metallothionein and Testicular-Diseases

The widespread use of tributyltin (TBT) as biocides in antifouling paints and agricultural chemicals has led to environmental and marine pollution. Human exposure occurs mainly through TBT contaminated seafood and drinking water. It is a well known endocrine disruptor in mammals, but its molecular mechanism in testicular damage is largely unexplored. This study was therefore, designed to ascertain effects of tributyltin chloride (TBTC) on sertoli-germ cell co-culture in ex-vivo and in the testicular tissue in-vivo conditions. An initial Ca(2+) rise followed by ROS generation and glutathione depletion resulted in oxidative damage and cell death. We observed p38 and JNK phosphorylation, stress proteins (Nrf2, MT and GST) induction and mitochondrial depolarization leading to caspase-3 activation. Prevention of TBTC reduced cell survival and cell death by Ca(2+) inhibitors and free radical scavengers specify definitive role of Ca(2+) and ROS. Sertoli cells were found to be more severely affected which in turn can hamper germ cells functionality. TBTC exposure in-vivo resulted in increased tin content in the testis with enhanced Evans blue leakage into the testicular tissue indicating blood-testis barrier disruption. Tesmin levels were significantly diminished and histopathological studies revealed marked tissue damage. Our data collectively indicates the toxic manifestations of TBTC on the male reproductive system and the mechanisms involved.

Topics: Animals; Apoptosis; Blood-Testis Barrier; Calcium; Calcium Channel Blockers; Cell Death; Coculture Techniques; Coloring Agents; DNA Fragmentation; Enzyme Activation; Free Radical Scavengers; Germ Cells; Glutathione; Male; MAP Kinase Kinase 4; Membrane Potential, Mitochondrial; Metallothionein; Necrosis; Oxidation-Reduction; p38 Mitogen-Activated Protein Kinases; Phosphorylation; Rats; Reactive Oxygen Species; Sertoli Cells; Testicular Diseases; Testis; Trialkyltin Compounds

Several compounds have been shown to cause acute toxicity to cadmium (Cd). The mechanism of tolerance to Cd toxicity induced by glucocorticoids or by inflammation involves induction of metallothionein (MT) synthesis via glucocorticoid response elements or by inflammatory cytokines. We have demonstrated previously that the synthetic glucocorticoid dexamethasone suppresses inflammation-mediated induction of hepatic MT synthesis. Here we investigated the effect of glucocorticoid on tolerance to Cd induced by inflammation in mice. The LD50 of Cd for mice with induced inflammation by injection with turpentine oil (Tur-mice) was higher than the LD50 in control mice. Pretreatment of Tur-mice with dexamethasone to the Tur-mice (Dex+Tur-mice) resulted in a decrease in LD50 after Cd treatment. A significant increase in plasma alanine aminotransferase and aspartate aminotransferase levels in the Dex+Tur-mice was observed at lower doses of Cd than in the Tur-mice and at higher doses of Cd than in control mice. Dexamethasone did not suppress tolerance to cadmium toxicity in the testes of the Tur-mice. Pretreatment of Tur-mice with dexamethasone resulted in suppression of both plasma interleukin (IL)-6 elevation and in suppression of hepatic MT levels when induced by inflammation but not when induced by Cd. These data suggest that suppression of tolerance to Cd toxicity induced by glucocorticoid may involve hepatic MT synthesis mediated by inflammatory cytokines, such as IL-6. We suggest that the inflammatory response can modulate Cd toxicity by induction of MT by inflammatory cytokines.

Topics: Animals; Anti-Inflammatory Agents; Cadmium; Chemical and Drug Induced Liver Injury; Cytokines; Dexamethasone; Enzyme Induction; Glucocorticoids; Hemoglobins; Inflammation; Interleukin-6; Irritants; Kidney; Liver; Male; Metallothionein; Mice; Testicular Diseases; Tumor Necrosis Factor-alpha; Turpentine

Sensitivity to cadmium (Cd)-induced testicular injury varies greatly among mouse strains. For instance, 129/SvJ (129) mice are highly sensitive while C57BL/6J (C57) mice are refractory to Cd-induced testicular injury. Metallothionein (MT), a Cd-binding protein, is thought to be responsible for the strain susceptibility to Cd toxicity. In this study, MT-I/II knockout (MT-null) and wild-type 129 mice were used to determine the role of MT in Cd-induced testicular injury. Two additional strains of mice (C57 and the C57 x 129 F1cross) were also used to help define the role of genetic background in Cd toxicity. Mice were given 5-20 micromol/kg ip CdCl(2) and testicular injury was examined 24 h later by histopathology and testicular hemoglobin concentration. Cd produced dose-dependent testicular injury in all strains of mice, except for C57 mice, in which testicular injury could not be produced. MT-null mice were more sensitive than C57 x 129 mice but were equally sensitive as 129 mice to Cd-induced testicular injury. Fourteen days after 15 micromol/kg ip Cd administration, testicular atrophy was evident in MT-null, 129, and C57 x 129 mice but was absent in C57 mice. The resistance of C57 mice to Cd-induced testicular injury could not be attributed solely to a decreased uptake of (109)Cd nor to a greater amount of testicular MT. Microarray analysis revealed a higher expression of glutathione peroxidase in the testes of C57 mice, as well as genes encoding antioxidant components and DNA damage/repair, but their significance to Cd-induced injury is not immediately clear. Thus, this study demonstrates that it is genetic strain, not MT genotype, that is mechanistically important in determining susceptibility to Cd-induced testicular injury.

