Organotin compounds produce neurotoxic and immunotoxic effects. Organotins may directly activate glial cells contributing to neuronal cell degeneration by local release of pro-inflammatory cytokines, tumor necrosis factor-_, and/or interleukins. They may also induce apoptosis by direct action on neuronal cells. Organotin compounds stimulate the neuronal release of and/or decrease of neuronal cell uptake of neurotransmitters in brain tissue, including aspartate, GABA, glutamate, norepinephrine, and serotonin. This may be either a contributing factor to or result of the neuronal cell loss. The immunotoxic effects of organotins are characterized by thymic atrophy caused by the suppression of proliferation of immature thymocytes and apoptosis of mature thymocytes. Organotin compounds are believed to exert these effects by suppressing DNA and protein synthesis, inducing the expression of genes involved in apoptosis (such as nur77), and disrupting the regulation of intracellular calcium levels, giving rise to the uncontrolled production of reactive oxygen species, release of cytochrome c to the cytosol, and the proteolytic and nucleolytic cascade of apoptosis. The suppression of proliferation of immature thymocytes further results in the suppression of T-cell-mediated immune responses. Organotins are also endocrine disruptors and are believed to contribute to obesity by inappropriate receptor activation, leading to adipocyte differentiation. Inorganic tin triggers eryptosis, contributing to tin-induced anemia. Bromine is a powerful oxidizing agent and is able to release oxygen free radicals from the water in mucous membranes. These free radicals are also potent oxidizers and produce tissue damage. In additon, the formation of hydrobromic and bromic acids will result in secondary irritation. The bromide ion is also known to affect the central nervous system, causing bromism. This is believed to be a result of bromide ions substituting for chloride ions in the in actions of neurotransmitters and transport systems, thus affecting numerous synaptic processes. (L626, L627, A543, L308, A182, A184)