Acute copper intoxication after a Cu-Ca EDTA injection in rats

Area of Science:

• Toxicology
• Biochemistry
• Pharmacology

Background:

• Copper-calcium EDTA (Cu-Ca EDTA) is used therapeutically for copper deficiency.
• Overdosing with Cu-Ca EDTA can lead to rapid toxicity and mortality.
• The rate of copper release and transference is critical in understanding Cu-Ca EDTA toxicity.

Purpose of the Study:

• To investigate the relationship between Cu-Ca EDTA dosage, copper (Cu) transference rate, and acute toxicity in rats.
• To determine whether the rate of Cu transfer or total Cu accumulation is responsible for acute liver and kidney damage.

Main Methods:

• Thirty rats were divided into six groups, with five receiving varying doses of Cu-Ca EDTA (4-64 mg/kg) and one control group.
• Rats were observed for mortality post-injection; surviving rats were sacrificed at 24 hours.
• Liver and kidney tissues were analyzed for copper content and pathological changes (degeneration, hemorrhage, necrosis).

Main Results:

• Mortality occurred rapidly in high-dose groups (2-7 hours post-injection).
• The rate of Cu transference to the liver increased linearly with the injected dose.
• Dose-dependent liver and kidney degeneration, hemorrhage, and necrosis were observed, increasing with Cu dose.
• Liver Cu accumulation peaked at a moderate dose (13 mg/kg), decreasing at the highest dose (64 mg/kg).

Conclusions:

• In acute copper poisoning, the rapid rate of Cu transfer, not total accumulation, drives liver and kidney damage.
• High Cu transfer rates likely exceed cellular deposition mechanisms, leading to cytotoxic free copper and necrosis.
• This contrasts with chronic copper poisoning, where total accumulation is the primary factor in organ damage.