Topics: Animals; Cadmium; Crosses, Genetic; DNA Damage; DNA Repair; Genetic Predisposition to Disease; Genotype; Glutathione Peroxidase; Male; Metallothionein; Mice; Mice, Inbred C57BL; Mice, Knockout; Necrosis; Oligonucleotide Array Sequence Analysis; Organ Size; Phenotype; Species Specificity; Testicular Diseases; Testis

An experimental study was performed on orchiopathy (testis disorder) by using cadmium (Cd) and on the prevention of orchiopathy by the administration of selenium (Se). By a single administration of Cd 1.4 mg/kg (12.4 mumol/kg) or a second administration of Cd 1.4 mg/kg 24 hr after the administration of Cd 1.0 mg/kg (8.9 mumol/kg), the testis of a mouse showed ex-tensive necrosis, and an extreme decrease of glutathione (GSH) concentration accompanied by an increase of thiobarbituric acid reactive substances (TBARS). When Se 1.4 mg/kg (17.7 mumol/kg) was given at the same time as Cd 1.0 mg/kg, the disorder was completely prevented and their serum Cd and Se concentrations were 1165 +/- 268 ng/ml and 534 +/- 128 ng/ml, respectively. However, when Se was given, separately from the Cd administration, either 24 hr or 72 hr before Cd administration, no effect to prevent testis disorder was found. On the other hand, when Se 1.4 mg/kg and Cd 1.0 mg/kg were given simultaneously and then Cd 1.4 mg/kg was administered 24 hr and 72 hr after the simultaneous injection, respectively, there was no sign of disorder caused by the second administration of Cd. When Cd was given after administration of Cd and Se, Cd concentration in the testis (0.88 +/- 0.078 microgram/g and 0.77 +/- 0.03 microgram/g) was about twice as much as the concentration in the case of no administration of Se (0.30 +/- 0.04 microgram/g). The testicular dysfunction could not be explained by the increased Cd concentration in the testis. The groups with high Cd concentration in the testis were accompanied by an increase in metallothionein (92.8 +/- 18.6 micrograms/g and 92.5 +/- 7.3 micrograms/g), but these did not exceed the level of the control group (94.5 +/- 8.4 micrograms/g) which had neither Cd nor Se injections. In the groups with testicular necrosis, concentrations of zinc (Zn) and magnesium (Mg) were decreased while an increase in concentrations of calcium (Ca) and iron (Fe) was observed. These results suggest that Se concentration must be maintained to prevent the testicular disorder caused by Cd.

Topics: Animals; Cadmium; Drug Interactions; Glutathione; Male; Metallothionein; Mice; Mice, Inbred ICR; Necrosis; Selenium; Testicular Diseases; Testis; Thiobarbituric Acid Reactive Substances

To study the testicular injury by Cd from the viewpoint of essential element levels, male mice were injected with Cd subcutaneously at a dose of 30 mumol/kg body weight singly and the concentrations of 8 elements (Na, Mg, P, K, Ca, Fe, Zn, and Cd) in the testis were measured for 6 weeks. The most pronounced alteration was an increase of Ca content with time after the injection; the experimental group had 270 times more Ca than the control despite a decrease of the testis weight to one-third of the control at 4 weeks. K content decreased markedly and Fe remained at an elevated level throughout the experimental period. Decreased Mg, P, and Zn levels started to be restored after 2 weeks. Metallothionein (MT)-like Zn-binding proteins were studied in the cytosol fraction with a high performance liquid chromatograph-atomic absorption spectrophotometer. MT-like proteins were observed at a higher concentration in the control than in the Cd-injected group. No indications of new induction of MTs or MT-like proteins could be detected.

Topics: Animals; Cadmium; Chromatography, Gel; Male; Metallothionein; Metals; Mice; Mice, Inbred ICR; Organ Size; Testicular Diseases; Time Factors

Topics: Aging; Animals; Cadmium Poisoning; Fertility; Male; Metallothionein; Organ Size; Rats; Testicular Diseases; Testis