Abstract
Purpose: :
Saline solutions such as NaCl 0.9% are widely used in ophthalmology as excipient in eye drops, as rinse solutions for contact lens, or as intraocular implants conditioners. The aim of this study was to compare different saline and controlled ionization solutions to evaluate their possible effects on P2X cell death receptor.
Methods: :
Chang conjunctival were incubated with different ionic solutions (PBS, BSS, NaCl 0.9%) and controlled ionization solutions containing different cations for 15 minutes to 1 hour. Zn2+, Ca2+ or Mg2+ were also tested. Cold light cytofluorometry was performed to evaluate cell viability (neutral red test), reactive oxygen species (ROS) production (dichlorofluorescein diacetate and hydroethidine tests), and P2X cell death purinoreceptor activation (YO–PRO–1 test). The cytoprotective effect of controlled ionization solutions towards ATP stimulation of the purinoreceptor was also evaluated.
Results: :
The tested solutions showed different profiles: controlled ionization solutions induced a decrease in purinoreceptor activation contrary to PBS and BSS. A comparison between Zn2+, Ca2+ and Mg2+ showed that Zn2+ was the most effective cation to decrease P2X cell death receptor activation. Controlled ionization solutions containing Zn2+ cation block the ATP activation of P2X purinoreceptor.
Conclusions: :
Precautions should be taken concerning currently used buffers and saline solutions because they may induce long term cytotoxic effects on ocular surface. Controlled ionization solutions seem to be preferable as rinse solutions as they modulate P2X cell death and inflammation receptor. They could be associated with hyaluronic acid for example to prevent dry eye syndrom.
Keywords: receptors • conjunctiva • apoptosis/cell death