Impact of rising temperature on physiological and biochemical alterations that affect the viability of blood cells in American bullfrog crossbreeds

Abstract

The study aimed to examine the impact of increasing environmental temperatures on physiological changes, oxidative stress, nitric oxide production, total antioxidant capacity, and blood cell viability in American bullfrog crossbreeds. Frogs and frog blood cells were exposed to temperature ranges of 25–33 °C and 25–37 °C, respectively. Physiological parameters (body temperature, pulse rate, ventilation rate, and oxygen saturation) and biochemical parameters (total antioxidant power, hydrogen peroxide, malondialdehyde, nitric oxide, and mitochondrial activity) were measured at every 2 °C increment. Results showed that body temperature rose with increased environmental temperature (P 0.05). Total antioxidant power at 25 °C was greater than at 27–37 °C (P < 0.05). Hydrogen peroxide levels at 27 °C were higher compared to 25 °C and 31–37 °C (P < 0.05). Malondialdehyde levels at 25–33 °C were higher than at 35 °C and 37 °C (P < 0.05). Nitric oxide levels at 37 °C were higher than at 25–33 °C (P < 0.05), and at 35 °C were higher than at 25–31 °C (P < 0.05). Blood cell viability at 25–31 °C was higher than at 37 °C (P < 0.05). These results suggest that at an environmental temperature of 33 °C, the frogs' body temperature approached 31 °C or higher, and were likely to be harmful to the frogs. Finally, the environmental temperature that caused frog blood cell death was 37 °C.

Keywords

• Amphibians
• Global warming
• High environmental temperature
• Heat stress
• Antioxidants
• Cell death