Related Experiment Videos
Intrathecal tolerance of metrizamide in chloralose anesthetized cats
Abstract:
The water soluble radiopaque medium, metrizamide (Amipaque) was introduced into the lumbar subarachnoid space in chloralose anesthetized cats at a standard volume of 0.35 cc/kg in concentrations of 300 mgI/cc to 500 mgI/cc during EMG recording. These animals did not differ from controls which received cerebrospinal fluid under otherwise identical conditions; both groups usually showed some mild and occasional muscle fasciculations or mild spasms. Treatment with metrizamide appeared to be a less deleterious procedure than that using hyperosmotic sucrose (1.32 M) as judged from EMG records. In contrast, equivalent amounts of neglumine iothalamate produced frank convulsions in 7 of 15 cases and a range of hyperirritability in the remaining 8.
Insights
Metrizamide, a water-soluble radiopaque contrast agent, showed minimal neurological effects in cats compared to hyperosmotic sucrose. Neglumine iothalamate, however, induced significant convulsions and hyperirritability, indicating metrizamide
Area of Science:
- Neuroscience
- Radiology
- Pharmacology
Background:
- Metrizamide is a water-soluble, radiopaque contrast medium used in medical imaging.
- Assessing the neurotoxicity of contrast agents is crucial for patient safety.
- Electromyography (EMG) can detect neurological side effects.
Purpose of the Study:
- To evaluate the neurological safety of metrizamide administered intrathecally.
- To compare the neurotoxicity of metrizamide with other intrathecal agents.
Main Methods:
- Metrizamide was administered intrathecally in anesthetized cats at varying concentrations.
- Electromyography (EMG) was used to monitor neurological activity.
- Control groups received cerebrospinal fluid or hyperosmotic sucrose or negrumine iothalamate.
Main Results:
- Metrizamide administration resulted in mild, occasional muscle fasciculations or spasms, similar to controls.
- Metrizamide was less deleterious than hyperosmotic sucrose based on EMG.
- Neglumine iothalamate caused frank convulsions in 7/15 cats and hyperirritability in the rest.
Conclusions:
- Metrizamide appears to be a relatively safe intrathecal contrast agent with minimal neurotoxic effects.
- Metrizamide demonstrates a better safety profile compared to negrumine iothalamate and hyperosmotic sucrose.
- Further studies may be warranted to confirm these findings in different models.