ABSTRACT
Nonylphenol (NP) as an environment contaminant has been demonstrated to adversely affect male reproduction. The main objective of this study was to evaluate NP-induced oxidative stress and toxicity in testicular Sertoli cells. Sertoli cells were exposed to 10-40 microM NP for 24 h. Cell death and growth inhibition were observed by flow cytometric analysis and 3-[4,5-dimethylthiazol-2yl]-2,5-diphenyltetrazolium bromide (MTT) assay, while fluorescein diacetate (FDA) and propidium iodide (PI) staining was used to examine the morphological changes following NP exposure. Subsequently, we found that short-term treatment (2 h) of NP caused intracellular accumulation of reactive oxygen species (ROS), which was evaluated by loading of 2',7'-dichlorodihydrofluorescein diacetate (DCFH-DA) without visible morphological changes. Loss of mitochondrial membrane potential (MMP) was detected following 12 and 24 h treatment of NP and assessment by Rhodamine 123 (Rh123) staining. In addition, incubation with NP for 12 h also increased lipid peroxidation of Sertoli cells. These results indicated that low micromolar concentrations of NP induce an adverse oxidative stress in rat Sertoli cells.
Subject(s)
Oxidative Stress/drug effects , Phenols/toxicity , Sertoli Cells/drug effects , Animals , Cell Size/drug effects , Cell Survival/drug effects , Cells, Cultured , Dose-Response Relationship, Drug , Flow Cytometry/methods , Lipid Peroxidation/drug effects , Male , Membrane Potential, Mitochondrial/drug effects , Microscopy, Fluorescence , Rats , Rats, Sprague-Dawley , Reactive Oxygen Species/analysis , Reactive Oxygen Species/metabolism , Sertoli Cells/pathologyABSTRACT
Male Sprague-Dawley (SD) rats were exposed to 4-t-nonylphenol (NP) by gavage at dosages of 0, 125 and 250 mg/kg/day for 50 days. Organ weights of liver, kidney, testis and epididymis were measured. Sperm number in the head of epididymis was counted. Several hormones including testosterone, luteinizing hormone and follicle stimulating hormone were measured. Testicular sections were observed by light and electron microscopy. Terminal dideoxynucleotidyl transferase dUTP nick end labeling assay was performed to probe the apoptotic cells in seminiferous tubules. When rats were treated with nonylphenol at 250 mg/kg/day, the absolute and relative weight of epididymis decreased dramatically, while the relative weights of kidney and liver increased by 14 and 22%, respectively. In addition, the sperm density of the head of epididymis and the testosterone level descended at 250 mg/kg/day. The levels of luteinizing hormone and follicle stimulating hormone increased in both nonylphenol treated groups. Pathological changes were detected by microscopy and the transferase dUTP nick end labeling (TUNEL) assay showed that the number of apoptotic cells in testes increased with nonylphenol in a dose-dependent manner.
