[Fluorescence quantification of intracellular calcium of rat smooth muscle cells].

Objective: To explore the kinetic changes of calcium in rat smooth muscle cells and establish a method for quantification of intracellular calcium.

Methods: Rat mesenteric arteriolar smooth muscle cells (ASMCs) were isolated and the kinetic changes of calcium were measured using highly sensitive Ca2+ fluorescent probe indo-1 with laser scanning confocal microscopy (LSCM). The dissociation constant values (Kd) of the fluorescent probe indo-1 was measured at 37 degrees Celsius, and according to the conversion formula from fluorescence intensity to concentration, the concentration of Ca2+ was calculated.

Results: Analysis of the fluorescent images using LSCM showed that [Ca2+]i in the ASMCs were significantly elevated in response to stimulation with dexamethasone, and spontaneous calcium waves as well as intracellular calcium overloading were observed occasionally.

Conclusion: Fluorescence quantification with LSCM is applicable for detecting the kinetic changes of intracellular [Ca2+]i.