Discerning Comparison of 1 and 0.5% Ethylene Glycol in Sprague-Dawley Rats with Modeled Urolithiasis

Area of Science:

• Nephrology
• Toxicology
• Animal Modeling

Background:

• Ethylene glycol is commonly used to model urolithiasis in rats.
• High concentrations (1-0.75%) can cause rapid disease progression and multi-organ toxicity.
• Ethical concerns limit the duration of experiments with high-dose ethylene glycol.

Purpose of the Study:

• To develop a safer, long-term rat model for studying urolithiasis.
• To assess the feasibility of using a lower concentration of ethylene glycol for chronic urolithiasis induction.
• To evaluate the absence of organ toxicity in this modified model.

Main Methods:

• Sprague-Dawley rats were administered a low concentration (0.5%) of ethylene glycol for six weeks.
• Animals were observed during a subsequent six-week recovery period.
• Urine and blood parameters were analyzed to monitor urolithiasis development and organ function.

Main Results:

• Urolithiasis signs, including ketones, decreased diuresis, and lower urine pH, appeared by week six.
• Elevated blood urea, protein, and hematocrit were observed.
• No leukocytes in urine, normal differential leukocyte count, and no elevation in ALT, creatinine, cholesterol, or triglycerides indicated an absence of organ failure.
• The 0.5% ethylene glycol model allowed for observation up to 12 weeks, unlike the 1% model stopped at week three due to ethical concerns.

Conclusions:

• A 0.5% ethylene glycol concentration in rats provides a viable long-term model for urolithiasis.
• This model effectively induces urolithiasis without causing significant multi-organ toxicity.
• The extended observation period in this modified model offers greater insight into disease progression and recovery.