concentration increased significantly in the whole group of smelters as compared to the non-smoking control group. The mean value of MT concentration in plasma of the smoking smelters was above 2-fold higher than in the non-smoking control group. The activity of Cu/Zn SOD in plasma of the smoking and non-smoking smelters was decreased in comparison with the smoking and non-smoking control groups, respectively. The lowest activity of Cu/Zn SOD, about 2-3-fold decreased in comparison with the smoking and non-smoking control groups, was detected in plasma of the smelters. An inverse relationship was observed in the erythrocyte lysate. The highest activity of Cu/Zn SOD was reported in the erythrocyte lysate of the smoking smelters and it was about 2-fold higher than in the non-smoking control group.

CONCLUSIONS

In extracellular environment MT plays a crucial role in comparison with the SOD, while in the intracellular compartment Cu/Zn SOD and MT cooperate with each other.

Change of zinc, copper, and metallothionein concentrations and the copper-zinc superoxide dismutase activity in patients with pancreatitis

OBJECTIVES

The aims of the present studies were to measure the concentrations of zinc (Zn), copper (Cu), and metallothionein and the Cu/Zn superoxide dismutase activity as elements engaged in an essential manner in the prooxidative and antioxidative balance of organism and to demonstrate the degree to which metallothionein and Cu/Zn superoxide dismutase are involved in the inflammatory processes occurring in the pancreas.

METHODS

The concentration of metallothionein was measured by immunoenzymatic method. Serum Cu/Zn superoxide dismutase activity was determined using a commercial test. The measurements of Zn and Cu concentrations in serum were assessed with the use of flame atomic absorption spectrometry.

RESULTS

Lowered serum Zn concentration and higher Cu level were observed in the serum of patients with chronic exacerbated pancreatitis and chronic pancreatitis. The significant increase of metallothionein concentration and Cu/Zn superoxide dismutase activity was observed in the blood of patients with chronic exacerbated pancreatitis and chronic pancreatitis. In slices of the pancreas during pancreatitis, we observed in immunohistochemical reaction the variable involvement of Cu/Zn superoxide dismutase and metallothionein.

CONCLUSIONS

The results presented in these studies indicate an essential and variable involvement of antioxidants such Cu/Zn superoxide dismutase and metallothionein and disordered Cu and Zn homeostasis depending on the progression of inflammatory processes in patients with pancreatitis.

Attenuation of Zn-induced acute pancreatitis in Wistar rat fed on Cu- and Mg- enriched modified poultry egg Psi

Zinc (Zn) consumption has increased in many populations either due to the increased intake of Zn-fortified foods as in the USA or in agricultural food stuffs as in some Indian states during the last decade. Its excessive intake has been reported to induce acute pancreatitis (AP) in many studies due to increase in oxidative stress that was further reported to cause Cu and Mg deficiencies. This led us to design a modified poultry egg (ME(Psi)) enriched with Cu and Mg along with other antioxidants, and its efficacy on Zn-induced AP was studied in male Wistar rats. In one set, the rats were fed on equacaloric semi-synthetic basal diet containing 20 mg Zn/kg diet (control, group I), and Zn-induced AP-I diet and AP-II diet containing 40 and 80 mg Zn/kg diet (groups II and III) for 180 days, respectively. In another set, the rats were initially fed on Zn-induced AP-I and AP-II diets for 90 days and then shifted to ME(Psi)-mixed Zn-induced AP-I and AP-II diets in groups IIME and IIIME for another 90 days. At the end of the experiment, data displayed increased serum and urinary Zn, Cu, and Mg levels in groups II and III rats, which were reduced and approached closer to control group I after ME(Psi) feeding in groups IIME and IIIME rats. Transmission electron microscopic studies of acinar cells revealed progressive dilation, vesicularization, and degeneration of endoplasmic reticulum (ER), and decrease in zymogen granules (ZG) in groups II and III rats in contrast to their curvilinear or concentric long parallel running cisternal profile of ER in control group I. The treatment of ME(Psi) helped in the restoration of the ER profile and ZG number, approaching closer to the control group I. The degree of recovery was dependent upon the degree of toxicity caused by the amount of Zn given in the diet. The results of this study suggest that ME(Psi)-mixed diet can protect the acinar cells from the deleterious effects of Zn by decreasing the oxidative stress.

