|
|
This is only a preview of the paper
Click here to register and get the full text.
Existing members click here to login
|
|
|
Calcium transport study of SF-9 lepidopteran cells and bull frog sympathetic ganglion cells
ABSTRACT The intracellular calcium level and the calcium efflux of the bull-frog sympathetic ganglion cells (BSG) and the SF-9 lepidopteran ovarian cells were investigated using a calcium-sensitive fluorescence probe fura-2. It was found that the intracellular calcium levels were 58. ... The calcium effluxes following zero calcium solution were 2. ... The calcium effluxes following sodium orthovanadate (Na2VO4) in zero calcium solution were 6. ... The SF-9 cells also lost the ability to extrude intracellular calcium after 2-3 applications of Na2VO4 while the BSG cells showed no apparent lost of calcium extruding abilities for up to 4 applications of Na2VO4. ... Since calcium is involved in many cells activities such as acting as a secondary messenger, it is important for cells to control their intracellular calcium level. This study was aimed toward looking at the some of the basic properties of the SF-9 cells such as resting calcium concentration and rate of calcium extrusion after being calcium level being raised by an ionophore 4-bromo-A23187. The effect of sodium orthovanadate (an active transport inhibitor) on calcium extrusion was also looked at. Microspectrofluorescence techniques and the calcium-sensitive probe fura-2 were used to measure the intracellular calcium concentration of these cells. ...
It was found that the SF-9 cells appeared to have a calcium concentration similar to the BSG cells. Moreover, the calcium extrusion rates of both cell types with no Na2VO4 added seemed to the same. ... From the data available, it suggested that the BSG cells rate of calcium extrusion was enhanced by the Na2VO4 and was greater than the SF-9 cells. It was more important to note that the calcium extruding capabilities of the SF-9 cell seemed to impaired after two to three applications of Na2VO4 but it had apparent effects on the BSG cells even up to 4 applications.
After obtaining these basic parameters, many questions raised such as how does the SF-9 cells extrude their calcium and why the Na2VO4 affected the calcium efflux for the SF-9 cells but not the BSG cells? The SF-9 cells may have a calcium pump or exchanger to extrude their calcium and they may be very sensitive to the ATP (adenosine 3-triphosphate) supply. This was apparently different from the BSG cells since their calcium extrusion were not affected by the Na2VO4. ... The calcium free Ringer solution (0CaNRS) is the same as the NRS except CaCl2 was substituted with 2. ...
Intracellular calcium measurements
Fura-2 is a fluorescence indicator of calcium that is used to determine the free intracellular calcium concentration. ...
The experimental methods of calcium measurements used in the experiments were similar to the one described by Schwartz et al. ... In brief, intracellular free calcium concentration can be determined through the following formula (Grynkiewicz et al. ... (R-Rmin)/(Rmax-R)
where Kd is the effective dissociation constant for the Ca2+-fura-2 complex, Fmin and Fmax are the fluorescence intensities at SYMBOL 108 f "Symbol"=380nm obtained from calcium-free fura-2 sample and calcium-bound fura-2 sample respectively, R is the fluorescence intensities ratio obtained with excitation at 340 and 380nm (R = F340/F380), Rmin and Rmax are the F340/F380 ratios of the calcium-free and calcium-saturated fura-2 sample respectively.
Approximate Word count = 2715
Approximate Pages = 10.9
(250 words per page double spaced)
|
|
|
|
|
|