Open AccessTetramethylpyrazine protected photoreceptor cells of rats by modulating nuclear translocation of NF‐κB 1
Author(s) -
YANG Jinnan,
CHEN Jinmao,
LUO Lin,
LIN Shaochun,
LI Dai,
HU Shixing
Publication year - 2005
Publication title -
acta pharmacologica sinica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.514
H-Index - 90
eISSN - 1745-7254
pISSN - 1671-4083
DOI - 10.1111/j.1745-7254.2005.00141.x
Subject(s) - tetramethylpyrazine , apoptosis , tunel assay , retinal , chemistry , western blot , pharmacology , saline , downregulation and upregulation , endocrinology , biology , medicine , biochemistry , pathology , alternative medicine , gene
Aim: To evaluate the effect of tetramethylpyrazine (TMP) injection on retinal damage induced by N ‐methyl‐ N ‐nitrosourea (MNU) in rats and on nuclear factorkappa B (NF‐κB) family members. Methods: Female Sprague‐Dawley (SD) rats were randomly divided into groups: (i), control group; (ii), model group; and (iii), TMP‐injection groups, in which the rats were subdivided into 40 mg/kg, 80 mg/kg and 160 mg/kg groups. Drugs were injected ip into 47‐day‐old SD rats once a day. At 50 days of age, all rats in the model group and drug groups also received a single ip injection of 60 mg/kg MNU. Rats in group 1 received ip injection of physiological saline. All rats were killed at different times after MNU or physiological saline treatment. The apoptotic index of photoreceptor cells was calculated by TUNEL labeling; retinal damage was evaluated based on retinal thickness and the expression of NF‐κB family members was detected by Western blot. Results: TMP injections, in a dose‐dependent manner, suppressed photoreceptor cell apoptosis and decreased its loss in the peripheral retina. As compared with the MNU‐treated group, TMP injection at a dose of 160 mg/kg also time‐dependently upregulated the NF‐κB/p65 protein level in the nucleus and downregulated the IκBαprotein level in the cytoplasm. However, no protective effect of TMP injection on MNU‐induced central retinal damage was found. Conclusion: TMP injection partially protects against MNU‐induced retinal damage by upregulating the nuclear translocation of p65 to inhibit photoreceptor cells apoptosis.