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Objective: The aim of this study was to evaluate in vivo the effects of cadmium and zinc ions on translational machinery and death of mouse liver cells., Material and Methods: Outbred mice received intraperitoneal injections of cadmium chloride solution (1.4 micromoles cadmium per 1 kg of body weight) and/or zinc sulfate solution (4.8 micromoles zinc per kg of body weight) three times per week for six weeks. Analogical volume of saline solution was injected to the control mice. Protein synthesis was evaluated by incorporation of [(14)C]-labeled leucine into peptides and proteins. Total tRNAs were isolated using deproteinized extract of liver tissue. Postmitochondrial supernatant was as a source of leucyl-tRNA synthetase. Activities of tRNA(Leu) and leucyl-tRNA synthetase were measured by an aminoacylation reaction using [(14)C]-labeled leucine. Liver cell apoptosis was detected by TUNEL assay using in situ cell death detection kit., Results: A decrease in incorporation of [(14)C]-labeled leucine into proteins was detected in liver, kidney, and heart as well as diminution of tRNA(Leu) acceptor activity in cadmium-exposed liver. Cadmium caused activation of the leucyl-tRNA synthetase and induced liver cell apoptosis. Pretreatment of mice with zinc sulfate solution favored to protection of protein synthesis and acceptor activity of tRNA(Leu) against cadmium-induced inhibition. Under co-exposure of mouse liver to cadmium and zinc, activity of the leucyl-tRNA synthetase was at the level of control. Zinc did not influence TUNEL-positive cell number in cadmium-exposed mouse liver., Conclusions: Under subacute intoxication of mice by cadmium, zinc ions protect the translation machinery against inhibition, but do not decrease the number of apoptotic cells in the liver.

Cadmium (Cd(2+)) is an important industrial pollutant, although its mechanism of toxicity has not been completely clarified. Cd(2+) is toxic to a wide range of organs and tissues, however, the primary target organs of Cd(2+) toxicity are the liver and kidney. Echinacea purpurea stimulating one or another tread of the immune system stimulates the expression of immunoglobulins and interferons. The experiments were performed on white laboratory mice using intraperitoneal (i.p.) injections 0.05 LD(50) amount of CdCl(2) solution. Two groups of mice were injected by Echinacea purpurea liquid extract: one 0.05 LD(50) and the other 0.1 LD(50). In this article, the Cd(2+) distribution in internal organs, its effect on the mitotic and apoptotic activity of liver cells, as well as effects of Echinacea purpurea liquid extract on Cd(2+)-induced changes in mice were investigated. Cd(2+) concentration in mice blood, liver, and kidney was detected by atomic absorption spectroscopy. Long-term injections of extract of Echinacea purpurea combined with Cd(2+)Cl(2) leads to the significant increase of Cd(2+) concentration in blood and investigated organs of experimental mice. Mitotic and apoptotic activity of liver cells was expressed as the estimated number of mitotic and apoptotic liver cells in randomly selected reference areas in histological slide. Echinacea purpurea decreases the mitotic activity of liver cells induced by Cd(2+) and increases apoptotic activity of the liver cells.

We assessed the efficiency of detecting myocyte apoptosis within human hearts using in situ enzymatic reactions in paraffin-embedded tissue samples: in situ end labeling (ISEL), terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling (TUNEL), and in situ oligoligation (ISOL). The reactions were carried out in explanted hearts (idiopathic dilatative cardiomyopathy, n = 6; ischemic heart disease, n = 3) and in endomyocardial biopsy specimens (EMBs; n = 32) obtained from transplanted human hearts. The results were verified by DNA laddering. The ISOL reaction led to a significantly (P = .027) smaller number of false-positive results (2/41 [5%]) compared with assessment by ISEL (9/41 [22%]) or TUNEL (9/41 [22%]). Only 1 ISEL+ apoptotic cardiomyocyte was found in specimens from explanted hearts. Among the EMBs, 1 specimens had TUNEL+ apoptotic cardiomyocytes and 1 specimen had ISEL+ apoptotic cardiomyocytes. This implies that verifying results by independent methods must be used for TUNEL and ISEL techniques. A smaller number of false-positive results makes interpretation of ISOL results easier, although the sensitivity of this reaction remains to be established.