Relationships among iron, protein oxidation and lipid peroxidation levels in rats with alcohol-induced acute pancreatitis

It has been previously shown that alcohol induces the damage of pancreatic parenchyma tissue, but the mechanism of this damage is still poorly understood. Assuming that oxygen radical damage may be the involved, we measured markers of oxidative damage in pancreatic tissue, blood serum, plasma, and whole blood of rats with early-stage alcohol-induced acute pancreatitis. Thirty-eight male Wistar rats were divided into three groups: the control group (group 1), the acute pancreatitis group 1 day (group 2), and 3 days (group 3) after the injection of ethyl alcohol into the common biliary duct, respectively. The levels of Fe in tissue and serum, whole blood viscosity, plasma viscosity, fibrinogen and homocysteine (Hcy) levels, erythrocyte and plasma malondialdehyde (MDA), and tissue and plasma protein carbonyl levels were found to be significantly higher in groups 2 and 3 than in group 1. However, the levels of reduced glutathione (GSH) in tissue and erythrocytes were significantly lower in groups 2 and 3 than in group 1. These results suggest that elevated Fe levels in serum and pancreatic tissue in rats with early-stage alcohol-induced acute pancreatitis is associated with various hemorheological changes and with oxidative damage of the pancreas.

Coxsackievirus B3 infection affects metal-binding/transporting proteins and trace elements in the pancreas in mice

OBJECTIVE

The trigger of juvenile diabetes has been suggested to be an interaction between a virus and trace elements, where enteroviruses, including coxsackievirus B3 (CVB3), have been discussed as potential initiators. The aim of this study was to investigate the effects in the pancreas on gene expressions of metallothionein 1 (MT1), divalent metal transporter 1 (DMT1), and zinc transporter 5 (ZnT-5) and concomitant changes in iron (Fe), copper (Cu), and zinc (Zn) in serum and pancreas of Balb/c mice on days 3, 6, and 9 of CVB3 infection.

METHODS

Trace elements were measured through inductively coupled plasma-mass spectrometry, and CVB3, MT1, DMT1, and ZnT-5 were measured by reverse transcription-polymerase chain reaction.

RESULTS

Virus was found in the pancreas on all days, with a peak on day 3. Infection tended to increase Fe in both serum and the pancreas. The Cu/Zn ratio in the pancreas increased early in the infection because of a great decrease in Zn. In serum, the Cu/Zn ratio was not increased until day 9 of the disease. In the pancreas, MT1 decreased, whereas DMT1 tended to increase on day 6, and ZnT-5 increased progressively during the course of the disease.

CONCLUSIONS

Virus-induced changes in trace elements, MT1, DMT1, and ZnT-5 in the pancreas may reflect early stages of the development of pancreatitis and prestages of diabetic disease.

Trace element changes in the pancreas during viral infection in mice

INTRODUCTION

The trigger for some cases of juvenile diabetes has been suggested to be an interaction between a virus and various trace elements. Infection with human coxsackievirus B3 (CB3) in the murine model results in viral replication and inflammation in the pancreas.

AIM

To determine how infection affects the trace element balance in the pancreas.

METHODOLOGY

Concentrations of the following trace elements were measured in the serum and pancreas during the early phase (days 1 and 3) of CB3 infection in female Balb/c mice: aluminium, arsenic, cadmium (Cd), calcium (Ca), cobalt (Co), copper (Cu), iron (Fe), lead (Pb), magnesium (Mg), manganese (Mn), mercury (Hg), selenium, silver, vanadium (V), and zinc (Zn). The trace element concentrations were measured through inductively coupled plasma mass spectrometry. The histopathology was established by hematoxylin-eosin techniques and immunohistochemical staining of both CD4 and CD8 cells of the pancreas.

RESULTS

Infected mice developed expected clinical signs of disease. The only changes at day 1 occurred in the serum, with a pronounced decrease in the Zn concentration and a small increase in the V concentration. At day 3, concentrations of several trace elements, including Cu, Zn, Fe, Ca, V, and Mn, showed pronounced changes in both the serum and the pancreas. Ca, Cu, Mg, Mn, and V, but none of the potentially toxic elements, accumulated in the pancreas. Cu and V concentrations increased in the serum as well.

CONCLUSION

Several trace element changes, preceding the development of pancreatitis, occurred in the pancreas in this viral infection, the exact pathogenic interpretation of which warrants further studies.