Paclitaxel is used for the treatment of several types of cancers.
However, one of the significant limiting complications of
paclitaxel is painful peripheral neuropathy during its therapy. In
this study we examined the engagement of antioxidative signal
pathway of the dorsal root ganglion (DRG) in mechanical and
thermal hypersensitivity evoked by paclitaxel. Behavioral test was
performed to determine mechanical and thermal sensitivity in
rats. Western blot analysis and ELISA were used to examine
expression of Nrf2-antioxidant response element (ARE) and
superoxide dismutases (SOD); and the levels of products of
oxidative stress in the DRG. Our results show that paclitaxel
increased mechanical and thermal sensitivity as compared with
vehicle control animals. Paclitaxel also impaired Nrf2-ARE and
SOD in the DRG and amplified products of oxidative stress,
namely 8-isoprostaglandin F2α and 8-hydroxy-2’-
deoxyguanosine. Systemic administration of SOD mimetic using
tempol, antioxidant vitamin C or blocking oxidative pathway
using NADPH oxidase inhibitor (GKT137831) attenuated
mechanical and thermal hypersensitivity induced by paclitaxel.
This inhibitory effect was accompanied with decreases of
proinflammatory cytokines (PICs) such as IL-1β, IL-6 and TNF-α
in the DRG. In conclusion, the data revealed impairment of
Nrf2-ARE and heightened oxidative and PIC signals in the DRG of
paclitaxel rats, leading to neuropathic pain. Balancing of reactive
oxygen species by supplying antioxidants and/or inhibiting
NADPH oxidase appears significant to yield beneficial effects in
neuropathic pain conditions after chemotherapeutic paclitaxel.
Two foxtail millet (Setaria italica L.) varieties were subjected to different shading intensity treatments during a grain-filling stage in a field experiment in order to clarify physiological mechanisms of low-light effects on the yield. Our results showed that the grain fresh mass per panicle, yield, photosynthetic pigment contents, net photosynthetic rate, stomatal conductance, effective quantum yield of PSII photochemistry, and electron transport rate decreased with the increase of shading intensity, whereas the intercellular CO2 concentration increased in both varieties. In addition, shading changed a double-peak diurnal variation of photosynthesis to a one-peak curve. In conclusion, the lower yield of foxtail millet was caused mainly by a reduction of grain mass assimilated, a decline in chlorophyll content, and the low photosynthetic rate due to low light during the grain-filling stage. Reduced light energy absorption and conversion, restricted electron transfer, and reduced stomatal conductance might cause the decrease in photosynthesis., X. Y. Yuan, L. G. Zhang, L. Huang, X. Qi, Y. Y. Wen, S. Q. Dong, X. E. Song, H. F. Wang, P. Y. Guo., and Obsahuje bibliografii