Short peptide sequences of ACTH 1-39 (the ACTH 4-9 analog Org 2766, ACTH 4-10 and its analog BIM 22015, and ACTH 1-13 [alpha-MSH]), which do not stimulate the adrenal cortex, have profound effects on the developing and regenerating neuromuscular system, in neonatal and in adult rats. Both development and regeneration are accelerated, as indicated by improved morphological, electrophysiological, behavioral and biochemical parameters. Regeneration in the central nervous system is problematic but the ACTH peptides may provide protection for CNS neurons, enhance denervation sensitivity or permit compensatory processes which facilitate functional recovery. Neuronal cells in culture respond to ACTH peptides by greater neurite outgrowth, and in some cell types, by increased B-50 expression. In all cases, susceptibility to ACTH peptide treatment varies with cell type, age, the specific peptide administered, its dosage and pattern of administration. External stress and the gender of the animal are additional factors that interact with the neurotrophic actions of the melanocortins.
Extracellular superoxide dismutase (EC-SOD, EC 1.15.1.1) is a major antioxidant enzyme that is located in the extracellular matrix and on the cell surface. EC-SOD protects against cell and tissue damage initiated by extracellular-produced reactive oxygen species (ROS). We investigated a major role of EC-SOD in the development of tumor formation. In this study, we reported that skin-specific overexpressed EC-SOD transgenic mice showed half the number of tumors compared with the nontransgenic mice in the dimethylbenzanthracene (DMBA)-initiated and a 12-O-tetradecanoylphorbol-13-acetate (TPA)-promoted two-stage skin carcinogenesis model. This model showed a significant increase of the epidermal cell proliferation in the nontransgenic mice, but the proliferative response in the transgenic mice was delayed. The 8-hydroxy-2'-deoxyguanosine (8OH-dG) detection assay showed that the oxidative DNA damage was significantly higher in the nontransgenic mice than in the transgenic mice after TPA treatments. Overall, EC-SOD overexpression inhibited the TPA-induced cell proliferation and DNA damage, and reduced the subsequent formation of tumors. Our data suggest that EC-SOD plays a protective role in DMBA/TPA-induced skin carcinogenesis.
In this study, we investigated the relationship between seasonal/annual variation in water masses and nutrients, and the effects of nutrients on phytoplankton assemblages in the western Korea/ Tsushima Strait. We collected water samples at least once per month from March 2006 to January 2008. There was seasonal variation in nutrient concentrations, with higher values in winter than in summer, and there was annual variation in chlorophyll-a concentration and phytoplankton abundance during spring, with values being approximately three and 10 times higher, respectively, in 2007 than in 2006. Phytoplankton abundance was also approximately four times higher in 2007 than in 2006 during the stratification periods. Our findings suggest that when the supply of nutrients to the upper layer is increased as a result of the Tsushima Warm Water Current and the effect of typhoons, they regulate the abundance and composition of phytoplankton assemblages in the Korea/Tsushima Strait, inducing a succession from flagellates to diatoms.
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