Damage to erythrocytes from long-term heat stress

Abstract

1. Erythrocytes are known to haemolyse in vitro at 48-50 degrees C. We hypothesized that erythrocytes might be damaged at much lower temperatures if they are incubated for prolonged periods. Erythrocytes from healthy human donors (n = 7) were incubated at 37, 40, 42, 44, 46 or 48 degrees C for 4-48 h. The haemolytic percentage and osmotic fragility were then measured by a modification of the method of Parpart et al. 2. Significant haemolysis and increased fragility were not observed at any temperatures after incubation for 4 h. However, the haemolytic percentage increased after incubation for 24 h at 44 degrees C (9.1 +/- 4.9%, P less than 0.01), 46 degrees C (52.4 +/- 14.1%, P less than 0.01) and 48 degrees C (98.0 +/- 2.6%, P less than 0.01) and after incubation for 48 h at 42 degrees C (9.8 +/- 4.5%, P less than 0.01) when compared with the values before heating (1.1 +/- 0.9%). The osmotic fragility also increased after incubation for 24 h at and above 42 degrees C. 3. Although heat-induced haemolysis and an increase in fragility have not been known to occur below 48 degrees C, these were quite apparent after incubation for 24-48 h at only 42 degrees C. This suggests that with regard to thermal effects, it is important to consider not only the temperature but also the duration of heating.

Age-related changes of antioxidant enzyme activities, glutathione status and lipid peroxidation in rat erythrocytes after heat stress

“…Utoh and Harasaki (1992) reported an increase of membrane fragility in erythrocytes exposed to high in vitro temperatures. Several studies suggest that heat can increase oxidative stress in cells (Loven, 1988;Flanagan et al, 1998) and increase the reactivity of ROS such as H 2 O 2 .…”

Loss of Red Blood Cell Viability Associated with Limited Thermal Inactivation of Extracellular HIV-1

“…3) Damage to the cell membrane is affected not only by the temperature, but also by the duration of exposure. For ex ample, no significant immediate hemolysis was observed when erythrocytes were incubated at temperatures up to 48°C for 4 h [25], However, after 24 h exposure, hemolysis at 44 °C was about 9%, and at 48 °C it was 98%. Similarly, very little hemoglobin was released from erythrocytes heat ed at 47.4°C in PBS for exposure times less than about 350 min, but after about 650 min, about 50% were lysed [18].…”

Studies on Certain Heat Induced Changes of Erythrocyte Membrane with Supplementation of Ascorbic Acid and Alteration of Dietary Protein Level

“…The increased osmotic fragility was observed after incubation for 24 hrs at and above 42 0 C. Thus, it is important to consider not only the temperature but also the duration of heating [9]. Again, red cells are always under high oxygen pressure and extremely susceptible to peroxidation and the conditions that favour peroxidation, are seemingly optimal in red cells [10].…”

“…Erythrocytes are known to haemolyse in vitro at [48][49][50] 0 C. Significant haemolysis and increased fragility were not observed at any temperature after incubation for 4 hrs. [9].…”