Melanin content and hydroperoxide metabolism in human melanoma cells
Human melanoma cells were grown to exponential and stationary phases showing melanin contents of 4.2 ± 0.3 and 11.3 ± 0.6 μg/10 6 cells, respectively. The cells were separated in four subpopulations by a Percoll gradient; the subpopulation of density 1.07 (g/ml) was the most enriched in pigmented ce...
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1991
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paper:paper_00144827_v196_n2_p172_Bustamante2023-06-08T14:37:16Z Melanin content and hydroperoxide metabolism in human melanoma cells Guerra, Liliana Noemí catalase hydroperoxide melanin article cell growth cell level chemoluminescence human human cell melanoma cell priority journal Catalase Cell Division Cell Line Cell Survival Cytosol Glutathione Peroxidase Human Hydrogen Peroxide Luminescence Melanins Melanoma Oxygen Consumption Superoxide Dismutase Support, Non-U.S. Gov't Human melanoma cells were grown to exponential and stationary phases showing melanin contents of 4.2 ± 0.3 and 11.3 ± 0.6 μg/10 6 cells, respectively. The cells were separated in four subpopulations by a Percoll gradient; the subpopulation of density 1.07 (g/ml) was the most enriched in pigmented cells and produced 28 and 58% of the cells in exponential and stationary phases, respectively. Melanoma cells had similar superoxide dismutase and glutathione peroxidase activities in exponential and stationary phases. Moreover melanoma cells exhibited a higher catalase activity in the stationary phase: whole homogenate and cytosol activities were 7.0 ± 0.3 and 10.8 ± 0.6 U/mg protein, whereas in exponential phase the activities were 4.9 ± 0.1 and 7.6 ± 0.3 U/mg protein for whole homogenate and cytosol, respectively. The intracellular H 2 O 2 steady-state concentration was 3.3 ± 0.2 and 2.1 ± 0.2 μM H 2 O 2 for exponential and stationary phases, respectively. The spontaneous chemiluminescence of the two culture phases was 169 ± 27 cps/10 6 cells (exponential) and 78 ± 24 cps/10 6 cells (stationary). The cytotoxicity of H 2 O 2 generated extracellularly by glucose oxidase was determined after 60 min of exposure. IC 50 values for exponential and stationary cell cultures were 0.9 and 2.4 mU/ml of glucose oxidase, respectively. The increased catalase activities in the stationary phase as compared with the exponential phase are consistent with the decreased intracellular H 2 O 2 , with the decreased spontaneous chemiluminescence, and with the increased resistance to exogenous H 2 O 2 . © 1991. Fil:Guerra, L. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. 1991 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00144827_v196_n2_p172_Bustamante http://hdl.handle.net/20.500.12110/paper_00144827_v196_n2_p172_Bustamante |
| institution |
Universidad de Buenos Aires |
| institution_str |
I-28 |
| repository_str |
R-134 |
| collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| topic |
catalase hydroperoxide melanin article cell growth cell level chemoluminescence human human cell melanoma cell priority journal Catalase Cell Division Cell Line Cell Survival Cytosol Glutathione Peroxidase Human Hydrogen Peroxide Luminescence Melanins Melanoma Oxygen Consumption Superoxide Dismutase Support, Non-U.S. Gov't |
| spellingShingle |
catalase hydroperoxide melanin article cell growth cell level chemoluminescence human human cell melanoma cell priority journal Catalase Cell Division Cell Line Cell Survival Cytosol Glutathione Peroxidase Human Hydrogen Peroxide Luminescence Melanins Melanoma Oxygen Consumption Superoxide Dismutase Support, Non-U.S. Gov't Guerra, Liliana Noemí Melanin content and hydroperoxide metabolism in human melanoma cells |
| topic_facet |
catalase hydroperoxide melanin article cell growth cell level chemoluminescence human human cell melanoma cell priority journal Catalase Cell Division Cell Line Cell Survival Cytosol Glutathione Peroxidase Human Hydrogen Peroxide Luminescence Melanins Melanoma Oxygen Consumption Superoxide Dismutase Support, Non-U.S. Gov't |
| description |
Human melanoma cells were grown to exponential and stationary phases showing melanin contents of 4.2 ± 0.3 and 11.3 ± 0.6 μg/10 6 cells, respectively. The cells were separated in four subpopulations by a Percoll gradient; the subpopulation of density 1.07 (g/ml) was the most enriched in pigmented cells and produced 28 and 58% of the cells in exponential and stationary phases, respectively. Melanoma cells had similar superoxide dismutase and glutathione peroxidase activities in exponential and stationary phases. Moreover melanoma cells exhibited a higher catalase activity in the stationary phase: whole homogenate and cytosol activities were 7.0 ± 0.3 and 10.8 ± 0.6 U/mg protein, whereas in exponential phase the activities were 4.9 ± 0.1 and 7.6 ± 0.3 U/mg protein for whole homogenate and cytosol, respectively. The intracellular H 2 O 2 steady-state concentration was 3.3 ± 0.2 and 2.1 ± 0.2 μM H 2 O 2 for exponential and stationary phases, respectively. The spontaneous chemiluminescence of the two culture phases was 169 ± 27 cps/10 6 cells (exponential) and 78 ± 24 cps/10 6 cells (stationary). The cytotoxicity of H 2 O 2 generated extracellularly by glucose oxidase was determined after 60 min of exposure. IC 50 values for exponential and stationary cell cultures were 0.9 and 2.4 mU/ml of glucose oxidase, respectively. The increased catalase activities in the stationary phase as compared with the exponential phase are consistent with the decreased intracellular H 2 O 2 , with the decreased spontaneous chemiluminescence, and with the increased resistance to exogenous H 2 O 2 . © 1991. |
| author |
Guerra, Liliana Noemí |
| author_facet |
Guerra, Liliana Noemí |
| author_sort |
Guerra, Liliana Noemí |
| title |
Melanin content and hydroperoxide metabolism in human melanoma cells |
| title_short |
Melanin content and hydroperoxide metabolism in human melanoma cells |
| title_full |
Melanin content and hydroperoxide metabolism in human melanoma cells |
| title_fullStr |
Melanin content and hydroperoxide metabolism in human melanoma cells |
| title_full_unstemmed |
Melanin content and hydroperoxide metabolism in human melanoma cells |
| title_sort |
melanin content and hydroperoxide metabolism in human melanoma cells |
| publishDate |
1991 |
| url |
https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00144827_v196_n2_p172_Bustamante http://hdl.handle.net/20.500.12110/paper_00144827_v196_n2_p172_Bustamante |
| work_keys_str_mv |
AT guerraliliananoemi melanincontentandhydroperoxidemetabolisminhumanmelanomacells |
| _version_ |
1768543307387895808 |