Numerous recent investigations on the development and morphology of atherosclerotic lesions have shown programmed cell death or apoptosis to be an important factor in atherogenesis. Enzymes known as caspases are essential for completion of the apoptotic program. With regard to the origin of signals inducing apoptosis, there are two ways of initiating caspase activation: (a) cellular death receptor-mediated activation; and (b) activation mediated by mitochondrial permeability and expression of the p53 oncogene. Both of these pathways are involved in atherogenesis. Oxidative stress, angiotensin II and cholesterol overload are the primary factors that induce apoptosis in vascular cells. Considering apoptosis in endothelial cells, exposed phosphatidylserine on the cell membrane activates thrombin increasing the probability of arterial thromboses. Further progression of atherosclerosis is promoted by the formation of apoptotic bodies with oxidized phospholipids exposed on the membrane; these also activate adhesion of monocytes. Apoptosis of smooth muscle cells is usually observed in the fibrous portion of an atherosclerotic plaque in which the cells produce collagen important for plaque stability. As apoptosis occurs in smooth muscle cells, the fibrous cap grows thinner. This can result in both plaque rupture, formation of thrombi as well as calcification of the plaque from apoptotic smooth muscle cells remnants. Smooth muscle cells apoptosis is beneficial in that it offers protection to the walls of arteries against proliferative restenosis induced by invasive procedures. Apoptosis of macrophages contributes to the formation and progression of the lipidic core and promotes thrombosis of atherosclerosis in damaged arteries. By contrast, apoptosis of macrophages diminishes the production of matrix methaloproteinases that decompose collagen fibers. New facts concerning the effects of antioxidants (selenium, vitamin C and vitamin E), inhibitors of angiotensin converting enzyme, beta-blockers, calcium chanel blockers, and statins are also considered in this review.

Apoptosis or programmed cell death is genetically determined process to destroy cells for the maintaining of cellular homeostasis in the tissue. This paper reviews the current knowledge on the molecular mechanisms of apoptosis. Activation of cysteine proteases called caspases plays a major role in the execution of apoptosis. These activated caspases selectively cleave cellular proteins, which result in apoptotic morphology (internucleosomal fragmentation of DNA into 180-200 base pair pieces, shrinkage of the cell and the nucleus as well and fragmentation of the cell into apoptotic bodies) and death of the cell. Now two pathways of caspase activation are reported. The first through triggering of cellular death-receptor superfamily. The second is mitochondrial pathway induced by the changes of the expression of pro- and anti-apoptotic genes in the cell. It leads to release of cytochrome c and apoptosis inducing factor from mitochondria. The paper reviews also currently used methods of detection of apoptotic cells in tissue samples, causes of false-positive or false-negative results of ISEL and TUNEL in situ reactions.

Objective: The present study was conducted to investigate tissue damage under prolonged oral administration of mice with cadmium chloride (CdCI2) with emphasis being placed on cadmium(Cd)-induced cell death in mice liver. MaterialandMethods. Juvenile (4- to 6-week-old) outbred mice were used in the experiments. Mice of the experimental group (n = 24) received drinking water supplemented with CdCI2 (250 mg elemental Cd/l) as the only drinking fluid for 8 weeks. Mice of the control group (n = 22) had free access to drinking water. All mice were terminated after 8 weeks. Protein synthesis was evaluated by incorporation of [14C]-labelIed leucine into newly synthesized peptides and proteins. Apoptosis of liver cells was histochemically detected by the TUNEL assay using in situ cell death detection kit, AP (Roche, Mannheim, Germany). Results: General toxic effect of Cd was assessed according to mice body weight gain and the relative weight index of organs. In respect to the control group, the body weight gain of experimental mice was 40–60% lower throughout the period of Cd-administration. Small but significant increment of the relative weight index of the kidney was also revealed in Cd-affected mice. In this group, intensities of protein synthesis in liver, kidney and the heart were significantly higher than in controls. In the sections of liver specimens from Cd-affected mice, the number of TUNEL+ cells containing fragmented nuclei was significantly higher than in control (p < 0.0001); median score was 1. Conclusion: Long-term oral administration by CdCl2 activates the synthesis of proteins and induces apoptotic cell death in the liver. [ABSTRACT FROM AUTHOR]