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Effects of mydriatic agents on neutrophil migration
1Department of Pathology, University of Michigan Medical School, Ann Arbor.
Abstract:
We have investigated the effects of various mydriatic agents on the locomotion of polymorphonuclear leukocytes in vitro. Human as well as rat neutrophils showed a dose-dependent increase of migration into micropore filters when tested against cyclopentolate hydrochloride at a dose range between 16 and 63 micrograms/ml. At higher doses (250 micrograms/ml), a complete inhibition of neutrophil migration was observed. A commercially available cyclopentolate hydrochloride preparation showed identical effects. Little or no changes in neutrophil locomotion were seen with atropine, homatropine, scopolamine or tropicamide when tested at the same concentration range. Since addition of cyclopentolate to either the lower or upper compartment of the multiwell chemotaxis chamber gave virtually the same results, it is assumed that the drug most likely induces a chemokinetic neutrophil response. However, an additional chemotactic effect cannot be excluded. These in vitro observations may help to explain an accidental observation in a patient with severe anterior uveitis who showed a massive, localized leukocyte accumulation on the corneal endothelium after contact with a cyclopentolate-soaked cotton pledget.
Insights
Cyclopentolate hydrochloride enhances polymorphonuclear leukocyte migration at specific doses, but inhibits it at higher concentrations. This chemokinetic effect may explain leukocyte accumulation observed in a patient with anterior uveitis.
Area of Science:
- Ophthalmology
- Immunology
- Pharmacology
Background:
- Mydriatic agents are commonly used in ophthalmology.
- The effects of mydriatics on leukocyte function are not fully understood.
Purpose of the Study:
- To investigate the in vitro effects of mydriatic agents on polymorphonuclear leukocyte (neutrophil) locomotion.
- To determine if cyclopentolate hydrochloride influences neutrophil migration.
Main Methods:
- Human and rat neutrophils were used for in vitro studies.
- Neutrophil migration was assessed using micropore filters in a chemotaxis assay.
- Various concentrations of cyclopentolate hydrochloride and other mydriatics (atropine, homatropine, scopolamine, tropicamide) were tested.
Main Results:
- Cyclopentolate hydrochloride demonstrated a dose-dependent effect on neutrophil migration.
- Migration increased between 16 and 63 micrograms/ml, with complete inhibition at 250 micrograms/ml.
- Other tested mydriatics showed minimal effects on neutrophil locomotion.
- Cyclopentolate's effect was consistent regardless of its placement in the chemotaxis chamber, suggesting a chemokinetic action.
Conclusions:
- Cyclopentolate hydrochloride significantly influences neutrophil migration in a dose-dependent manner.
- The primary effect appears to be chemokinetic, although a chemotactic contribution cannot be ruled out.
- These findings may provide insight into clinical observations, such as localized leukocyte accumulation in patients treated with cyclopentolate.