Osmotic fragility during in vitro erythrocyte cytotoxicity induced by aluminium chloride, lead acetate or mercuric chloride in hyposmolar sucrose media

Erythrocyte death by eryptosis or erythronecrosis may induce erythrocyte shrinking or swelling with increase in osmotic resistance or fragility as indication of cytotoxicity. We investigated heterogeneous cytotoxic outcomes during in vitro exposure of goat erythrocytes to aluminium chloride, lead acetate or mercuric chloride using erythrocyte osmotic fragility (EOF) testing. The metallic salt solution (MSS) was added to 4.0 μL of high (100 mosmol/L) and low (250 mosmol/L) hyposmolar sucrose media at 0.3 or 0.4 mosmol/L concentration during testing of the osmotic fragility of 5.0 μL of blood from 10 goats. Hemolysis induced in the media (with and without MSS) was estimated in the supernatant with spectrophotometer at 540 nm. Osmotic stabilization or destabilization was calculated with probability for each test. Inducible osmotic resistance (IOR) was the ratio of mean stabilization to destabilization in both high and low hyposmolar media. Each MSS induced both osmotic resistance (stabilization) and fragility (destabilization) in varied media concentrations, with greater likelihood (P) of stabilization (0.93) or destabilization (0.77) in high or low media hyposmolarity, respectively. The EOF outcomes of the goats diverged within the group. High IOR induced by mercuric chloride (2.90) and low IOR by lead acetate (0.07) and aluminium chloride (0.04) reflected high stabilizing and destabilizing outcomes, respectively. In conclusion, MSS induced dual EOF outcomes (stabilization or destabilization) on the fragility domain, suggesting occurrence of both eryptosis (as stabilization) and erythronecrosis (as destabilization) at low exposure level, whereby biphasic, nonmonotonic or hormetic response to MSS toxic action might exist.