Little information is available about the effects of exposure to pulsed microwaves on neuronal Ca^2＋ signaling under non-thermal conditions. In this study, rat pheochromocytoma （PC12） cells were exposed to pulsed m...Little information is available about the effects of exposure to pulsed microwaves on neuronal Ca^2＋ signaling under non-thermal conditions. In this study, rat pheochromocytoma （PC12） cells were exposed to pulsed microwaves for 6 min at a specific absorption rate （SAR） of 4 W/kg to assess possible real-time effects. During microwave exposure, free calcium dynamics in the cytosol, mitochondria, and nucleus of cells were monitored by time-lapse microfluorimetry using a genetically encoded calcium indicator （ratiometric-pericam, ratiometric-10ericam-mt,展开更多
Calcium homeostasis in synaptosomes is altered during aging. The intrasynaptomal free calcium concentration ([Ca2+]i) was determined in 3- and 24-month-old rats treated with or without Rbl and Rgl. As expected, the [C...Calcium homeostasis in synaptosomes is altered during aging. The intrasynaptomal free calcium concentration ([Ca2+]i) was determined in 3- and 24-month-old rats treated with or without Rbl and Rgl. As expected, the [Ca2-]i level increased with age. Treatment with Rbl and Rgl elicited an obvious decrease of [Ca2+]i content, especially in aged rates. In addition, Rbl and Rgl significantly stimulated the activity of Na+, K+-ATPase while Rbl inhibited the activity of Ca2+, Mg2--ATPase arid calmodulin. In view of the close relationship of [Ca2-]i level with aging, the changes of [Ca2+]i induced by Rbl and Rgl, as shown by our results, might provide an explanation of the mechanisms of their antiaging function.展开更多
The effects of Arecoline (Are) on calcium m obilization were investigated. In isolated single ventricular m yocyte of guinea pig,patch clamp whole cell recording techniques were used to record the current of L - typ...The effects of Arecoline (Are) on calcium m obilization were investigated. In isolated single ventricular m yocyte of guinea pig,patch clamp whole cell recording techniques were used to record the current of L - type calcium channel and cytosolic Ca2 + level ([Ca2 + ]i) labeled with fluo- rescence probe Fluo- 3/ AM was m easured under a laser scanning confocal microscope.Results re- vealed that Are(3- 10 0 μm ol/ L) could inhibit L- type calcium current in a concentration- depen- dent manner and the value of IC50 was33.73μm ol/ L (n=5 ) .In the absence of extracellular calci- um,the resting levels of[Ca2 + ]i was not affected by Are(n=6 ,P>0 .0 5 ) ,but pretreatment with Are(30 μmol/ L) could significantly inhibit the[Ca2 + ]i elevation induced by caffeine(10 m mol/ L,n=6 ,P<0 .0 1) .It was concluded that Are could inhibit not only calcium influx through L- type calcium channel but also calcium release from sarcoplasm ic reticulum.展开更多
基金supported by the National Natural Science Foundation of China[No.31400716 and No.61401497]
文摘Little information is available about the effects of exposure to pulsed microwaves on neuronal Ca^2＋ signaling under non-thermal conditions. In this study, rat pheochromocytoma （PC12） cells were exposed to pulsed microwaves for 6 min at a specific absorption rate （SAR） of 4 W/kg to assess possible real-time effects. During microwave exposure, free calcium dynamics in the cytosol, mitochondria, and nucleus of cells were monitored by time-lapse microfluorimetry using a genetically encoded calcium indicator （ratiometric-pericam, ratiometric-10ericam-mt,
文摘Calcium homeostasis in synaptosomes is altered during aging. The intrasynaptomal free calcium concentration ([Ca2+]i) was determined in 3- and 24-month-old rats treated with or without Rbl and Rgl. As expected, the [Ca2-]i level increased with age. Treatment with Rbl and Rgl elicited an obvious decrease of [Ca2+]i content, especially in aged rates. In addition, Rbl and Rgl significantly stimulated the activity of Na+, K+-ATPase while Rbl inhibited the activity of Ca2+, Mg2--ATPase arid calmodulin. In view of the close relationship of [Ca2-]i level with aging, the changes of [Ca2+]i induced by Rbl and Rgl, as shown by our results, might provide an explanation of the mechanisms of their antiaging function.
基金Thisprojectwassupported by a grant from Natural Sci-ences Foundation of China(No. 396 70 6 6 1)
文摘The effects of Arecoline (Are) on calcium m obilization were investigated. In isolated single ventricular m yocyte of guinea pig,patch clamp whole cell recording techniques were used to record the current of L - type calcium channel and cytosolic Ca2 + level ([Ca2 + ]i) labeled with fluo- rescence probe Fluo- 3/ AM was m easured under a laser scanning confocal microscope.Results re- vealed that Are(3- 10 0 μm ol/ L) could inhibit L- type calcium current in a concentration- depen- dent manner and the value of IC50 was33.73μm ol/ L (n=5 ) .In the absence of extracellular calci- um,the resting levels of[Ca2 + ]i was not affected by Are(n=6 ,P>0 .0 5 ) ,but pretreatment with Are(30 μmol/ L) could significantly inhibit the[Ca2 + ]i elevation induced by caffeine(10 m mol/ L,n=6 ,P<0 .0 1) .It was concluded that Are could inhibit not only calcium influx through L- type calcium channel but also calcium release from sarcoplasm ic reticulum.
